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* flush_tlb_range() needs ->page_table_lock when ->mmap_sem is not heldAl Viro2012-03-051-1/+1
| | | | | | | | | | | | | | | | | | All other callers already hold either ->mmap_sem (exclusive) or ->page_table_lock. And we need it because some page table flushing instanced do work explicitly with ge tables. See e.g. arch/powerpc/mm/tlb_hash32.c, flush_tlb_range() and flush_range() in there. The same goes for uml, with a lot more extensive playing with page tables. Almost all callers are actually fine - flush_tlb_range() may have no need to bother playing with page tables, but it can do so safely; again, this caller is the sole exception - everything else either has exclusive ->mmap_sem on the mm in question, or mm->page_table_lock is held. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/hugetlb.c: undo change to page mapcount in fault handlerHillf Danton2012-01-231-3/+6
| | | | | | | | | | | | Page mapcount should be updated only if we are sure that the page ends up in the page table otherwise we would leak if we couldn't COW due to reservations or if idx is out of bounds. Signed-off-by: Hillf Danton <dhillf@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/hugetlb.c: avoid bogus counter of surplus huge pageHillf Danton2012-01-111-1/+1
| | | | | | | | | | | | | | | If we have to hand back the newly allocated huge page to page allocator, for any reason, the changed counter should be recovered. This affects only s390 at present. Signed-off-by: Hillf Danton <dhillf@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: hugetlb: fix pgoff computation when unmapping page from vmaHillf Danton2012-01-111-2/+1
| | | | | | | | | | | | | | | | | | | | The computation for pgoff is incorrect, at least with (vma->vm_pgoff >> PAGE_SHIFT) involved. It is fixed with the available method if HPAGE_SIZE is concerned in page cache lookup. [akpm@linux-foundation.org: use vma_hugecache_offset() directly, per Michal] Signed-off-by: Hillf Danton <dhillf@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michal Hocko <mhocko@suse.cz> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/hugetlb.c: fix virtual address handling in hugetlb faultKAMEZAWA Hiroyuki2012-01-111-0/+2
| | | | | | | | | | | | | | | | | | | handle_mm_fault() passes 'faulted' address to hugetlb_fault(). This address is not aligned to a hugepage boundary. Most of the functions for hugetlb pages are aware of that and calculate an alignment themselves. However some functions such as copy_user_huge_page() and clear_huge_page() don't handle alignment by themselves. This patch make hugeltb_fault() fix the alignment and pass an aligned addresss (to address of a faulted hugepage) to functions. [akpm@linux-foundation.org: use &=] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: clarify hugetlb_instantiation_mutex usageMichal Hocko2012-01-111-0/+3
| | | | | | | | | | | | | Let's make it clear that we cannot race with other fault handlers due to hugetlb (global) mutex. Also make it clear that we want to keep pte_same checks anayway to have a transition from the global mutex easier. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Hillf Danton <dhillf@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: detect race upon page allocation failure during COWHillf Danton2012-01-111-1/+8
| | | | | | | | | | | | | | | | | | | | | | Currently we are not rechecking pte_same in hugetlb_cow after we take ptl lock again in the page allocation failure code path and simply retry again. This is not an issue at the moment because hugetlb fault path is protected by hugetlb_instantiation_mutex so we cannot race. The original page is locked and so we cannot race even with the page migration. Let's add the pte_same check anyway as we want to be consistent with the other check later in this function and be safe if we ever remove the mutex. [mhocko@suse.cz: reworded the changelog] Signed-off-by: Hillf Danton <dhillf@gmail.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'driver-core-next' into Linux 3.2Greg Kroah-Hartman2012-01-061-17/+17
|\ | | | | | | | | | | | | | | | | | | | | | | This resolves the conflict in the arch/arm/mach-s3c64xx/s3c6400.c file, and it fixes the build error in the arch/x86/kernel/microcode_core.c file, that the merge did not catch. The microcode_core.c patch was provided by Stephen Rothwell <sfr@canb.auug.org.au> who was invaluable in the merge issues involved with the large sysdev removal process in the driver-core tree. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * convert 'memory' sysdev_class to a regular subsystemKay Sievers2011-12-211-17/+17
| | | | | | | | | | | | | | | | | | | | | | | | This moves the 'memory sysdev_class' over to a regular 'memory' subsystem and converts the devices to regular devices. The sysdev drivers are implemented as subsystem interfaces now. After all sysdev classes are ported to regular driver core entities, the sysdev implementation will be entirely removed from the kernel. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | mm: hugetlb: fix non-atomic enqueue of huge pageHillf Danton2011-12-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | If a huge page is enqueued under the protection of hugetlb_lock, then the operation is atomic and safe. Signed-off-by: Hillf Danton <dhillf@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@vger.kernel.org> [2.6.37+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | thp: set compound tail page _count to zeroYouquan Song2011-12-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 70b50f94f1644 ("mm: thp: tail page refcounting fix") keeps all page_tail->_count zero at all times. But the current kernel does not set page_tail->_count to zero if a 1GB page is utilized. So when an IOMMU 1GB page is used by KVM, it wil result in a kernel oops because a tail page's _count does not equal zero. kernel BUG at include/linux/mm.h:386! invalid opcode: 0000 [#1] SMP Call Trace: gup_pud_range+0xb8/0x19d get_user_pages_fast+0xcb/0x192 ? trace_hardirqs_off+0xd/0xf hva_to_pfn+0x119/0x2f2 gfn_to_pfn_memslot+0x2c/0x2e kvm_iommu_map_pages+0xfd/0x1c1 kvm_iommu_map_memslots+0x7c/0xbd kvm_iommu_map_guest+0xaa/0xbf kvm_vm_ioctl_assigned_device+0x2ef/0xa47 kvm_vm_ioctl+0x36c/0x3a2 do_vfs_ioctl+0x49e/0x4e4 sys_ioctl+0x5a/0x7c system_call_fastpath+0x16/0x1b RIP gup_huge_pud+0xf2/0x159 Signed-off-by: Youquan Song <youquan.song@intel.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | hugetlb: release pages in the error path of hugetlb_cow()Hillf Danton2011-11-161-0/+2
|/ | | | | | | | | | | | If we fail to prepare an anon_vma, the {new, old}_page should be released, or they will leak. Signed-off-by: Hillf Danton <dhillf@gmail.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: hugetlb: fix coding style issuesChris Forbes2011-07-261-16/+15
| | | | | | | | | Fix coding style issues flagged by checkpatch.pl Signed-off-by: Chris Forbes <chrisf@ijw.co.nz> Acked-by: Eric B Munson <emunson@mgebm.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: add phys addr to struct huge_bootmem_pageBecky Bruce2011-07-261-1/+9
| | | | | | | | | | | This is needed on HIGHMEM systems - we don't always have a virtual address so store the physical address and map it in as needed. [akpm@linux-foundation.org: cleanup] Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix negative commitlimit when gigantic hugepages are allocatedRafael Aquini2011-06-161-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When 1GB hugepages are allocated on a system, free(1) reports less available memory than what really is installed in the box. Also, if the total size of hugepages allocated on a system is over half of the total memory size, CommitLimit becomes a negative number. The problem is that gigantic hugepages (order > MAX_ORDER) can only be allocated at boot with bootmem, thus its frames are not accounted to 'totalram_pages'. However, they are accounted to hugetlb_total_pages() What happens to turn CommitLimit into a negative number is this calculation, in fs/proc/meminfo.c: allowed = ((totalram_pages - hugetlb_total_pages()) * sysctl_overcommit_ratio / 100) + total_swap_pages; A similar calculation occurs in __vm_enough_memory() in mm/mmap.c. Also, every vm statistic which depends on 'totalram_pages' will render confusing values, as if system were 'missing' some part of its memory. Impact of this bug: When gigantic hugepages are allocated and sysctl_overcommit_memory == OVERCOMMIT_NEVER. In a such situation, __vm_enough_memory() goes through the mentioned 'allowed' calculation and might end up mistakenly returning -ENOMEM, thus forcing the system to start reclaiming pages earlier than it would be ususal, and this could cause detrimental impact to overall system's performance, depending on the workload. Besides the aforementioned scenario, I can only think of this causing annoyances with memory reports from /proc/meminfo and free(1). [akpm@linux-foundation.org: standardize comment layout] Reported-by: Russ Anderson <rja@sgi.com> Signed-off-by: Rafael Aquini <aquini@linux.com> Acked-by: Russ Anderson <rja@sgi.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix ENOSPC returned by handle_mm_fault()Hugh Dickins2011-06-061-2/+2
| | | | | | | | | | | Al Viro observes that in the hugetlb case, handle_mm_fault() may return a value of the kind ENOSPC when its caller is expecting a value of the kind VM_FAULT_SIGBUS: fix alloc_huge_page()'s failure returns. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: don't access vm_flags as 'int'KOSAKI Motohiro2011-05-261-2/+2
| | | | | | | | | | | The type of vma->vm_flags is 'unsigned long'. Neither 'int' nor 'unsigned int'. This patch fixes such misuse. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> [ Changed to use a typedef - we'll extend it to cover more cases later, since there has been discussion about making it a 64-bit type.. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: Convert i_mmap_lock to a mutexPeter Zijlstra2011-05-251-7/+7
| | | | | | | | | | | | | | | | | | | | | | Straightforward conversion of i_mmap_lock to a mutex. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Hugh Dickins <hughd@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Tony Luck <tony.luck@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'master' into for-nextJiri Kosina2011-04-261-9/+7
|\ | | | | | | | | Fast-forwarded to current state of Linus' tree as there are patches to be applied for files that didn't exist on the old branch.
| * Fix common misspellingsLucas De Marchi2011-03-311-5/+5
| | | | | | | | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
| * hugetlbfs: correct handling of negative input to /proc/sys/vm/nr_hugepagesPetr Holasek2011-03-231-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the user inserts a negative value into /proc/sys/vm/nr_hugepages it will cause the kernel to allocate as many hugepages as possible and to then update /proc/meminfo to reflect this. This changes the behavior so that the negative input will result in nr_hugepages value being unchanged. Signed-off-by: Petr Holasek <pholasek@redhat.com> Signed-off-by: Anton Arapov <anton@redhat.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Eric B Munson <emunson@mgebm.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | treewide: remove extra semicolonsJustin P. Mattock2011-04-101-1/+1
|/ | | | | Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* hugetlb: fix handling of parse errors in sysfsEric B Munson2011-01-141-4/+2
| | | | | | | | | | | | | | | | | | When parsing changes to the huge page pool sizes made from userspace via the sysfs interface, bogus input values are being covered up by nr_hugepages_store_common and nr_overcommit_hugepages_store returning 0 when strict_strtoul returns an error. This can cause an infinite loop in the nr_hugepages_store code. This patch changes the return value for these functions to -EINVAL when strict_strtoul returns an error. Signed-off-by: Eric B Munson <emunson@mgebm.net> Reported-by: CAI Qian <caiqian@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Eric B Munson <emunson@mgebm.net> Cc: Michal Hocko <mhocko@suse.cz> Cc: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: do not allow pagesize >= MAX_ORDER pool adjustmentEric B Munson2011-01-141-2/+21
| | | | | | | | | | | | | | | | | | | Huge pages with order >= MAX_ORDER must be allocated at boot via the kernel command line, they cannot be allocated or freed once the kernel is up and running. Currently we allow values to be written to the sysfs and sysctl files controling pool size for these huge page sizes. This patch makes the store functions for nr_hugepages and nr_overcommit_hugepages return -EINVAL when the pool for a page size >= MAX_ORDER is changed. [akpm@linux-foundation.org: avoid multiple return paths in nr_hugepages_store_common()] [caiqian@redhat.com: add checking in hugetlb_overcommit_handler()] Signed-off-by: Eric B Munson <emunson@mgebm.net> Reported-by: CAI Qian <caiqian@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: check the return value of string conversion in sysctl handlerMichal Hocko2011-01-141-6/+12
| | | | | | | | | | | | | | | | | | | | | proc_doulongvec_minmax may fail if the given buffer doesn't represent a valid number. If we provide something invalid we will initialize the resulting value (nr_overcommit_huge_pages in this case) to a random value from the stack. The issue was introduced by a3d0c6aa when the default handler has been replaced by the helper function where we do not check the return value. Reproducer: echo "" > /proc/sys/vm/nr_overcommit_hugepages [akpm@linux-foundation.org: correctly propagate proc_doulongvec_minmax return code] Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: CAI Qian <caiqian@redhat.com> Cc: Nishanth Aravamudan <nacc@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/hugetlb.c: fix error-path memory leak in nr_hugepages_store_common()Jesper Juhl2011-01-141-1/+3
| | | | | | | | | | | | | | | | | The NODEMASK_ALLOC macro may dynamically allocate memory for its second argument ('nodes_allowed' in this context). In nr_hugepages_store_common() we may abort early if strict_strtoul() fails, but in that case we do not free the memory already allocated to 'nodes_allowed', causing a memory leak. This patch closes the leak by freeing the memory in the error path. [akpm@linux-foundation.org: use NODEMASK_FREE, per Minchan Kim] Signed-off-by: Jesper Juhl <jj@chaosbits.net> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* thp: clear_copy_huge_pageAndrea Arcangeli2011-01-141-67/+3
| | | | | | | | | | | Move the copy/clear_huge_page functions to common code to share between hugetlb.c and huge_memory.c. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/hugetlb.c: avoid double unlock_page() in hugetlb_fault()Dean Nelson2010-12-021-1/+2
| | | | | | | | | | | | | | | Have hugetlb_fault() call unlock_page(page) only if it had previously called lock_page(page). Setting CONFIG_DEBUG_VM=y and then running the libhugetlbfs test suite, resulted in the tripping of VM_BUG_ON(!PageLocked(page)) in unlock_page() having been called by hugetlb_fault() when page == pagecache_page. This patch remedied the problem. Signed-off-by: Dean Nelson <dnelson@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/hugetlb.c: add missing spin_lock() to hugetlb_cow()Dean Nelson2010-10-271-1/+4
| | | | | | | | | | | Add missing spin_lock() of the page_table_lock before an error return in hugetlb_cow(). Callers of hugtelb_cow() expect it to be held upon return. Signed-off-by: Dean Nelson <dnelson@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Encode huge page size for VM_FAULT_HWPOISON errorsAndi Kleen2010-10-081-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | This fixes a problem introduced with the hugetlb hwpoison handling The user space SIGBUS signalling wants to know the size of the hugepage that caused a HWPOISON fault. Unfortunately the architecture page fault handlers do not have easy access to the struct page. Pass the information out in the fault error code instead. I added a separate VM_FAULT_HWPOISON_LARGE bit for this case and encode the hpage index in some free upper bits of the fault code. The small page hwpoison keeps stays with the VM_FAULT_HWPOISON name to minimize changes. Also add code to hugetlb.h to convert that index into a page shift. Will be used in a further patch. Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: fengguang.wu@intel.com Signed-off-by: Andi Kleen <ak@linux.intel.com>
* hugepage: move is_hugepage_on_freelist inside ifdef to avoid warningAndi Kleen2010-10-081-1/+2
| | | | | | | | | | Fixes warning reported by Stephen Rothwell mm/hugetlb.c:2950: warning: 'is_hugepage_on_freelist' defined but not used for the !CONFIG_MEMORY_FAILURE case. Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOSION, hugetlb: recover from free hugepage error when !MF_COUNT_INCREASEDNaoya Horiguchi2010-10-081-0/+1
| | | | | | | | | | | | | | | | | | | | | Currently error recovery for free hugepage works only for MF_COUNT_INCREASED. This patch enables !MF_COUNT_INCREASED case. Free hugepages can be handled directly by alloc_huge_page() and dequeue_hwpoisoned_huge_page(), and both of them are protected by hugetlb_lock, so there is no race between them. Note that this patch defines the refcount of HWPoisoned hugepage dequeued from freelist is 1, deviated from present 0, thereby we can avoid race between unpoison and memory failure on free hugepage. This is reasonable because unlikely to free buddy pages, free hugepage is governed by hugetlbfs even after error handling finishes. And it also makes unpoison code added in the later patch cleaner. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* hugetlb: move refcounting in hugepage allocation inside hugetlb_lockNaoya Horiguchi2010-10-081-22/+13
| | | | | | | | | | | | | Currently alloc_huge_page() raises page refcount outside hugetlb_lock. but it causes race when dequeue_hwpoison_huge_page() runs concurrently with alloc_huge_page(). To avoid it, this patch moves set_page_refcounted() in hugetlb_lock. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON, hugetlb: add free check to dequeue_hwpoison_huge_page()Naoya Horiguchi2010-10-081-4/+25
| | | | | | | | | | | This check is necessary to avoid race between dequeue and allocation, which can cause a free hugepage to be dequeued twice and get kernel unstable. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* hugetlb: hugepage migration coreNaoya Horiguchi2010-10-081-1/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch extends page migration code to support hugepage migration. One of the potential users of this feature is soft offlining which is triggered by memory corrected errors (added by the next patch.) Todo: - there are other users of page migration such as memory policy, memory hotplug and memocy compaction. They are not ready for hugepage support for now. ChangeLog since v4: - define migrate_huge_pages() - remove changes on isolation/putback_lru_page() ChangeLog since v2: - refactor isolate/putback_lru_page() to handle hugepage - add comment about race on unmap_and_move_huge_page() ChangeLog since v1: - divide migration code path for hugepage - define routine checking migration swap entry for hugetlb - replace "goto" with "if/else" in remove_migration_pte() Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* hugetlb: redefine hugepage copy functionsNaoya Horiguchi2010-10-081-5/+40
| | | | | | | | | | | | | | | | | | | | | | This patch modifies hugepage copy functions to have only destination and source hugepages as arguments for later use. The old ones are renamed from copy_{gigantic,huge}_page() to copy_user_{gigantic,huge}_page(). This naming convention is consistent with that between copy_highpage() and copy_user_highpage(). ChangeLog since v4: - add blank line between local declaration and code - remove unnecessary might_sleep() ChangeLog since v2: - change copy_huge_page() from macro to inline dummy function to avoid compile warning when !CONFIG_HUGETLB_PAGE. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* hugetlb: add allocate function for hugepage migrationNaoya Horiguchi2010-10-081-25/+54
| | | | | | | | | | | | | | | | | | | | | | We can't use existing hugepage allocation functions to allocate hugepage for page migration, because page migration can happen asynchronously with the running processes and page migration users should call the allocation function with physical addresses (not virtual addresses) as arguments. ChangeLog since v3: - unify alloc_buddy_huge_page() and alloc_buddy_huge_page_node() ChangeLog since v2: - remove unnecessary get/put_mems_allowed() (thanks to David Rientjes) ChangeLog since v1: - add comment on top of alloc_huge_page_no_vma() Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* hugetlb: fix metadata corruption in hugetlb_fault()Naoya Horiguchi2010-10-081-12/+9
| | | | | | | | | | | | | | | | | | | | | | | Since the PageHWPoison() check is for avoiding hwpoisoned page remained in pagecache mapping to the process, it should be done in "found in pagecache" branch, not in the common path. Otherwise, metadata corruption occurs if memory failure happens between alloc_huge_page() and lock_page() because page fault fails with metadata changes remained (such as refcount, mapcount, etc.) This patch moves the check to "found in pagecache" branch and fix the problem. ChangeLog since v2: - remove retry check in "new allocation" path. - make description more detailed - change patch name from "HWPOISON, hugetlb: move PG_HWPoison bit check" Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* hugetlb, rmap: fix confusing page locking in hugetlb_cow()Naoya Horiguchi2010-09-241-10/+12
| | | | | | | | | | | | | The "if (!trylock_page)" block in the avoidcopy path of hugetlb_cow() looks confusing and is buggy. Originally this trylock_page() was intended to make sure that old_page is locked even when old_page != pagecache_page, because then only pagecache_page is locked. This patch fixes it by moving page locking into hugetlb_fault(). Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb, rmap: use hugepage_add_new_anon_rmap() in hugetlb_cow()Naoya Horiguchi2010-09-241-1/+1
| | | | | | | | | | | Obviously, setting anon_vma for COWed hugepage should be done by hugepage_add_new_anon_rmap() to scan vmas faster. This patch fixes it. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'hwpoison' of ↵Linus Torvalds2010-08-121-2/+102
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 * 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: hugetlb: add missing unlock in avoidcopy path in hugetlb_cow() hwpoison: rename CONFIG HWPOISON, hugetlb: support hwpoison injection for hugepage HWPOISON, hugetlb: detect hwpoison in hugetlb code HWPOISON, hugetlb: isolate corrupted hugepage HWPOISON, hugetlb: maintain mce_bad_pages in handling hugepage error HWPOISON, hugetlb: set/clear PG_hwpoison bits on hugepage HWPOISON, hugetlb: enable error handling path for hugepage hugetlb, rmap: add reverse mapping for hugepage hugetlb: move definition of is_vm_hugetlb_page() to hugepage_inline.h Fix up trivial conflicts in mm/memory-failure.c
| * hugetlb: add missing unlock in avoidcopy path in hugetlb_cow()Naoya Horiguchi2010-08-111-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes possible deadlock in hugepage lock_page() by adding missing unlock_page(). libhugetlbfs test will hit this bug when the next patch in this patchset ("hugetlb, HWPOISON: move PG_HWPoison bit check") is applied. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
| * HWPOISON, hugetlb: support hwpoison injection for hugepageNaoya Horiguchi2010-08-111-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | This patch enables hwpoison injection through debug/hwpoison interfaces, with which we can test memory error handling for free or reserved hugepages (which cannot be tested by madvise() injector). [AK: Export PageHuge too for the injection module] Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrew Morton <akpm@linux-foundation.org> Acked-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
| * HWPOISON, hugetlb: detect hwpoison in hugetlb codeNaoya Horiguchi2010-08-111-0/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch enables to block access to hwpoisoned hugepage and also enables to block unmapping for it. Dependency: "HWPOISON, hugetlb: enable error handling path for hugepage" Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrew Morton <akpm@linux-foundation.org> Acked-by: Fengguang Wu <fengguang.wu@intel.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andi Kleen <ak@linux.intel.com>
| * HWPOISON, hugetlb: isolate corrupted hugepageNaoya Horiguchi2010-08-111-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If error hugepage is not in-use, we can fully recovery from error by dequeuing it from freelist, so return RECOVERY. Otherwise whether or not we can recovery depends on user processes, so return DELAYED. Dependency: "HWPOISON, hugetlb: enable error handling path for hugepage" Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrew Morton <akpm@linux-foundation.org> Acked-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
| * hugetlb, rmap: add reverse mapping for hugepageNaoya Horiguchi2010-08-111-2/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds reverse mapping feature for hugepage by introducing mapcount for shared/private-mapped hugepage and anon_vma for private-mapped hugepage. While hugepage is not currently swappable, reverse mapping can be useful for memory error handler. Without this patch, memory error handler cannot identify processes using the bad hugepage nor unmap it from them. That is: - for shared hugepage: we can collect processes using a hugepage through pagecache, but can not unmap the hugepage because of the lack of mapcount. - for privately mapped hugepage: we can neither collect processes nor unmap the hugepage. This patch solves these problems. This patch include the bug fix given by commit 23be7468e8, so reverts it. Dependency: "hugetlb: move definition of is_vm_hugetlb_page() to hugepage_inline.h" ChangeLog since May 24. - create hugetlb_inline.h and move is_vm_hugetlb_index() in it. - move functions setting up anon_vma for hugepage into mm/rmap.c. ChangeLog since May 13. - rebased to 2.6.34 - fix logic error (in case that private mapping and shared mapping coexist) - move is_vm_hugetlb_page() into include/linux/mm.h to use this function from linear_page_index() - define and use linear_hugepage_index() instead of compound_order() - use page_move_anon_rmap() in hugetlb_cow() - copy exclusive switch of __set_page_anon_rmap() into hugepage counterpart. - revert commit 24be7468 completely Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Acked-by: Fengguang Wu <fengguang.wu@intel.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* | hugetlb: call mmu notifiers on hugepage cowDoug Doan2010-08-101-0/+6
|/ | | | | | | | | | | | | | | | When a copy-on-write occurs, we take one of two paths in handle_mm_fault: through handle_pte_fault for normal pages, or through hugetlb_fault for huge pages. In the normal page case, we eventually get to do_wp_page and call mmu notifiers via ptep_clear_flush_notify. There is no callout to the mmmu notifiers in the huge page case. This patch fixes that. Signed-off-by: Doug Doan <dougd@cray.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cpuset,mm: fix no node to alloc memory when changing cpuset's memsMiao Xie2010-05-251-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before applying this patch, cpuset updates task->mems_allowed and mempolicy by setting all new bits in the nodemask first, and clearing all old unallowed bits later. But in the way, the allocator may find that there is no node to alloc memory. The reason is that cpuset rebinds the task's mempolicy, it cleans the nodes which the allocater can alloc pages on, for example: (mpol: mempolicy) task1 task1's mpol task2 alloc page 1 alloc on node0? NO 1 1 change mems from 1 to 0 1 rebind task1's mpol 0-1 set new bits 0 clear disallowed bits alloc on node1? NO 0 ... can't alloc page goto oom This patch fixes this problem by expanding the nodes range first(set newly allowed bits) and shrink it lazily(clear newly disallowed bits). So we use a variable to tell the write-side task that read-side task is reading nodemask, and the write-side task clears newly disallowed nodes after read-side task ends the current memory allocation. [akpm@linux-foundation.org: fix spello] Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Paul Menage <menage@google.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlbfs: kill applications that use MAP_NORESERVE with SIGBUS instead of ↵Mel Gorman2010-05-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | OOM-killer Ordinarily, application using hugetlbfs will create mappings with reserves. For shared mappings, these pages are reserved before mmap() returns success and for private mappings, the caller process is guaranteed and a child process that cannot get the pages gets killed with sigbus. An application that uses MAP_NORESERVE gets no reservations and mmap() will always succeed at the risk the page will not be available at fault time. This might be used for example on very large sparse mappings where the developer is confident the necessary huge pages exist to satisfy all faults even though the whole mapping cannot be backed by huge pages. Unfortunately, if an allocation does fail, VM_FAULT_OOM is returned to the fault handler which proceeds to trigger the OOM-killer. This is unhelpful. Even without hugetlbfs mounted, a user using mmap() can trivially trigger the OOM-killer because VM_FAULT_OOM is returned (will provide example program if desired - it's a whopping 24 lines long). It could be considered a DOS available to an unprivileged user. This patch alters hugetlbfs to kill a process that uses MAP_NORESERVE where huge pages were not available with SIGBUS instead of triggering the OOM killer. This change affects hugetlb_cow() as well. I feel there is a failure case in there, but I didn't create one. It would need a fairly specific target in terms of the faulting application and the hugepage pool size. The hugetlb_no_page() path is much easier to hit but both might as well be closed. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: David Rientjes <rientjes@google.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: fix infinite loop in get_futex_key() when backed by huge pagesMel Gorman2010-04-241-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | If a futex key happens to be located within a huge page mapped MAP_PRIVATE, get_futex_key() can go into an infinite loop waiting for a page->mapping that will never exist. See https://bugzilla.redhat.com/show_bug.cgi?id=552257 for more details about the problem. This patch makes page->mapping a poisoned value that includes PAGE_MAPPING_ANON mapped MAP_PRIVATE. This is enough for futex to continue but because of PAGE_MAPPING_ANON, the poisoned value is not dereferenced or used by futex. No other part of the VM should be dereferencing the page->mapping of a hugetlbfs page as its page cache is not on the LRU. This patch fixes the problem with the test case described in the bugzilla. [akpm@linux-foundation.org: mel cant spel] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Darren Hart <darren@dvhart.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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