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* mm, soft-offline: convert parameter to pfnNaoya Horiguchi2019-12-011-6/+1
| | | | | | | | | | | | | | | Currently soft_offline_page() receives struct page, and its sibling memory_failure() receives pfn. This discrepancy looks weird and makes precheck on pfn validity tricky. So let's align them. Link: http://lkml.kernel.org/r/20191016234706.GA5493@www9186uo.sakura.ne.jp Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Hildenbrand <david@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: fix try_offline_node()David Hildenbrand2019-11-161-0/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | try_offline_node() is pretty much broken right now: - The node span is updated when onlining memory, not when adding it. We ignore memory that was mever onlined. Bad. - We touch possible garbage memmaps. The pfn_to_nid(pfn) can easily trigger a kernel panic. Bad for memory that is offline but also bad for subsection hotadd with ZONE_DEVICE, whereby the memmap of the first PFN of a section might contain garbage. - Sections belonging to mixed nodes are not properly considered. As memory blocks might belong to multiple nodes, we would have to walk all pageblocks (or at least subsections) within present sections. However, we don't have a way to identify whether a memmap that is not online was initialized (relevant for ZONE_DEVICE). This makes things more complicated. Luckily, we can piggy pack on the node span and the nid stored in memory blocks. Currently, the node span is grown when calling move_pfn_range_to_zone() - e.g., when onlining memory, and shrunk when removing memory, before calling try_offline_node(). Sysfs links are created via link_mem_sections(), e.g., during boot or when adding memory. If the node still spans memory or if any memory block belongs to the nid, we don't set the node offline. As memory blocks that span multiple nodes cannot get offlined, the nid stored in memory blocks is reliable enough (for such online memory blocks, the node still spans the memory). Introduce for_each_memory_block() to efficiently walk all memory blocks. Note: We will soon stop shrinking the ZONE_DEVICE zone and the node span when removing ZONE_DEVICE memory to fix similar issues (access of garbage memmaps) - until we have a reliable way to identify whether these memmaps were properly initialized. This implies later, that once a node had ZONE_DEVICE memory, we won't be able to set a node offline - which should be acceptable. Since commit f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") memory that is added is not assoziated with a zone/node (memmap not initialized). The introducing commit 60a5a19e7419 ("memory-hotplug: remove sysfs file of node") already missed that we could have multiple nodes for a section and that the zone/node span is updated when onlining pages, not when adding them. I tested this by hotplugging two DIMMs to a memory-less and cpu-less NUMA node. The node is properly onlined when adding the DIMMs. When removing the DIMMs, the node is properly offlined. Masayoshi Mizuma reported: : Without this patch, memory hotplug fails as panic: : : BUG: kernel NULL pointer dereference, address: 0000000000000000 : ... : Call Trace: : remove_memory_block_devices+0x81/0xc0 : try_remove_memory+0xb4/0x130 : __remove_memory+0xa/0x20 : acpi_memory_device_remove+0x84/0x100 : acpi_bus_trim+0x57/0x90 : acpi_bus_trim+0x2e/0x90 : acpi_device_hotplug+0x2b2/0x4d0 : acpi_hotplug_work_fn+0x1a/0x30 : process_one_work+0x171/0x380 : worker_thread+0x49/0x3f0 : kthread+0xf8/0x130 : ret_from_fork+0x35/0x40 [david@redhat.com: v3] Link: http://lkml.kernel.org/r/20191102120221.7553-1-david@redhat.com Link: http://lkml.kernel.org/r/20191028105458.28320-1-david@redhat.com Fixes: 60a5a19e7419 ("memory-hotplug: remove sysfs file of node") Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") # visiable after d0dc12e86b319 Signed-off-by: David Hildenbrand <david@redhat.com> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Keith Busch <keith.busch@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Jani Nikula <jani.nikula@intel.com> Cc: Nayna Jain <nayna@linux.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/base/memory.c: don't access uninitialized memmaps in ↵David Hildenbrand2019-10-191-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | soft_offline_page_store() Uninitialized memmaps contain garbage and in the worst case trigger kernel BUGs, especially with CONFIG_PAGE_POISONING. They should not get touched. Right now, when trying to soft-offline a PFN that resides on a memory block that was never onlined, one gets a misleading error with CONFIG_PAGE_POISONING: :/# echo 5637144576 > /sys/devices/system/memory/soft_offline_page [ 23.097167] soft offline: 0x150000 page already poisoned But the actual result depends on the garbage in the memmap. soft_offline_page() can only work with online pages, it returns -EIO in case of ZONE_DEVICE. Make sure to only forward pages that are online (iow, managed by the buddy) and, therefore, have an initialized memmap. Add a check against pfn_to_online_page() and similarly return -EIO. Link: http://lkml.kernel.org/r/20191010141200.8985-1-david@redhat.com Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e86b319] Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: <stable@vger.kernel.org> [4.13+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/base/memory.c: don't store end_section_nr in memory blocksDavid Hildenbrand2019-09-251-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | Each memory block spans the same amount of sections/pages/bytes. The size is determined before the first memory block is created. No need to store what we can easily calculate - and the calculations even look simpler now. Michal brought up the idea of variable-sized memory blocks. However, if we ever implement something like this, we will need an API compatibility switch and reworks at various places (most code assumes a fixed memory block size). So let's cleanup what we have right now. While at it, fix the variable naming in register_mem_sect_under_node() - we no longer talk about a single section. Link: http://lkml.kernel.org/r/20190809110200.2746-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* driver/base/memory.c: validate memory block size earlyDavid Hildenbrand2019-09-251-22/+9
| | | | | | | | | | | | | | | | | | | | | | | | | Let's validate the memory block size early, when initializing the memory device infrastructure. Fail hard in case the value is not suitable. As nobody checks the return value of memory_dev_init(), turn it into a void function and fail with a panic in all scenarios instead. Otherwise, we'll crash later during boot when core/drivers expect that the memory device infrastructure (including memory_block_size_bytes()) works as expected. I think long term, we should move the whole memory block size configuration (set_memory_block_size_order() and memory_block_size_bytes()) into drivers/base/memory.c. Link: http://lkml.kernel.org/r/20190806090142.22709-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/base/memory.c: fixup documentation of ↵David Hildenbrand2019-09-251-5/+6
| | | | | | | | | | | | | | | | | removable/phys_index/block_size_bytes Let's rephrase to memory block terminology and add some further clarifications. Link: http://lkml.kernel.org/r/20190806080826.5963-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/base/node.c: simplify unregister_memory_block_under_nodes()David Hildenbrand2019-09-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | We don't allow to offline memory block devices that belong to multiple numa nodes. Therefore, such devices can never get removed. It is sufficient to process a single node when removing the memory block. No need to iterate over each and every PFN. We already have the nid stored for each memory block. Make sure that the nid always has a sane value. Please note that checking for node_online(nid) is not required. If we would have a memory block belonging to a node that is no longer offline, then we would have a BUG in the node offlining code. Link: http://lkml.kernel.org/r/20190719135244.15242-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/base/memory.c: get rid of find_memory_block_hinted()David Hildenbrand2019-07-191-26/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | No longer needed, let's remove it. Also, drop the "hint" parameter completely from "find_memory_block_by_id", as nobody needs it anymore. [david@redhat.com: v3] Link: http://lkml.kernel.org/r/20190620183139.4352-7-david@redhat.com [david@redhat.com: handle zero-length walks] Link: http://lkml.kernel.org/r/1c2edc22-afd7-2211-c4c7-40e54e5007e8@redhat.com Link: http://lkml.kernel.org/r/20190614100114.311-7-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Qian Cai <cai@lca.pw> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Mike Travis <mike.travis@hpe.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: move and simplify walk_memory_blocks()David Hildenbrand2019-07-191-0/+42
| | | | | | | | | | | | | | | | | | | | | | | | Let's move walk_memory_blocks() to the place where memory block logic resides and simplify it. While at it, add a type for the callback function. Link: http://lkml.kernel.org/r/20190614100114.311-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Mike Travis <mike.travis@hpe.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/base/memory: use "unsigned long" for block idsDavid Hildenbrand2019-07-191-11/+11
| | | | | | | | | | | | | Block ids are just shifted section numbers, so let's also use "unsigned long" for them, too. Link: http://lkml.kernel.org/r/20190614100114.311-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: section numbers use the type "unsigned long"David Hildenbrand2019-07-191-14/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm: Further memory block device cleanups", v1. Some further cleanups around memory block devices. Especially, clean up and simplify walk_memory_range(). Including some other minor cleanups. This patch (of 6): We are using a mixture of "int" and "unsigned long". Let's make this consistent by using "unsigned long" everywhere. We'll do the same with memory block ids next. While at it, turn the "unsigned long i" in removable_show() into an int - sections_per_block is an int. [akpm@linux-foundation.org: s/unsigned long i/unsigned long nr/] [david@redhat.com: v3] Link: http://lkml.kernel.org/r/20190620183139.4352-2-david@redhat.com Link: http://lkml.kernel.org/r/20190614100114.311-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Arun KS <arunks@codeaurora.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: remove memory block devices before arch_remove_memory()David Hildenbrand2019-07-191-19/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let's factor out removing of memory block devices, which is only necessary for memory added via add_memory() and friends that created memory block devices. Remove the devices before calling arch_remove_memory(). This finishes factoring out memory block device handling from arch_add_memory() and arch_remove_memory(). Link: http://lkml.kernel.org/r/20190527111152.16324-10-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Mark Brown <broonie@kernel.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Oscar Salvador <osalvador@suse.de> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Mathieu Malaterre <malat@debian.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Baoquan He <bhe@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Jun Yao <yaojun8558363@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qian Cai <cai@lca.pw> Cc: Rich Felker <dalias@libc.org> Cc: Rob Herring <robh@kernel.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: create memory block devices after arch_add_memory()David Hildenbrand2019-07-191-28/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Only memory to be added to the buddy and to be onlined/offlined by user space using /sys/devices/system/memory/... needs (and should have!) memory block devices. Factor out creation of memory block devices. Create all devices after arch_add_memory() succeeded. We can later drop the want_memblock parameter, because it is now effectively stale. Only after memory block devices have been added, memory can be onlined by user space. This implies, that memory is not visible to user space at all before arch_add_memory() succeeded. While at it - use WARN_ON_ONCE instead of BUG_ON in moved unregister_memory() - introduce find_memory_block_by_id() to search via block id - Use find_memory_block_by_id() in init_memory_block() to catch duplicates Link: http://lkml.kernel.org/r/20190527111152.16324-8-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Mathieu Malaterre <malat@debian.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Baoquan He <bhe@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Jun Yao <yaojun8558363@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Mark Brown <broonie@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Rob Herring <robh@kernel.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: allow arch_remove_memory() without CONFIG_MEMORY_HOTREMOVEDavid Hildenbrand2019-07-191-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to improve error handling while adding memory by allowing to use arch_remove_memory() and __remove_pages() even if CONFIG_MEMORY_HOTREMOVE is not set to e.g., implement something like: arch_add_memory() rc = do_something(); if (rc) { arch_remove_memory(); } We won't get rid of CONFIG_MEMORY_HOTREMOVE for now, as it will require quite some dependencies for memory offlining. Link: http://lkml.kernel.org/r/20190527111152.16324-7-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Mark Brown <broonie@kernel.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Rob Herring <robh@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Qian Cai <cai@lca.pw> Cc: Mathieu Malaterre <malat@debian.org> Cc: Baoquan He <bhe@redhat.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Jun Yao <yaojun8558363@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/base/memory: pass a block_id to init_memory_block()David Hildenbrand2019-07-191-16/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We'll rework hotplug_memory_register() shortly, so it no longer consumes pass a section. [cai@lca.pw: fix a compilation warning] Link: http://lkml.kernel.org/r/1559320186-28337-1-git-send-email-cai@lca.pw Link: http://lkml.kernel.org/r/20190527111152.16324-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arun KS <arunks@codeaurora.org> Cc: Baoquan He <bhe@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Jun Yao <yaojun8558363@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Mark Brown <broonie@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Mathieu Malaterre <malat@debian.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: "mike.travis@hpe.com" <mike.travis@hpe.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Rob Herring <robh@kernel.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: make unregister_memory_section() never failDavid Hildenbrand2019-05-141-11/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Failing while removing memory is mostly ignored and cannot really be handled. Let's treat errors in unregister_memory_section() in a nice way, warning, but continuing. Link: http://lkml.kernel.org/r/20190409100148.24703-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Mike Travis <mike.travis@hpe.com> Cc: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Qian Cai <cai@lca.pw> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Mathieu Malaterre <malat@debian.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Rob Herring <robh@kernel.org> Cc: Stefan Agner <stefan@agner.ch> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/base/memory.c: clean up relics in function parametersBaoquan He2019-05-141-6/+6
| | | | | | | | | | | | | | | | | | | The input parameter 'phys_index' of memory_block_action() is actually the section number, but not the phys_index of memory_block. This is a relic from the past when one memory block could only contain one section. Rename it to start_section_nr. And also in remove_memory_section(), the 'node_id' and 'phys_device' arguments are not used by anyone. Remove them. Link: http://lkml.kernel.org/r/20190329144250.14315-2-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Mukesh Ojha <mojha@codeaurora.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: do not unlock after failing to take the device_hotplug_lockzhong jiang2019-04-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | When adding memory by probing a memory block in the sysfs interface, there is an obvious issue where we will unlock the device_hotplug_lock when we failed to takes it. That issue was introduced in 8df1d0e4a265 ("mm/memory_hotplug: make add_memory() take the device_hotplug_lock"). We should drop out in time when failing to take the device_hotplug_lock. Link: http://lkml.kernel.org/r/1554696437-9593-1-git-send-email-zhongjiang@huawei.com Fixes: 8df1d0e4a265 ("mm/memory_hotplug: make add_memory() take the device_hotplug_lock") Signed-off-by: zhong jiang <zhongjiang@huawei.com> Reported-by: Yang yingliang <yangyingliang@huawei.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* device-dax: "Hotplug" persistent memory for use like normal RAMDave Hansen2019-02-281-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is intended for use with NVDIMMs that are physically persistent (physically like flash) so that they can be used as a cost-effective RAM replacement. Intel Optane DC persistent memory is one implementation of this kind of NVDIMM. Currently, a persistent memory region is "owned" by a device driver, either the "Direct DAX" or "Filesystem DAX" drivers. These drivers allow applications to explicitly use persistent memory, generally by being modified to use special, new libraries. (DIMM-based persistent memory hardware/software is described in great detail here: Documentation/nvdimm/nvdimm.txt). However, this limits persistent memory use to applications which *have* been modified. To make it more broadly usable, this driver "hotplugs" memory into the kernel, to be managed and used just like normal RAM would be. To make this work, management software must remove the device from being controlled by the "Device DAX" infrastructure: echo dax0.0 > /sys/bus/dax/drivers/device_dax/unbind and then tell the new driver that it can bind to the device: echo dax0.0 > /sys/bus/dax/drivers/kmem/new_id After this, there will be a number of new memory sections visible in sysfs that can be onlined, or that may get onlined by existing udev-initiated memory hotplug rules. This rebinding procedure is currently a one-way trip. Once memory is bound to "kmem", it's there permanently and can not be unbound and assigned back to device_dax. The kmem driver will never bind to a dax device unless the device is *explicitly* bound to the driver. There are two reasons for this: One, since it is a one-way trip, it can not be undone if bound incorrectly. Two, the kmem driver destroys data on the device. Think of if you had good data on a pmem device. It would be catastrophic if you compile-in "kmem", but leave out the "device_dax" driver. kmem would take over the device and write volatile data all over your good data. This inherits any existing NUMA information for the newly-added memory from the persistent memory device that came from the firmware. On Intel platforms, the firmware has guarantees that require each socket's persistent memory to be in a separate memory-only NUMA node. That means that this patch is not expected to create NUMA nodes, but will simply hotplug memory into existing nodes. Because NUMA nodes are created, the existing NUMA APIs and tools are sufficient to create policies for applications or memory areas to have affinity for or an aversion to using this memory. There is currently some metadata at the beginning of pmem regions. The section-size memory hotplug restrictions, plus this small reserved area can cause the "loss" of a section or two of capacity. This should be fixable in follow-on patches. But, as a first step, losing 256MB of memory (worst case) out of hundreds of gigabytes is a good tradeoff vs. the required code to fix this up precisely. This calculation is also the reason we export memory_block_size_bytes(). Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Huang Ying <ying.huang@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Jerome Glisse <jglisse@redhat.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* Merge tag 'driver-core-4.21-rc1' of ↵Linus Torvalds2018-12-291-44/+37
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the "big" set of driver core patches for 4.21-rc1. It's not really big, just a number of small changes for some reported issues, some documentation updates to hopefully make it harder for people to abuse the driver model, and some other minor cleanups. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: mm, memory_hotplug: update a comment in unregister_memory() component: convert to DEFINE_SHOW_ATTRIBUTE sysfs: Disable lockdep for driver bind/unbind files driver core: Add missing dev->bus->need_parent_lock checks kobject: return error code if writing /sys/.../uevent fails driver core: Move async_synchronize_full call driver core: platform: Respect return code of platform_device_register_full() kref/kobject: Improve documentation drivers/base/memory.c: Use DEVICE_ATTR_RO and friends driver core: Replace simple_strto{l,ul} by kstrtou{l,ul} kernfs: Improve kernfs_notify() poll notification latency kobject: Fix warnings in lib/kobject_uevent.c kobject: drop unnecessary cast "%llu" for u64 driver core: fix comments for device_block_probing() driver core: Replace simple_strtol by kstrtoint
| * mm, memory_hotplug: update a comment in unregister_memory()Dan Carpenter2018-12-201-1/+1
| | | | | | | | | | | | | | | | | | The remove_memory_block() function was renamed to in commit cc292b0b4302 ("drivers/base/memory.c: rename remove_memory_block() to remove_memory_section()"). Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * drivers/base/memory.c: Use DEVICE_ATTR_RO and friendsDavid Hildenbrand2018-12-061-43/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let's use the easier to read (and not mess up) variants: - Use DEVICE_ATTR_RO - Use DEVICE_ATTR_WO - Use DEVICE_ATTR_RW instead of the more generic DEVICE_ATTR() we're using right now. We have to rename most callback functions. By fixing the intendations we can even save some LOCs. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | memory_hotplug: add missing newlines to debugging outputMichal Hocko2018-12-281-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pages_correctly_probed is missing new lines which means that the line is not printed rightaway but it rather waits for additional printks. Add \n to all three messages in pages_correctly_probed. Link: http://lkml.kernel.org/r/20181218162307.10518-1-mhocko@kernel.org Fixes: b77eab7079d9 ("mm/memory_hotplug: optimize probe routine") Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | drivers/base/memory.c: remove an unnecessary check on NR_MEM_SECTIONSWei Yang2018-12-281-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | In cb5e39b8038b ("drivers: base: refactor add_memory_section() to add_memory_block()"), add_memory_block() is introduced, which is only invoked in memory_dev_init(). When combining these two loops in memory_dev_init() and add_memory_block(), they looks like this: for (i = 0; i < NR_MEM_SECTIONS; i += sections_per_block) for (j = i; (j < i + sections_per_block) && j < NR_MEM_SECTIONS; j++) Since it is sure the (i < NR_MEM_SECTIONS) and j sits in its own memory block, the check of (j < NR_MEM_SECTIONS) is not necessary. This patch just removes this check. Link: http://lkml.kernel.org/r/20181123222811.18216-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Seth Jennings <sjenning@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: fix online/offline_pages called w.o. mem_hotplug_lockDavid Hildenbrand2018-10-311-12/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There seem to be some problems as result of 30467e0b3be ("mm, hotplug: fix concurrent memory hot-add deadlock"), which tried to fix a possible lock inversion reported and discussed in [1] due to the two locks a) device_lock() b) mem_hotplug_lock While add_memory() first takes b), followed by a) during bus_probe_device(), onlining of memory from user space first took a), followed by b), exposing a possible deadlock. In [1], and it was decided to not make use of device_hotplug_lock, but rather to enforce a locking order. The problems I spotted related to this: 1. Memory block device attributes: While .state first calls mem_hotplug_begin() and the calls device_online() - which takes device_lock() - .online does no longer call mem_hotplug_begin(), so effectively calls online_pages() without mem_hotplug_lock. 2. device_online() should be called under device_hotplug_lock, however onlining memory during add_memory() does not take care of that. In addition, I think there is also something wrong about the locking in 3. arch/powerpc/platforms/powernv/memtrace.c calls offline_pages() without locks. This was introduced after 30467e0b3be. And skimming over the code, I assume it could need some more care in regards to locking (e.g. device_online() called without device_hotplug_lock. This will be addressed in the following patches. Now that we hold the device_hotplug_lock when - adding memory (e.g. via add_memory()/add_memory_resource()) - removing memory (e.g. via remove_memory()) - device_online()/device_offline() We can move mem_hotplug_lock usage back into online_pages()/offline_pages(). Why is mem_hotplug_lock still needed? Essentially to make get_online_mems()/put_online_mems() be very fast (relying on device_hotplug_lock would be very slow), and to serialize against addition of memory that does not create memory block devices (hmm). [1] http://driverdev.linuxdriverproject.org/pipermail/ driverdev-devel/ 2015-February/065324.html This patch is partly based on a patch by Vitaly Kuznetsov. Link: http://lkml.kernel.org/r/20180925091457.28651-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Rashmica Gupta <rashmica.g@gmail.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com> Cc: Mathieu Malaterre <malat@debian.org> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: make add_memory() take the device_hotplug_lockDavid Hildenbrand2018-10-311-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | add_memory() currently does not take the device_hotplug_lock, however is aleady called under the lock from arch/powerpc/platforms/pseries/hotplug-memory.c drivers/acpi/acpi_memhotplug.c to synchronize against CPU hot-remove and similar. In general, we should hold the device_hotplug_lock when adding memory to synchronize against online/offline request (e.g. from user space) - which already resulted in lock inversions due to device_lock() and mem_hotplug_lock - see 30467e0b3be ("mm, hotplug: fix concurrent memory hot-add deadlock"). add_memory()/add_memory_resource() will create memory block devices, so this really feels like the right thing to do. Holding the device_hotplug_lock makes sure that a memory block device can really only be accessed (e.g. via .online/.state) from user space, once the memory has been fully added to the system. The lock is not held yet in drivers/xen/balloon.c arch/powerpc/platforms/powernv/memtrace.c drivers/s390/char/sclp_cmd.c drivers/hv/hv_balloon.c So, let's either use the locked variants or take the lock. Don't export add_memory_resource(), as it once was exported to be used by XEN, which is never built as a module. If somebody requires it, we also have to export a locked variant (as device_hotplug_lock is never exported). Link: http://lkml.kernel.org/r/20180925091457.28651-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mathieu Malaterre <malat@debian.org> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory_hotplug: fix kernel_panic on offline page processingMikhail Zaslonko2018-09-051-11/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Within show_valid_zones() the function test_pages_in_a_zone() should be called for online memory blocks only. Otherwise it might lead to the VM_BUG_ON due to uninitialized struct pages (when CONFIG_DEBUG_VM_PGFLAGS kernel option is set): page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p)) ------------[ cut here ]------------ Call Trace: ([<000000000038f91e>] test_pages_in_a_zone+0xe6/0x168) [<0000000000923472>] show_valid_zones+0x5a/0x1a8 [<0000000000900284>] dev_attr_show+0x3c/0x78 [<000000000046f6f0>] sysfs_kf_seq_show+0xd0/0x150 [<00000000003ef662>] seq_read+0x212/0x4b8 [<00000000003bf202>] __vfs_read+0x3a/0x178 [<00000000003bf3ca>] vfs_read+0x8a/0x148 [<00000000003bfa3a>] ksys_read+0x62/0xb8 [<0000000000bc2220>] system_call+0xdc/0x2d8 That VM_BUG_ON was triggered by the page poisoning introduced in mm/sparse.c with the git commit d0dc12e86b31 ("mm/memory_hotplug: optimize memory hotplug"). With the same commit the new 'nid' field has been added to the struct memory_block in order to store and later on derive the node id for offline pages (instead of accessing struct page which might be uninitialized). But one reference to nid in show_valid_zones() function has been overlooked. Fixed with current commit. Also, nr_pages will not be used any more after test_pages_in_a_zone() call, do not update it. Link: http://lkml.kernel.org/r/20180828090539.41491-1-zaslonko@linux.ibm.com Fixes: d0dc12e86b31 ("mm/memory_hotplug: optimize memory hotplug") Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: <stable@vger.kernel.org> [4.17+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug.c: call register_mem_sect_under_node()Oscar Salvador2018-08-181-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When hotplugging memory, it is possible that two calls are being made to register_mem_sect_under_node(). One comes from __add_section()->hotplug_memory_register() and the other from add_memory_resource()->link_mem_sections() if we had to register a new node. In case we had to register a new node, hotplug_memory_register() will only handle/allocate the memory_block's since register_mem_sect_under_node() will return right away because the node it is not online yet. I think it is better if we leave hotplug_memory_register() to handle/allocate only memory_block's and make link_mem_sections() to call register_mem_sect_under_node(). So this patch removes the call to register_mem_sect_under_node() from hotplug_memory_register(), and moves the call to link_mem_sections() out of the condition, so it will always be called. In this way we only have one place where the memory sections are registered. Link: http://lkml.kernel.org/r/20180622111839.10071-3-osalvador@techadventures.net Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com> Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com> Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: memory_hotplug: use put_device() if device_register failArvind Yadav2018-05-141-1/+7
| | | | | | | | if device_register() returned an error. Always use put_device() to give up the initialized reference and release allocated memory. Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm: check __highest_present_section_nr directly in memory_dev_init()Wei Yang2018-04-111-5/+2
| | | | | | | | | | | | | | | __highest_present_section_nr is a more strict boundary than NR_MEM_SECTIONS. So checking __highest_present_section_nr directly is enough. Link: http://lkml.kernel.org/r/20180330032044.21647-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: don't read nid from struct page during hotplugPavel Tatashin2018-04-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During memory hotplugging the probe routine will leave struct pages uninitialized, the same as it is currently done during boot. Therefore, we do not want to access the inside of struct pages before __init_single_page() is called during onlining. Because during hotplug we know that pages in one memory block belong to the same numa node, we can skip the checking. We should keep checking for the boot case. [pasha.tatashin@oracle.com: s/register_new_memory()/hotplug_memory_register()] Link: http://lkml.kernel.org/r/20180228030308.1116-6-pasha.tatashin@oracle.com Link: http://lkml.kernel.org/r/20180215165920.8570-6-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Bharata B Rao <bharata@linux.vnet.ibm.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Steven Sistare <steven.sistare@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: optimize probe routinePavel Tatashin2018-04-061-16/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When memory is hotplugged pages_correctly_reserved() is called to verify that the added memory is present, this routine traverses through every struct page and verifies that PageReserved() is set. This is a slow operation especially if a large amount of memory is added. Instead of checking every page, it is enough to simply check that the section is present, has mapping (struct page array is allocated), and the mapping is online. In addition, we should not excpect that probe routine sets flags in struct page, as the struct pages have not yet been initialized. The initialization should be done in __init_single_page(), the same as during boot. Link: http://lkml.kernel.org/r/20180215165920.8570-5-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Bharata B Rao <bharata@linux.vnet.ibm.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Steven Sistare <steven.sistare@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_failure: Remove unused trapno from memory_failureEric W. Biederman2018-01-231-1/+1
| | | | | | | | | Today 4 architectures set ARCH_SUPPORTS_MEMORY_FAILURE (arm64, parisc, powerpc, and x86), while 4 other architectures set __ARCH_SI_TRAPNO (alpha, metag, sparc, and tile). These two sets of architectures do not interesect so remove the trapno paramater to remove confusion. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm, memory_hotplug: remove zone restrictionsMichal Hocko2017-09-071-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Historically we have enforced that any kernel zone (e.g ZONE_NORMAL) has to precede the Movable zone in the physical memory range. The purpose of the movable zone is, however, not bound to any physical memory restriction. It merely defines a class of migrateable and reclaimable memory. There are users (e.g. CMA) who might want to reserve specific physical memory ranges for their own purpose. Moreover our pfn walkers have to be prepared for zones overlapping in the physical range already because we do support interleaving NUMA nodes and therefore zones can interleave as well. This means we can allow each memory block to be associated with a different zone. Loosen the current onlining semantic and allow explicit onlining type on any memblock. That means that online_{kernel,movable} will be allowed regardless of the physical address of the memblock as long as it is offline of course. This might result in moveble zone overlapping with other kernel zones. Default onlining then becomes a bit tricky but still sensible. echo online > memoryXY/state will online the given block to 1) the default zone if the given range is outside of any zone 2) the enclosing zone if such a zone doesn't interleave with any other zone 3) the default zone if more zones interleave for this range where default zone is movable zone only if movable_node is enabled otherwise it is a kernel zone. Here is an example of the semantic with (movable_node is not present but it work in an analogous way). We start with following memblocks, all of them offline: memory34/valid_zones:Normal Movable memory35/valid_zones:Normal Movable memory36/valid_zones:Normal Movable memory37/valid_zones:Normal Movable memory38/valid_zones:Normal Movable memory39/valid_zones:Normal Movable memory40/valid_zones:Normal Movable memory41/valid_zones:Normal Movable Now, we online block 34 in default mode and block 37 as movable root@test1:/sys/devices/system/node/node1# echo online > memory34/state root@test1:/sys/devices/system/node/node1# echo online_movable > memory37/state memory34/valid_zones:Normal memory35/valid_zones:Normal Movable memory36/valid_zones:Normal Movable memory37/valid_zones:Movable memory38/valid_zones:Normal Movable memory39/valid_zones:Normal Movable memory40/valid_zones:Normal Movable memory41/valid_zones:Normal Movable As we can see all other blocks can still be onlined both into Normal and Movable zones and the Normal is default because the Movable zone spans only block37 now. root@test1:/sys/devices/system/node/node1# echo online_movable > memory41/state memory34/valid_zones:Normal memory35/valid_zones:Normal Movable memory36/valid_zones:Normal Movable memory37/valid_zones:Movable memory38/valid_zones:Movable Normal memory39/valid_zones:Movable Normal memory40/valid_zones:Movable Normal memory41/valid_zones:Movable Now the default zone for blocks 37-41 has changed because movable zone spans that range. root@test1:/sys/devices/system/node/node1# echo online_kernel > memory39/state memory34/valid_zones:Normal memory35/valid_zones:Normal Movable memory36/valid_zones:Normal Movable memory37/valid_zones:Movable memory38/valid_zones:Normal Movable memory39/valid_zones:Normal memory40/valid_zones:Movable Normal memory41/valid_zones:Movable Note that the block 39 now belongs to the zone Normal and so block38 falls into Normal by default as well. For completness root@test1:/sys/devices/system/node/node1# for i in memory[34]? do echo online > $i/state 2>/dev/null done memory34/valid_zones:Normal memory35/valid_zones:Normal memory36/valid_zones:Normal memory37/valid_zones:Movable memory38/valid_zones:Normal memory39/valid_zones:Normal memory40/valid_zones:Movable memory41/valid_zones:Movable Implementation wise the change is quite straightforward. We can get rid of allow_online_pfn_range altogether. online_pages allows only offline nodes already. The original default_zone_for_pfn will become default_kernel_zone_for_pfn. New default_zone_for_pfn implements the above semantic. zone_for_pfn_range is slightly reorganized to implement kernel and movable online type explicitly and MMOP_ONLINE_KEEP becomes a catch all default behavior. Link: http://lkml.kernel.org/r/20170714121233.16861-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Kani Toshimitsu <toshi.kani@hpe.com> Cc: <slaoub@gmail.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: <linux-api@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory_hotplug: display allowed zones in the preferred orderingMichal Hocko2017-09-071-10/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prior to commit f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") we used to allow to change the valid zone types of a memory block if it is adjacent to a different zone type. This fact was reflected in memoryNN/valid_zones by the ordering of printed zones. The first one was default (echo online > memoryNN/state) and the other one could be onlined explicitly by online_{movable,kernel}. This behavior was removed by the said patch and as such the ordering was not all that important. In most cases a kernel zone would be default anyway. The only exception is movable_node handled by "mm, memory_hotplug: support movable_node for hotpluggable nodes". Let's reintroduce this behavior again because later patch will remove the zone overlap restriction and so user will be allowed to online kernel resp. movable block regardless of its placement. Original behavior will then become significant again because it would be non-trivial for users to see what is the default zone to online into. Implementation is really simple. Pull out zone selection out of move_pfn_range into zone_for_pfn_range helper and use it in show_valid_zones to display the zone for default onlining and then both kernel and movable if they are allowed. Default online zone is not duplicated. Link: http://lkml.kernel.org/r/20170714121233.16861-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Kani Toshimitsu <toshi.kani@hpe.com> Cc: <slaoub@gmail.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory_hotplug: do not assume ZONE_NORMAL is default kernel zoneMichal Hocko2017-07-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Heiko Carstens has noticed that he can generate overlapping zones for ZONE_DMA and ZONE_NORMAL: DMA [mem 0x0000000000000000-0x000000007fffffff] Normal [mem 0x0000000080000000-0x000000017fffffff] $ cat /sys/devices/system/memory/block_size_bytes 10000000 $ cat /sys/devices/system/memory/memory5/valid_zones DMA $ echo 0 > /sys/devices/system/memory/memory5/online $ cat /sys/devices/system/memory/memory5/valid_zones Normal $ echo 1 > /sys/devices/system/memory/memory5/online Normal $ cat /proc/zoneinfo Node 0, zone DMA spanned 524288 <----- present 458752 managed 455078 start_pfn: 0 <----- Node 0, zone Normal spanned 720896 present 589824 managed 571648 start_pfn: 327680 <----- The reason is that we assume that the default zone for kernel onlining is ZONE_NORMAL. This was a simplification introduced by the memory hotplug rework and it is easily fixable by checking the range overlap in the zone order and considering the first matching zone as the default one. If there is no such zone then assume ZONE_NORMAL as we have been doing so far. Fixes: "mm, memory_hotplug: do not associate hotadded memory to zones until online" Link: http://lkml.kernel.org/r/20170601083746.4924-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory_hotplug: do not associate hotadded memory to zones until onlineMichal Hocko2017-07-071-24/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current memory hotplug implementation relies on having all the struct pages associate with a zone/node during the physical hotplug phase (arch_add_memory->__add_pages->__add_section->__add_zone). In the vast majority of cases this means that they are added to ZONE_NORMAL. This has been so since 9d99aaa31f59 ("[PATCH] x86_64: Support memory hotadd without sparsemem") and it wasn't a big deal back then because movable onlining didn't exist yet. Much later memory hotplug wanted to (ab)use ZONE_MOVABLE for movable onlining 511c2aba8f07 ("mm, memory-hotplug: dynamic configure movable memory and portion memory") and then things got more complicated. Rather than reconsidering the zone association which was no longer needed (because the memory hotplug already depended on SPARSEMEM) a convoluted semantic of zone shifting has been developed. Only the currently last memblock or the one adjacent to the zone_movable can be onlined movable. This essentially means that the online type changes as the new memblocks are added. Let's simulate memory hot online manually $ echo 0x100000000 > /sys/devices/system/memory/probe $ grep . /sys/devices/system/memory/memory32/valid_zones Normal Movable $ echo $((0x100000000+(128<<20))) > /sys/devices/system/memory/probe $ grep . /sys/devices/system/memory/memory3?/valid_zones /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal Movable $ echo $((0x100000000+2*(128<<20))) > /sys/devices/system/memory/probe $ grep . /sys/devices/system/memory/memory3?/valid_zones /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal /sys/devices/system/memory/memory34/valid_zones:Normal Movable $ echo online_movable > /sys/devices/system/memory/memory34/state $ grep . /sys/devices/system/memory/memory3?/valid_zones /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Movable Normal This is an awkward semantic because an udev event is sent as soon as the block is onlined and an udev handler might want to online it based on some policy (e.g. association with a node) but it will inherently race with new blocks showing up. This patch changes the physical online phase to not associate pages with any zone at all. All the pages are just marked reserved and wait for the onlining phase to be associated with the zone as per the online request. There are only two requirements - existing ZONE_NORMAL and ZONE_MOVABLE cannot overlap - ZONE_NORMAL precedes ZONE_MOVABLE in physical addresses the latter one is not an inherent requirement and can be changed in the future. It preserves the current behavior and made the code slightly simpler. This is subject to change in future. This means that the same physical online steps as above will lead to the following state: Normal Movable /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Normal Movable /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Movable Implementation: The current move_pfn_range is reimplemented to check the above requirements (allow_online_pfn_range) and then updates the respective zone (move_pfn_range_to_zone), the pgdat and links all the pages in the pfn range with the zone/node. __add_pages is updated to not require the zone and only initializes sections in the range. This allowed to simplify the arch_add_memory code (s390 could get rid of quite some of code). devm_memremap_pages is the only user of arch_add_memory which relies on the zone association because it only hooks into the memory hotplug only half way. It uses it to associate the new memory with ZONE_DEVICE but doesn't allow it to be {on,off}lined via sysfs. This means that this particular code path has to call move_pfn_range_to_zone explicitly. The original zone shifting code is kept in place and will be removed in the follow up patch for an easier review. Please note that this patch also changes the original behavior when offlining a memory block adjacent to another zone (Normal vs. Movable) used to allow to change its movable type. This will be handled later. [richard.weiyang@gmail.com: simplify zone_intersects()] Link: http://lkml.kernel.org/r/20170616092335.5177-1-richard.weiyang@gmail.com [richard.weiyang@gmail.com: remove duplicate call for set_page_links] Link: http://lkml.kernel.org/r/20170616092335.5177-2-richard.weiyang@gmail.com [akpm@linux-foundation.org: remove unused local `i'] Link: http://lkml.kernel.org/r/20170515085827.16474-12-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # For s390 bits Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory_hotplug: consider offline memblocks removableMichal Hocko2017-07-071-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | is_pageblock_removable_nolock() relies on having zone association to examine all the page blocks to check whether they are movable or free. This is just wasting of cycles when the memblock is offline. Later patch in the series will also change the time when the page is associated with a zone so we let's bail out early if the memblock is offline. Link: http://lkml.kernel.org/r/20170515085827.16474-7-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Igor Mammedov <imammedo@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memory_hotplug: get rid of is_zone_device_sectionMichal Hocko2017-07-071-14/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Device memory hotplug hooks into regular memory hotplug only half way. It needs memory sections to track struct pages but there is no need/desire to associate those sections with memory blocks and export them to the userspace via sysfs because they cannot be onlined anyway. This is currently expressed by for_device argument to arch_add_memory which then makes sure to associate the given memory range with ZONE_DEVICE. register_new_memory then relies on is_zone_device_section to distinguish special memory hotplug from the regular one. While this works now, later patches in this series want to move __add_zone outside of arch_add_memory path so we have to come up with something else. Add want_memblock down the __add_pages path and use it to control whether the section->memblock association should be done. arch_add_memory then just trivially want memblock for everything but for_device hotplug. remove_memory_section doesn't need is_zone_device_section either. We can simply skip all the memblock specific cleanup if there is no memblock for the given section. This shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170515085827.16474-5-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, sparsemem: break out of loops earlyDave Hansen2017-07-071-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a number of times that we loop over NR_MEM_SECTIONS, looking for section_present() on each section. But, when we have very large physical address spaces (large MAX_PHYSMEM_BITS), NR_MEM_SECTIONS becomes very large, making the loops quite long. With MAX_PHYSMEM_BITS=46 and a section size of 128MB, the current loops are 512k iterations, which we barely notice on modern hardware. But, raising MAX_PHYSMEM_BITS higher (like we will see on systems that support 5-level paging) makes this 64x longer and we start to notice, especially on slower systems like simulators. A 10-second delay for 512k iterations is annoying. But, a 640- second delay is crippling. This does not help if we have extremely sparse physical address spaces, but those are quite rare. We expect that most of the "slow" systems where this matters will also be quite small and non-sparse. To fix this, we track the highest section we've ever encountered. This lets us know when we will *never* see another section_present(), and lets us break out of the loops earlier. Doing the whole for_each_present_section_nr() macro is probably overkill, but it will ensure that any future loop iterations that we grow are more likely to be correct. Kirrill said "It shaved almost 40 seconds from boot time in qemu with 5-level paging enabled for me". Link: http://lkml.kernel.org/r/20170504174434.C45A4735@viggo.jf.intel.com Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: use dev_online for memhp_auto_onlineNathan Fontenot2017-02-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 31bc3858ea3e ("add automatic onlining policy for the newly added memory") provides the capability to have added memory automatically onlined during add, but this appears to be slightly broken. The current implementation uses walk_memory_range() to call online_memory_block, which uses memory_block_change_state() to online the memory. Instead, we should be calling device_online() for the memory block in online_memory_block(). This would online the memory (the memory bus online routine memory_subsys_online() called from device_online calls memory_block_change_state()) and properly update the device struct offline flag. As a result of the current implementation, attempting to remove a memory block after adding it using auto online fails. This is because doing a remove, for instance echo offline > /sys/devices/system/memory/memoryXXX/state uses device_offline() which checks the dev->offline flag. Link: http://lkml.kernel.org/r/20170222220744.8119.19687.stgit@ltcalpine2-lp14.aus.stglabs.ibm.com Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* base/memory, hotplug: fix a kernel oops in show_valid_zones()Toshi Kani2017-02-031-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reading a sysfs "memoryN/valid_zones" file leads to the following oops when the first page of a range is not backed by struct page. show_valid_zones() assumes that 'start_pfn' is always valid for page_zone(). BUG: unable to handle kernel paging request at ffffea017a000000 IP: show_valid_zones+0x6f/0x160 This issue may happen on x86-64 systems with 64GiB or more memory since their memory block size is bumped up to 2GiB. [1] An example of such systems is desribed below. 0x3240000000 is only aligned by 1GiB and this memory block starts from 0x3200000000, which is not backed by struct page. BIOS-e820: [mem 0x0000003240000000-0x000000603fffffff] usable Since test_pages_in_a_zone() already checks holes, fix this issue by extending this function to return 'valid_start' and 'valid_end' for a given range. show_valid_zones() then proceeds with the valid range. [1] 'Commit bdee237c0343 ("x86: mm: Use 2GB memory block size on large-memory x86-64 systems")' Link: http://lkml.kernel.org/r/20170127222149.30893-3-toshi.kani@hpe.com Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> [4.4+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory_hotplug: make zone_can_shift() return a boolean valueYasuaki Ishimatsu2017-01-251-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | online_{kernel|movable} is used to change the memory zone to ZONE_{NORMAL|MOVABLE} and online the memory. To check that memory zone can be changed, zone_can_shift() is used. Currently the function returns minus integer value, plus integer value and 0. When the function returns minus or plus integer value, it means that the memory zone can be changed to ZONE_{NORNAL|MOVABLE}. But when the function returns 0, there are two meanings. One of the meanings is that the memory zone does not need to be changed. For example, when memory is in ZONE_NORMAL and onlined by online_kernel the memory zone does not need to be changed. Another meaning is that the memory zone cannot be changed. When memory is in ZONE_NORMAL and onlined by online_movable, the memory zone may not be changed to ZONE_MOVALBE due to memory online limitation(see Documentation/memory-hotplug.txt). In this case, memory must not be onlined. The patch changes the return type of zone_can_shift() so that memory online operation fails when memory zone cannot be changed as follows: Before applying patch: # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 7864320 managed 7864320 # echo online_movable > memory4097/state # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 8388608 managed 8388608 online_movable operation succeeded. But memory is onlined as ZONE_NORMAL, not ZONE_MOVABLE. After applying patch: # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 7864320 managed 7864320 # echo online_movable > memory4097/state bash: echo: write error: Invalid argument # grep -A 35 "Node 2" /proc/zoneinfo Node 2, zone Normal <snip> node_scanned 0 spanned 8388608 present 7864320 managed 7864320 online_movable operation failed because of failure of changing the memory zone from ZONE_NORMAL to ZONE_MOVABLE Fixes: df429ac03936 ("memory-hotplug: more general validation of zone during online") Link: http://lkml.kernel.org/r/2f9c3837-33d7-b6e5-59c0-6ca4372b2d84@gmail.com Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by: Reza Arbab <arbab@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds2016-12-241-1/+1
| | | | | | | | | | | | | This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/base/memory.c: Remove unused 'first_page' variableKirtika Ruchandani2016-11-291-2/+0
| | | | | | | | | | | | | | | | | | | | | | | Commit 71fbd556adde ("memory-hotplug: remove redundant call of page_to_pfn") introduced an optimization that rendered 'struct page* first_page' useless in memory_block_action(). Compiling with W=1 gives the following warning, fix it. drivers/base/memory.c: In function ‘memory_block_action’: drivers/base/memory.c:229:15: warning: variable ‘first_page’ set but not used [-Wunused-but-set-variable] struct page *first_page; ^ This is a harmeless warning and is only being fixed to reduce the noise with W=1 in the kernel. The call to pfn_to_page() has no side effects and is safe to remove. Fixes: 71fbd556adde ("memory-hotplug: remove redundant call of page_to_pfn") Cc: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Kirtika Ruchandani <kirtika@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* memory-hotplug: fix store_mem_state() return valueReza Arbab2016-10-081-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | If store_mem_state() is called to online memory which is already online, it will return 1, the value it got from device_online(). This is wrong because store_mem_state() is a device_attribute .store function. Thus a non-negative return value represents input bytes read. Set the return value to -EINVAL in this case. Link: http://lkml.kernel.org/r/1472743777-24266-1-git-send-email-arbab@linux.vnet.ibm.com Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Chen Yucong <slaoub@gmail.com> Cc: Andrew Banman <abanman@sgi.com> Cc: Seth Jennings <sjenning@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: use zone_can_shift() for sysfs valid_zones attributeReza Arbab2016-07-271-11/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | Since zone_can_shift() is being used to validate the target zone during onlining, it should also be used to determine the content of valid_zones. Link: http://lkml.kernel.org/r/1462816419-4479-4-git-send-email-arbab@linux.vnet.ibm.com Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com> Reviewd-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Andrew Banman <abanman@sgi.com> Cc: Chen Yucong <slaoub@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory-hotplug: add automatic onlining policy for the newly added memoryVitaly Kuznetsov2016-03-161-1/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, all newly added memory blocks remain in 'offline' state unless someone onlines them, some linux distributions carry special udev rules like: SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online" to make this happen automatically. This is not a great solution for virtual machines where memory hotplug is being used to address high memory pressure situations as such onlining is slow and a userspace process doing this (udev) has a chance of being killed by the OOM killer as it will probably require to allocate some memory. Introduce default policy for the newly added memory blocks in /sys/devices/system/memory/auto_online_blocks file with two possible values: "offline" which preserves the current behavior and "online" which causes all newly added memory blocks to go online as soon as they're added. The default is "offline". Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: skip memory block registration for ZONE_DEVICEDan Williams2016-01-161-0/+13
| | | | | | | | | | | | | | | | | | | | Prevent userspace from trying and failing to online ZONE_DEVICE pages which are meant to never be onlined. For example on platforms with a udev rule like the following: SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online" ...will generate futile attempts to online the ZONE_DEVICE sections. Example kernel messages: Built 1 zonelists in Node order, mobility grouping on. Total pages: 1004747 Policy zone: Normal online_pages [mem 0x248000000-0x24fffffff] failed Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>