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* mm/memory_hotplug: add pgprot_t to mhp_paramsLogan Gunthorpe2020-04-112-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | devm_memremap_pages() is currently used by the PCI P2PDMA code to create struct page mappings for IO memory. At present, these mappings are created with PAGE_KERNEL which implies setting the PAT bits to be WB. However, on x86, an mtrr register will typically override this and force the cache type to be UC-. In the case firmware doesn't set this register it is effectively WB and will typically result in a machine check exception when it's accessed. Other arches are not currently likely to function correctly seeing they don't have any MTRR registers to fall back on. To solve this, provide a way to specify the pgprot value explicitly to arch_add_memory(). Of the arches that support MEMORY_HOTPLUG: x86_64, and arm64 need a simple change to pass the pgprot_t down to their respective functions which set up the page tables. For x86_32, set the page tables explicitly using _set_memory_prot() (seeing they are already mapped). For ia64, s390 and sh, reject anything but PAGE_KERNEL settings -- this should be fine, for now, seeing these architectures don't support ZONE_DEVICE. A check in __add_pages() is also added to ensure the pgprot parameter was set for all arches. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Badger <ebadger@gigaio.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Link: http://lkml.kernel.org/r/20200306170846.9333-7-logang@deltatee.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory_hotplug: rename mhp_restrictions to mhp_paramsLogan Gunthorpe2020-04-112-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The mhp_restrictions struct really doesn't specify anything resembling a restriction anymore so rename it to be mhp_params as it is a list of extended parameters. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Badger <ebadger@gigaio.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Link: http://lkml.kernel.org/r/20200306170846.9333-3-logang@deltatee.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/vma: introduce VM_ACCESS_FLAGSAnshuman Khandual2020-04-112-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are many places where all basic VMA access flags (read, write, exec) are initialized or checked against as a group. One such example is during page fault. Existing vma_is_accessible() wrapper already creates the notion of VMA accessibility as a group access permissions. Hence lets just create VM_ACCESS_FLAGS (VM_READ|VM_WRITE|VM_EXEC) which will not only reduce code duplication but also extend the VMA accessibility concept in general. Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Salter <msalter@redhat.com> Cc: Nick Hu <nickhu@andestech.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Rob Springer <rspringer@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Link: http://lkml.kernel.org/r/1583391014-8170-3-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory.c: add vm_insert_pages()Arjun Roy2020-04-111-2/+127
| | | | | | | | | | | | | | | | | | | | | | | | | Add the ability to insert multiple pages at once to a user VM with lower PTE spinlock operations. The intention of this patch-set is to reduce atomic ops for tcp zerocopy receives, which normally hits the same spinlock multiple times consecutively. [akpm@linux-foundation.org: pte_alloc() no longer takes the `addr' argument] [arjunroy@google.com: add missing page_count() check to vm_insert_pages()] Link: http://lkml.kernel.org/r/20200214005929.104481-1-arjunroy.kdev@gmail.com [arjunroy@google.com: vm_insert_pages() checks if pte_index defined] Link: http://lkml.kernel.org/r/20200228054714.204424-2-arjunroy.kdev@gmail.com Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Miller <davem@davemloft.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: http://lkml.kernel.org/r/20200128025958.43490-2-arjunroy.kdev@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/memory.c: refactor insert_page to prepare for batched-lock insertArjun Roy2020-04-111-15/+24
| | | | | | | | | | | | | | | | | | | | | | Add helper methods for vm_insert_page()/insert_page() to prepare for vm_insert_pages(), which batch-inserts pages to reduce spinlock operations when inserting multiple consecutive pages into the user page table. The intention of this patch-set is to reduce atomic ops for tcp zerocopy receives, which normally hits the same spinlock multiple times consecutively. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Miller <davem@davemloft.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: http://lkml.kernel.org/r/20200128025958.43490-1-arjunroy.kdev@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/mmap.c: initialize align_offset explicitly for vm_unmapped_areaJaewon Kim2020-04-111-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | On passing requirement to vm_unmapped_area, arch_get_unmapped_area and arch_get_unmapped_area_topdown did not set align_offset. Internally on both unmapped_area and unmapped_area_topdown, if info->align_mask is 0, then info->align_offset was meaningless. But commit df529cabb7a2 ("mm: mmap: add trace point of vm_unmapped_area") always prints info->align_offset even though it is uninitialized. Fix this uninitialized value issue by setting it to 0 explicitly. Before: vm_unmapped_area: addr=0x755b155000 err=0 total_vm=0x15aaf0 flags=0x1 len=0x109000 lo=0x8000 hi=0x75eed48000 mask=0x0 ofs=0x4022 After: vm_unmapped_area: addr=0x74a4ca1000 err=0 total_vm=0x168ab1 flags=0x1 len=0x9000 lo=0x8000 hi=0x753d94b000 mask=0x0 ofs=0x0 Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michel Lespinasse <walken@google.com> Cc: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/20200409094035.19457-1-jaewon31.kim@samsung.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: hugetlb: optionally allocate gigantic hugepages using cmaRoman Gushchin2020-04-111-0/+109
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 944d9fec8d7a ("hugetlb: add support for gigantic page allocation at runtime") has added the run-time allocation of gigantic pages. However it actually works only at early stages of the system loading, when the majority of memory is free. After some time the memory gets fragmented by non-movable pages, so the chances to find a contiguous 1GB block are getting close to zero. Even dropping caches manually doesn't help a lot. At large scale rebooting servers in order to allocate gigantic hugepages is quite expensive and complex. At the same time keeping some constant percentage of memory in reserved hugepages even if the workload isn't using it is a big waste: not all workloads can benefit from using 1 GB pages. The following solution can solve the problem: 1) On boot time a dedicated cma area* is reserved. The size is passed as a kernel argument. 2) Run-time allocations of gigantic hugepages are performed using the cma allocator and the dedicated cma area In this case gigantic hugepages can be allocated successfully with a high probability, however the memory isn't completely wasted if nobody is using 1GB hugepages: it can be used for pagecache, anon memory, THPs, etc. * On a multi-node machine a per-node cma area is allocated on each node. Following gigantic hugetlb allocation are using the first available numa node if the mask isn't specified by a user. Usage: 1) configure the kernel to allocate a cma area for hugetlb allocations: pass hugetlb_cma=10G as a kernel argument 2) allocate hugetlb pages as usual, e.g. echo 10 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages If the option isn't enabled or the allocation of the cma area failed, the current behavior of the system is preserved. x86 and arm-64 are covered by this patch, other architectures can be trivially added later. The patch contains clean-ups and fixes proposed and implemented by Aslan Bakirov and Randy Dunlap. It also contains ideas and suggestions proposed by Rik van Riel, Michal Hocko and Mike Kravetz. Thanks! Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Andreas Schaufler <andreas.schaufler@gmx.de> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michal Hocko <mhocko@kernel.org> Cc: Aslan Bakirov <aslan@fb.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Joonsoo Kim <js1304@gmail.com> Link: http://lkml.kernel.org/r/20200407163840.92263-3-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: cma: NUMA node interfaceAslan Bakirov2020-04-112-8/+10
| | | | | | | | | | | | | | | | | | | | | | | | I've noticed that there is no interface exposed by CMA which would let me to declare contigous memory on particular NUMA node. This patchset adds the ability to try to allocate contiguous memory on a specific node. It will fallback to other nodes if the specified one doesn't work. Implement a new method for declaring contigous memory on particular node and keep cma_declare_contiguous() as a wrapper. [akpm@linux-foundation.org: build fix] Signed-off-by: Aslan Bakirov <aslan@fb.com> Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@kernel.org> Cc: Andreas Schaufler <andreas.schaufler@gmx.de> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Rik van Riel <riel@surriel.com> Cc: Joonsoo Kim <js1304@gmail.com> Link: http://lkml.kernel.org/r/20200407163840.92263-2-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/page_alloc: make pcpu_drain_mutex and pcpu_drain staticJason Yan2020-04-111-2/+2
| | | | | | | | | | | | | Fix the following sparse warning: mm/page_alloc.c:106:1: warning: symbol 'pcpu_drain_mutex' was not declared. Should it be static? mm/page_alloc.c:107:1: warning: symbol '__pcpu_scope_pcpu_drain' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200407023925.46438-1-yanaijie@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/page_alloc.c: fix kernel-doc warningRandy Dunlap2020-04-111-0/+1
| | | | | | | | | | | | Add description of function parameter 'mt' to fix kernel-doc warning: mm/page_alloc.c:3246: warning: Function parameter or member 'mt' not described in '__putback_isolated_page' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Link: http://lkml.kernel.org/r/02998bd4-0b82-2f15-2570-f86130304d1e@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, slab_common: fix a typo in comment "eariler"->"earlier"Qiujun Huang2020-04-111-1/+1
| | | | | | | | | | | | There is a typo in comment, fix it. s/eariler/earlier/ Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Christoph Lameter <cl@linux.com> Link: http://lkml.kernel.org/r/20200405160544.1246-1-hqjagain@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, memcg: do not high throttle allocators based on wraparoundJakub Kicinski2020-04-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a cgroup violates its memory.high constraints, we may end up unduly penalising it. For example, for the following hierarchy: A: max high, 20 usage A/B: 9 high, 10 usage A/C: max high, 10 usage We would end up doing the following calculation below when calculating high delay for A/B: A/B: 10 - 9 = 1... A: 20 - PAGE_COUNTER_MAX = 21, so set max_overage to 21. This gets worse with higher disparities in usage in the parent. I have no idea how this disappeared from the final version of the patch, but it is certainly Not Good(tm). This wasn't obvious in testing because, for a simple cgroup hierarchy with only one child, the result is usually roughly the same. It's only in more complex hierarchies that things go really awry (although still, the effects are limited to a maximum of 2 seconds in schedule_timeout_killable at a maximum). [chris@chrisdown.name: changelog] Fixes: e26733e0d0ec ("mm, memcg: throttle allocators based on ancestral memory.high") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Chris Down <chris@chrisdown.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [5.4.x] Link: http://lkml.kernel.org/r/20200331152424.GA1019937@chrisdown.name Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'libnvdimm-for-5.7' of ↵Linus Torvalds2020-04-093-0/+54
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm and dax updates from Dan Williams: "There were multiple touches outside of drivers/nvdimm/ this round to add cross arch compatibility to the devm_memremap_pages() interface, enhance numa information for persistent memory ranges, and add a zero_page_range() dax operation. This cycle I switched from the patchwork api to Konstantin's b4 script for collecting tags (from x86, PowerPC, filesystem, and device-mapper folks), and everything looks to have gone ok there. This has all appeared in -next with no reported issues. Summary: - Add support for region alignment configuration and enforcement to fix compatibility across architectures and PowerPC page size configurations. - Introduce 'zero_page_range' as a dax operation. This facilitates filesystem-dax operation without a block-device. - Introduce phys_to_target_node() to facilitate drivers that want to know resulting numa node if a given reserved address range was onlined. - Advertise a persistence-domain for of_pmem and papr_scm. The persistence domain indicates where cpu-store cycles need to reach in the platform-memory subsystem before the platform will consider them power-fail protected. - Promote numa_map_to_online_node() to a cross-kernel generic facility. - Save x86 numa information to allow for node-id lookups for reserved memory ranges, deploy that capability for the e820-pmem driver. - Pick up some miscellaneous minor fixes, that missed v5.6-final, including a some smatch reports in the ioctl path and some unit test compilation fixups. - Fixup some flexible-array declarations" * tag 'libnvdimm-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (29 commits) dax: Move mandatory ->zero_page_range() check in alloc_dax() dax,iomap: Add helper dax_iomap_zero() to zero a range dax: Use new dax zero page method for zeroing a page dm,dax: Add dax zero_page_range operation s390,dcssblk,dax: Add dax zero_page_range operation to dcssblk driver dax, pmem: Add a dax operation zero_page_range pmem: Add functions for reading/writing page to/from pmem libnvdimm: Update persistence domain value for of_pmem and papr_scm device tools/test/nvdimm: Fix out of tree build libnvdimm/region: Fix build error libnvdimm/region: Replace zero-length array with flexible-array member libnvdimm/label: Replace zero-length array with flexible-array member ACPI: NFIT: Replace zero-length array with flexible-array member libnvdimm/region: Introduce an 'align' attribute libnvdimm/region: Introduce NDD_LABELING libnvdimm/namespace: Enforce memremap_compat_align() libnvdimm/pfn: Prevent raw mode fallback if pfn-infoblock valid libnvdimm: Out of bounds read in __nd_ioctl() acpi/nfit: improve bounds checking for 'func' mm/memremap_pages: Introduce memremap_compat_align() ...
| * Merge branch 'for-5.7/numa' into libnvdimm-for-nextDan Williams2020-04-032-0/+31
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Promote numa_map_to_online_node() to a cross-kernel generic facility. - Save x86 numa information to allow for node-id lookups for reserved memory ranges, deploy that capability for the e820-pmem driver. - Introduce phys_to_target_node() to facilitate drivers that want to know resulting numa node if a given reserved address range was onlined.
| | * x86/mm: Introduce CONFIG_NUMA_KEEP_MEMINFODan Williams2020-02-171-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently x86 numa_meminfo is marked __initdata in the CONFIG_MEMORY_HOTPLUG=n case. In support of a new facility to allow drivers to map reserved memory to a 'target_node' (phys_to_target_node()), add support for removing the __initdata designation for those users. Both memory hotplug and phys_to_target_node() users select CONFIG_NUMA_KEEP_MEMINFO to tell the arch to maintain its physical address to NUMA mapping infrastructure post init. 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: <x86@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Hildenbrand <david@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/158188326422.894464.15742054998046628934.stgit@dwillia2-desk3.amr.corp.intel.com
| | * mm/numa: Skip NUMA_NO_NODE and online nodes in numa_map_to_online_node()Dan Williams2020-02-171-12/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update numa_map_to_online_node() to stop falling back to numa node 0 when the input is NUMA_NO_NODE. Also, skip the lookup if @node is online. This makes the routine compatible with other arch node mapping routines. Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/157401275716.43284.13185549705765009174.stgit@dwillia2-desk3.amr.corp.intel.com Reviewed-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/158188325316.894464.15650888748083329531.stgit@dwillia2-desk3.amr.corp.intel.com
| | * ACPI: NUMA: Up-level "map to online node" functionalityDan Williams2020-02-171-0/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The acpi_map_pxm_to_online_node() helper is used to find the closest online node to a given proximity domain. This is used to map devices in a proximity domain with no online memory or cpus to the closest online node and populate a device's 'numa_node' property. The numa_node property allows applications to be migrated "close" to a resource. In preparation for providing a generic facility to optionally map an address range to its closest online node, or the node the range would represent were it to be onlined (target_node), up-level the core of acpi_map_pxm_to_online_node() to a generic mm/numa helper. Cc: Michal Hocko <mhocko@suse.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/158188324802.894464.13128795207831894206.stgit@dwillia2-desk3.amr.corp.intel.com
| * | mm/memremap_pages: Introduce memremap_compat_align()Dan Williams2020-02-211-0/+23
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "sub-section memory hotplug" facility allows memremap_pages() users like libnvdimm to compensate for hardware platforms like x86 that have a section size larger than their hardware memory mapping granularity. The compensation that sub-section support affords is being tolerant of physical memory resources shifting by units smaller (64MiB on x86) than the memory-hotplug section size (128 MiB). Where the platform physical-memory mapping granularity is limited by the number and capability of address-decode-registers in the memory controller. While the sub-section support allows memremap_pages() to operate on sub-section (2MiB) granularity, the Power architecture may still require 16MiB alignment on "!radix_enabled()" platforms. In order for libnvdimm to be able to detect and manage this per-arch limitation, introduce memremap_compat_align() as a common minimum alignment across all driver-facing memory-mapping interfaces, and let Power override it to 16MiB in the "!radix_enabled()" case. The assumption / requirement for 16MiB to be a viable memremap_compat_align() value is that Power does not have platforms where its equivalent of address-decode-registers never hardware remaps a persistent memory resource on smaller than 16MiB boundaries. Note that I tried my best to not add a new Kconfig symbol, but header include entanglements defeated the #ifndef memremap_compat_align design pattern and the need to export it defeats the __weak design pattern for arch overrides. Based on an initial patch by Aneesh. Link: http://lore.kernel.org/r/CAPcyv4gBGNP95APYaBcsocEa50tQj9b5h__83vgngjq3ouGX_Q@mail.gmail.com Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reported-by: Jeff Moyer <jmoyer@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | mm/gup: Let __get_user_pages_locked() return -EINTR for fatal signalHillf Danton2020-04-081-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __get_user_pages_locked() will return 0 instead of -EINTR after commit 4426e945df588 ("mm/gup: allow VM_FAULT_RETRY for multiple times") which added extra code to allow gup detect fatal signal faster. Restore the original -EINTR behavior. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Fixes: 4426e945df58 ("mm/gup: allow VM_FAULT_RETRY for multiple times") Reported-by: syzbot+3be1a33f04dc782e9fd5@syzkaller.appspotmail.com Signed-off-by: Hillf Danton <hdanton@sina.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/gup: Mark lock taken only after a successful retakePeter Xu2020-04-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | It's definitely incorrect to mark the lock as taken even if down_read_killable() failed. This wass overlooked when we switched from down_read() to down_read_killable() because down_read() won't fail while down_read_killable() could. Fixes: 71335f37c5e8 ("mm/gup: allow to react to fatal signals") Reported-by: syzbot+a8c70b7f3579fc0587dc@syzkaller.appspotmail.com Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/mempolicy: Allow lookup_node() to handle fatal signalPeter Xu2020-04-081-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | lookup_node() uses gup to pin the page and get node information. It checks against ret>=0 assuming the page will be filled in. However it's also possible that gup will return zero, for example, when the thread is quickly killed with a fatal signal. Teach lookup_node() to gracefully return an error -EFAULT if it happens. Meanwhile, initialize "page" to NULL to avoid potential risk of exploiting the pointer. Fixes: 4426e945df58 ("mm/gup: allow VM_FAULT_RETRY for multiple times") Reported-by: syzbot+693dc11fcb53120b5559@syzkaller.appspotmail.com Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | kasan: unset panic_on_warn before calling panic()Kees Cook2020-04-071-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As done in the full WARN() handler, panic_on_warn needs to be cleared before calling panic() to avoid recursive panics. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Elena Petrova <lenaptr@google.com> Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Link: http://lkml.kernel.org/r/20200227193516.32566-6-keescook@chromium.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | kasan: stackdepot: move filter_irq_stacks() to stackdepot.cAlexander Potapenko2020-04-071-23/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | filter_irq_stacks() can be used by other tools (e.g. KMSAN), so it needs to be moved to a common location. lib/stackdepot.c seems a good place, as filter_irq_stacks() is usually applied to the output of stack_trace_save(). This patch has been previously mailed as part of KMSAN RFC patch series. [glider@google.co: nds32: linker script: add SOFTIRQENTRY_TEXT\ Link: http://lkml.kernel.org/r/20200311121002.241430-1-glider@google.com [glider@google.com: add IRQENTRY_TEXT and SOFTIRQENTRY_TEXT to linker script] Link: http://lkml.kernel.org/r/20200311121124.243352-1-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Link: http://lkml.kernel.org/r/20200220141916.55455-3-glider@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc: faster open/read/close with "permanent" filesAlexey Dobriyan2020-04-072-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that "struct proc_ops" exist we can start putting there stuff which could not fly with VFS "struct file_operations"... Most of fs/proc/inode.c file is dedicated to make open/read/.../close reliable in the event of disappearing /proc entries which usually happens if module is getting removed. Files like /proc/cpuinfo which never disappear simply do not need such protection. Save 2 atomic ops, 1 allocation, 1 free per open/read/close sequence for such "permanent" files. Enable "permanent" flag for /proc/cpuinfo /proc/kmsg /proc/modules /proc/slabinfo /proc/stat /proc/sysvipc/* /proc/swaps More will come once I figure out foolproof way to prevent out module authors from marking their stuff "permanent" for performance reasons when it is not. This should help with scalability: benchmark is "read /proc/cpuinfo R times by N threads scattered over the system". N R t, s (before) t, s (after) ----------------------------------------------------- 64 4096 1.582458 1.530502 -3.2% 256 4096 6.371926 6.125168 -3.9% 1024 4096 25.64888 24.47528 -4.6% Benchmark source: #include <chrono> #include <iostream> #include <thread> #include <vector> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> const int NR_CPUS = sysconf(_SC_NPROCESSORS_ONLN); int N; const char *filename; int R; int xxx = 0; int glue(int n) { cpu_set_t m; CPU_ZERO(&m); CPU_SET(n, &m); return sched_setaffinity(0, sizeof(cpu_set_t), &m); } void f(int n) { glue(n % NR_CPUS); while (*(volatile int *)&xxx == 0) { } for (int i = 0; i < R; i++) { int fd = open(filename, O_RDONLY); char buf[4096]; ssize_t rv = read(fd, buf, sizeof(buf)); asm volatile ("" :: "g" (rv)); close(fd); } } int main(int argc, char *argv[]) { if (argc < 4) { std::cerr << "usage: " << argv[0] << ' ' << "N /proc/filename R "; return 1; } N = atoi(argv[1]); filename = argv[2]; R = atoi(argv[3]); for (int i = 0; i < NR_CPUS; i++) { if (glue(i) == 0) break; } std::vector<std::thread> T; T.reserve(N); for (int i = 0; i < N; i++) { T.emplace_back(f, i); } auto t0 = std::chrono::system_clock::now(); { *(volatile int *)&xxx = 1; for (auto& t: T) { t.join(); } } auto t1 = std::chrono::system_clock::now(); std::chrono::duration<double> dt = t1 - t0; std::cout << dt.count() << ' '; return 0; } P.S.: Explicit randomization marker is added because adding non-function pointer will silently disable structure layout randomization. [akpm@linux-foundation.org: coding style fixes] Reported-by: kbuild test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Joe Perches <joe@perches.com> Link: http://lkml.kernel.org/r/20200222201539.GA22576@avx2 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/dmapool.c: micro-optimisation remove unnecessary branchMateusz Nosek2020-04-071-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously there was a check if 'size' is aligned to 'align' and if not then it was aligned. This check was expensive as both branch and division are expensive instructions in most architectures. 'ALIGN' function on already aligned value will not change it, and as it is cheaper than branch + division it can be executed all the time and branch can be removed. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200320173317.26408-1-mateusznosek0@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: use fallthrough;Joe Perches2020-04-079-16/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the various /* fallthrough */ comments to the pseudo-keyword fallthrough; Done via script: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/ Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Link: http://lkml.kernel.org/r/f62fea5d10eb0ccfc05d87c242a620c261219b66.camel@perches.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/mm_init.c: clean code. Use BUILD_BUG_ON when comparing compile time constantMateusz Nosek2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | MAX_ZONELISTS is a compile time constant, so it should be compared using BUILD_BUG_ON not BUG_ON. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Link: http://lkml.kernel.org/r/20200228224617.11343-1-mateusznosek0@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: fix ambiguous comments for better code readabilitychenqiwu2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The parameter of remap_pfn_range() @pfn passed from the caller is actually a page-frame number converted by corresponding physical address of kernel memory, the original comment is ambiguous that may mislead the users. Meanwhile, there is an ambiguous typo "VMM" in the comment of vm_area_struct. So fixing them will make the code more readable. Signed-off-by: chenqiwu <chenqiwu@xiaomi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1583026921-15279-1-git-send-email-qiwuchen55@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/zsmalloc: add missing annotation for unpin_tag()Jules Irenge2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparse reports a warning at unpin_tag()() warning: context imbalance in unpin_tag() - unexpected unlock The root cause is the missing annotation at unpin_tag() Add the missing __releases(bitlock) annotation Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Minchan Kim <minchan@kernel.org> Link: http://lkml.kernel.org/r/20200214204741.94112-14-jbi.octave@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/zsmalloc: add missing annotation for pin_tag()Jules Irenge2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparse reports a warning at pin_tag()() warning: context imbalance in pin_tag() - wrong count at exit The root cause is the missing annotation at pin_tag() Add the missing __acquires(bitlock) annotation Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Minchan Kim <minchan@kernel.org> Link: http://lkml.kernel.org/r/20200214204741.94112-13-jbi.octave@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/zsmalloc: add missing annotation for migrate_read_unlock()Jules Irenge2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparse reports a warning at migrate_read_unlock()() warning: context imbalance in migrate_read_unlock() - unexpected unlock The root cause is the missing annotation at migrate_read_unlock() Add the missing __releases(&zspage->lock) annotation Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Minchan Kim <minchan@kernel.org> Link: http://lkml.kernel.org/r/20200214204741.94112-12-jbi.octave@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/zsmalloc: add missing annotation for migrate_read_lock()Jules Irenge2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparse reports a warning at migrate_read_lock()() warning: context imbalance in migrate_read_lock() - wrong count at exit The root cause is the missing annotation at migrate_read_lock() Add the missing __acquires(&zspage->lock) annotation Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Minchan Kim <minchan@kernel.org> Link: http://lkml.kernel.org/r/20200214204741.94112-11-jbi.octave@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/slub: add missing annotation for put_map()Jules Irenge2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparse reports a warning at put_map()() warning: context imbalance in put_map() - unexpected unlock The root cause is the missing annotation at put_map() Add the missing __releases(&object_map_lock) annotation Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200214204741.94112-10-jbi.octave@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/slub: add missing annotation for get_map()Jules Irenge2020-04-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparse reports a warning at get_map()() warning: context imbalance in get_map() - wrong count at exit The root cause is the missing annotation at get_map() Add the missing __acquires(&object_map_lock) annotation Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200214204741.94112-9-jbi.octave@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/mempolicy: add missing annotation for queue_pages_pmd()Jules Irenge2020-04-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparse reports a warning at queue_pages_pmd() context imbalance in queue_pages_pmd() - unexpected unlock The root cause is the missing annotation at queue_pages_pmd() Add the missing __releases(ptl) Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200214204741.94112-8-jbi.octave@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/hugetlb: add missing annotation for gather_surplus_pages()Jules Irenge2020-04-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparse reports a warning at gather_surplus_pages() warning: context imbalance in hugetlb_cow() - unexpected unlock The root cause is the missing annotation at gather_surplus_pages() Add the missing __must_hold(&hugetlb_lock) Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Link: http://lkml.kernel.org/r/20200214204741.94112-7-jbi.octave@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/compaction: add missing annotation for compact_lock_irqsaveJules Irenge2020-04-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparse reports a warning at compact_lock_irqsave() warning: context imbalance in compact_lock_irqsave() - wrong count at exit The root cause is the missing annotation at compact_lock_irqsave() Add the missing __acquires(lock) annotation. Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200214204741.94112-6-jbi.octave@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/zswap: allow setting default status, compressor and allocator in KconfigMaciej S. Szmigiero2020-04-072-13/+129
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The compressed cache for swap pages (zswap) currently needs from 1 to 3 extra kernel command line parameters in order to make it work: it has to be enabled by adding a "zswap.enabled=1" command line parameter and if one wants a different compressor or pool allocator than the default lzo / zbud combination then these choices also need to be specified on the kernel command line in additional parameters. Using a different compressor and allocator for zswap is actually pretty common as guides often recommend using the lz4 / z3fold pair instead of the default one. In such case it is also necessary to remember to enable the appropriate compression algorithm and pool allocator in the kernel config manually. Let's avoid the need for adding these kernel command line parameters and automatically pull in the dependencies for the selected compressor algorithm and pool allocator by adding an appropriate default switches to Kconfig. The default values for these options match what the code was using previously as its defaults. Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vitaly Wool <vitaly.wool@konsulko.com> Link: http://lkml.kernel.org/r/20200202000112.456103-1-mail@maciej.szmigiero.name Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: prevent a warning when casting void* -> enumPalmer Dabbelt2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | I recently build the RISC-V port with LLVM trunk, which has introduced a new warning when casting from a pointer to an enum of a smaller size. This patch simply casts to a long in the middle to stop the warning. I'd be surprised this is the only one in the kernel, but it's the only one I saw. Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200227211741.83165-1-palmer@dabbelt.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: huge tmpfs: try to split_huge_page() when punching holeHugh Dickins2020-04-073-56/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Yang Shi writes: Currently, when truncating a shmem file, if the range is partly in a THP (start or end is in the middle of THP), the pages actually will just get cleared rather than being freed, unless the range covers the whole THP. Even though all the subpages are truncated (randomly or sequentially), the THP may still be kept in page cache. This might be fine for some usecases which prefer preserving THP, but balloon inflation is handled in base page size. So when using shmem THP as memory backend, QEMU inflation actually doesn't work as expected since it doesn't free memory. But the inflation usecase really needs to get the memory freed. (Anonymous THP will also not get freed right away, but will be freed eventually when all subpages are unmapped: whereas shmem THP still stays in page cache.) Split THP right away when doing partial hole punch, and if split fails just clear the page so that read of the punched area will return zeroes. Hugh Dickins adds: Our earlier "team of pages" huge tmpfs implementation worked in the way that Yang Shi proposes; and we have been using this patch to continue to split the huge page when hole-punched or truncated, since converting over to the compound page implementation. Although huge tmpfs gives out huge pages when available, if the user specifically asks to truncate or punch a hole (perhaps to free memory, perhaps to reduce the memcg charge), then the filesystem should do so as best it can, splitting the huge page. That is not always possible: any additional reference to the huge page prevents split_huge_page() from succeeding, so the result can be flaky. But in practice it works successfully enough that we've not seen any problem from that. Add shmem_punch_compound() to encapsulate the decision of when a split is needed, and doing the split if so. Using this simplifies the flow in shmem_undo_range(); and the first (trylock) pass does not need to do any page clearing on failure, because the second pass will either succeed or do that clearing. Following the example of zero_user_segment() when clearing a partial page, add flush_dcache_page() and set_page_dirty() when clearing a hole - though I'm not certain that either is needed. But: split_huge_page() would be sure to fail if shmem_undo_range()'s pagevec holds further references to the huge page. The easiest way to fix that is for find_get_entries() to return early, as soon as it has put one compound head or tail into the pagevec. At first this felt like a hack; but on examination, this convention better suits all its callers - or will do, if the slight one-page-per-pagevec slowdown in shmem_unlock_mapping() and shmem_seek_hole_data() is transformed into a 512-page-per-pagevec speedup by checking for compound pages there. Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2002261959020.10801@eggly.anvils Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/shmem.c: clean code by removing unnecessary assignmentMateusz Nosek2020-04-071-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | Previously 0 was assigned to variable 'error' but the variable was never read before reassignemnt later. So the assignment can be removed. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200301152832.24595-1-mateusznosek0@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/shmem.c: distribute switch variables for initializationKees Cook2020-04-071-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Variables declared in a switch statement before any case statements cannot be automatically initialized with compiler instrumentation (as they are not part of any execution flow). With GCC's proposed automatic stack variable initialization feature, this triggers a warning (and they don't get initialized). Clang's automatic stack variable initialization (via CONFIG_INIT_STACK_ALL=y) doesn't throw a warning, but it also doesn't initialize such variables[1]. Note that these warnings (or silent skipping) happen before the dead-store elimination optimization phase, so even when the automatic initializations are later elided in favor of direct initializations, the warnings remain. To avoid these problems, move such variables into the "case" where they're used or lift them up into the main function body. mm/shmem.c: In function `shmem_getpage_gfp': mm/shmem.c:1816:10: warning: statement will never be executed [-Wswitch-unreachable] 1816 | loff_t i_size; | ^~~~~~ [1] https://bugs.llvm.org/show_bug.cgi?id=44916 Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Alexander Potapenko <glider@google.com> Link: http://lkml.kernel.org/r/20200220062312.69165-1-keescook@chromium.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/memory_hotplug.c: use __pfn_to_section() instead of open-codingchenqiwu2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | Use __pfn_to_section() API instead of open-coding for better code readability. Signed-off-by: chenqiwu <chenqiwu@xiaomi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Hildenbrand <david@redhat.com> Link: http://lkml.kernel.org/r/1584345134-16671-1-git-send-email-qiwuchen55@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/memory_hotplug: allow to specify a default online_typeDavid Hildenbrand2020-04-071-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For now, distributions implement advanced udev rules to essentially - Don't online any hotplugged memory (s390x) - Online all memory to ZONE_NORMAL (e.g., most virt environments like hyperv) - Online all memory to ZONE_MOVABLE in case the zone imbalance is taken care of (e.g., bare metal, special virt environments) In summary: All memory is usually onlined the same way, however, the kernel always has to ask user space to come up with the same answer. E.g., Hyper-V always waits for a memory block to get onlined before continuing, otherwise it might end up adding memory faster than onlining it, which can result in strange OOM situations. This waiting slows down adding of a bigger amount of memory. Let's allow to specify a default online_type, not just "online" and "offline". This allows distributions to configure the default online_type when booting up and be done with it. We can now specify "offline", "online", "online_movable" and "online_kernel" via - "memhp_default_state=" on the kernel cmdline - /sys/devices/system/memory/auto_online_blocks just like we are able to specify for a single memory block via /sys/devices/system/memory/memoryX/state Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Yumei Huang <yuhuang@redhat.com> Link: http://lkml.kernel.org/r/20200317104942.11178-9-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/memory_hotplug: convert memhp_auto_online to store an online_typeDavid Hildenbrand2020-04-071-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ... and rename it to memhp_default_online_type. This is a preparation for more detailed default online behavior. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Yumei Huang <yuhuang@redhat.com> Link: http://lkml.kernel.org/r/20200317104942.11178-8-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/memory_hotplug: unexport memhp_auto_onlineDavid Hildenbrand2020-04-071-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All in-tree users except the mm-core are gone. Let's drop the export. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Yumei Huang <yuhuang@redhat.com> Link: http://lkml.kernel.org/r/20200317104942.11178-7-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/sparse.c: move subsection_map related functions togetherBaoquan He2020-04-071-57/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No functional change. [bhe@redhat.com: move functions into CONFIG_MEMORY_HOTPLUG ifdeffery scope] Link: http://lkml.kernel.org/r/20200316045804.GC3486@MiWiFi-R3L-srv Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: David Hildenbrand <david@redhat.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: http://lkml.kernel.org/r/20200312124414.439-6-bhe@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/sparse.c: add note about only VMEMMAP supporting sub-section hotplugBaoquan He2020-04-071-17/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | And tell check_pfn_span() gating the porper alignment and size of hot added memory region. And also move the code comments from inside section_deactivate() to being above it. The code comments are reasonable for the whole function, and the moving makes code cleaner. Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Link: http://lkml.kernel.org/r/20200312124414.439-5-bhe@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/sparse.c: only use subsection map in VMEMMAP caseBaoquan He2020-04-071-0/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, to support subsection aligned memory region adding for pmem, subsection map is added to track which subsection is present. However, config ZONE_DEVICE depends on SPARSEMEM_VMEMMAP. It means subsection map only makes sense when SPARSEMEM_VMEMMAP enabled. For the classic sparse, it's meaningless. Even worse, it may confuse people when checking code related to the classic sparse. About the classic sparse which doesn't support subsection hotplug, Dan said it's more because the effort and maintenance burden outweighs the benefit. Besides, the current 64 bit ARCHes all enable SPARSEMEM_VMEMMAP_ENABLE by default. Combining the above reasons, no need to provide subsection map and the relevant handling for the classic sparse. Let's remove them. Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Link: http://lkml.kernel.org/r/20200312124414.439-4-bhe@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/sparse.c: introduce a new function clear_subsection_map()Baoquan He2020-04-071-8/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Factor out the code which clear subsection map of one memory region from section_deactivate() into clear_subsection_map(). And also add helper function is_subsection_map_empty() to check if the current subsection map is empty or not. Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Wei Yang <richard.weiyang@gmail.com> Link: http://lkml.kernel.org/r/20200312124414.439-3-bhe@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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