- 13 1月, 2012 6 次提交
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由 Hugh Dickins 提交于
This patch started off as a cleanup: __split_huge_page_refcounts() has to cope with two scenarios, when the hugepage being split is already on LRU, and when it is not; but why does it have to split that accounting across three different sites? Consolidate it in lru_add_page_tail(), handling evictable and unevictable alike, and use standard add_page_to_lru_list() when accounting is needed (when the head is not yet on LRU). But a recent regression in -next, I guess the removal of PageCgroupAcctLRU test from mem_cgroup_split_huge_fixup(), makes this now a necessary fix: under load, the MEM_CGROUP_ZSTAT count was wrapping to a huge number, messing up reclaim calculations and causing a freeze at rmdir of cgroup. Add a VM_BUG_ON to mem_cgroup_lru_del_list() when we're about to wrap that count - this has not been the only such incident. Document that lru_add_page_tail() is for Transparent HugePages by #ifdef around it. Signed-off-by: NHugh Dickins <hughd@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Shaohua Li 提交于
Put the tail subpages of an isolated hugepage under splitting in the lru reclaim head as they supposedly should be isolated too next. Queues the subpages in physical order in the lru for non isolated hugepages under splitting. That might provide some theoretical cache benefit to the buddy allocator later. Signed-off-by: NShaohua Li <shaohua.li@intel.com> Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Shaohua Li 提交于
We have tlb_remove_tlb_entry to indicate a pte tlb flush entry should be flushed, but not a corresponding API for pmd entry. This isn't a problem so far because THP is only for x86 currently and tlb_flush() under x86 will flush entire TLB. But this is confusion and could be missed if thp is ported to other arch. Also convert tlb->need_flush = 1 to a VM_BUG_ON(!tlb->need_flush) in __tlb_remove_page() as suggested by Andrea Arcangeli. The __tlb_remove_page() function is supposed to be called after tlb_remove_xxx_tlb_entry() and we can catch any misuse. Signed-off-by: NShaohua Li <shaohua.li@intel.com> Reviewed-by: NAndrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Shaohua Li 提交于
change_protection() will do TLB flush later, don't need duplicate tlb flush. Signed-off-by: NShaohua Li <shaohua.li@intel.com> Reviewed-by: NAndrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Shaohua Li 提交于
Improve the error code path. Delete unnecessary sysfs file for example. Also remove the #ifdef xxx to make code better. Signed-off-by: NShaohua Li <shaohua.li@intel.com> Reviewed-by: NAndrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KAMEZAWA Hiroyuki 提交于
In split_huge_page(), mem_cgroup_split_huge_fixup() is called to handle page_cgroup modifcations. It takes move_lock_page_cgroup() and modifies page_cgroup and LRU accounting jobs and called HPAGE_PMD_SIZE - 1 times. But thinking again, - compound_lock() is held at move_accout...then, it's not necessary to take move_lock_page_cgroup(). - LRU is locked and all tail pages will go into the same LRU as head is now on. - page_cgroup is contiguous in huge page range. This patch fixes mem_cgroup_split_huge_fixup() as to be called once per hugepage and reduce costs for spliting. [akpm@linux-foundation.org: fix typo, per Michal] Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: NMichal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 09 12月, 2011 1 次提交
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由 Andrea Arcangeli 提交于
khugepaged can sometimes cause suspend to fail, requiring that the user retry the suspend operation. Use wait_event_freezable_timeout() instead of schedule_timeout_interruptible() to avoid missing freezer wakeups. A try_to_freeze() would have been needed in the khugepaged_alloc_hugepage tight loop too in case of the allocation failing repeatedly, and wait_event_freezable_timeout will provide it too. khugepaged would still freeze just fine by trying again the next minute but it's better if it freezes immediately. Reported-by: NJiri Slaby <jslaby@suse.cz> Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Tested-by: NJiri Slaby <jslaby@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com> Cc: "Rafael J. Wysocki" <rjw@suse.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 03 11月, 2011 1 次提交
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由 Andrea Arcangeli 提交于
Michel while working on the working set estimation code, noticed that calling get_page_unless_zero() on a random pfn_to_page(random_pfn) wasn't safe, if the pfn ended up being a tail page of a transparent hugepage under splitting by __split_huge_page_refcount(). He then found the problem could also theoretically materialize with page_cache_get_speculative() during the speculative radix tree lookups that uses get_page_unless_zero() in SMP if the radix tree page is freed and reallocated and get_user_pages is called on it before page_cache_get_speculative has a chance to call get_page_unless_zero(). So the best way to fix the problem is to keep page_tail->_count zero at all times. This will guarantee that get_page_unless_zero() can never succeed on any tail page. page_tail->_mapcount is guaranteed zero and is unused for all tail pages of a compound page, so we can simply account the tail page references there and transfer them to tail_page->_count in __split_huge_page_refcount() (in addition to the head_page->_mapcount). While debugging this s/_count/_mapcount/ change I also noticed get_page is called by direct-io.c on pages returned by get_user_pages. That wasn't entirely safe because the two atomic_inc in get_page weren't atomic. As opposed to other get_user_page users like secondary-MMU page fault to establish the shadow pagetables would never call any superflous get_page after get_user_page returns. It's safer to make get_page universally safe for tail pages and to use get_page_foll() within follow_page (inside get_user_pages()). get_page_foll() is safe to do the refcounting for tail pages without taking any locks because it is run within PT lock protected critical sections (PT lock for pte and page_table_lock for pmd_trans_huge). The standard get_page() as invoked by direct-io instead will now take the compound_lock but still only for tail pages. The direct-io paths are usually I/O bound and the compound_lock is per THP so very finegrined, so there's no risk of scalability issues with it. A simple direct-io benchmarks with all lockdep prove locking and spinlock debugging infrastructure enabled shows identical performance and no overhead. So it's worth it. Ideally direct-io should stop calling get_page() on pages returned by get_user_pages(). The spinlock in get_page() is already optimized away for no-THP builds but doing get_page() on tail pages returned by GUP is generally a rare operation and usually only run in I/O paths. This new refcounting on page_tail->_mapcount in addition to avoiding new RCU critical sections will also allow the working set estimation code to work without any further complexity associated to the tail page refcounting with THP. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Reported-by: NMichel Lespinasse <walken@google.com> Reviewed-by: NMichel Lespinasse <walken@google.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: <stable@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 01 11月, 2011 4 次提交
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由 Hillf Danton 提交于
There are three cases of update_mmu_cache() in the file, and the case in function collapse_huge_page() has a typo, namely the last parameter used, which is corrected based on the other two cases. Due to the define of update_mmu_cache by X86, the only arch that implements THP currently, the change here has no really crystal point, but one or two minutes of efforts could be saved for those archs that are likely to support THP in future. Signed-off-by: NHillf Danton <dhillf@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Reviewed-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hillf Danton 提交于
The THP copy-on-write handler falls back to regular-sized pages for a huge page replacement upon allocation failure or if THP has been individually disabled in the target VMA. The loop responsible for copying page-sized chunks accidentally uses multiples of PAGE_SHIFT instead of PAGE_SIZE as the virtual address arg for copy_user_highpage(). Signed-off-by: NHillf Danton <dhillf@gmail.com> Acked-by: NJohannes Weiner <jweiner@redhat.com> Reviewed-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 H Hartley Sweeten 提交于
Quiet the sparse noise: warning: symbol 'khugepaged_scan' was not declared. Should it be static? warning: context imbalance in 'khugepaged_scan_mm_slot' - unexpected unlock Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
This adds THP support to mremap (decreases the number of split_huge_page() calls). Here are also some benchmarks with a proggy like this: === #define _GNU_SOURCE #include <sys/mman.h> #include <stdlib.h> #include <stdio.h> #include <string.h> #include <sys/time.h> #define SIZE (5UL*1024*1024*1024) int main() { static struct timeval oldstamp, newstamp; long diffsec; char *p, *p2, *p3, *p4; if (posix_memalign((void **)&p, 2*1024*1024, SIZE)) perror("memalign"), exit(1); if (posix_memalign((void **)&p2, 2*1024*1024, SIZE)) perror("memalign"), exit(1); if (posix_memalign((void **)&p3, 2*1024*1024, 4096)) perror("memalign"), exit(1); memset(p, 0xff, SIZE); memset(p2, 0xff, SIZE); memset(p3, 0x77, 4096); gettimeofday(&oldstamp, NULL); p4 = mremap(p, SIZE, SIZE, MREMAP_FIXED|MREMAP_MAYMOVE, p3); gettimeofday(&newstamp, NULL); diffsec = newstamp.tv_sec - oldstamp.tv_sec; diffsec = newstamp.tv_usec - oldstamp.tv_usec + 1000000 * diffsec; printf("usec %ld\n", diffsec); if (p == MAP_FAILED || p4 != p3) //if (p == MAP_FAILED) perror("mremap"), exit(1); if (memcmp(p4, p2, SIZE)) printf("mremap bug\n"), exit(1); printf("ok\n"); return 0; } === THP on Performance counter stats for './largepage13' (3 runs): 69195836 dTLB-loads ( +- 3.546% ) (scaled from 50.30%) 60708 dTLB-load-misses ( +- 11.776% ) (scaled from 52.62%) 676266476 dTLB-stores ( +- 5.654% ) (scaled from 69.54%) 29856 dTLB-store-misses ( +- 4.081% ) (scaled from 89.22%) 1055848782 iTLB-loads ( +- 4.526% ) (scaled from 80.18%) 8689 iTLB-load-misses ( +- 2.987% ) (scaled from 58.20%) 7.314454164 seconds time elapsed ( +- 0.023% ) THP off Performance counter stats for './largepage13' (3 runs): 1967379311 dTLB-loads ( +- 0.506% ) (scaled from 60.59%) 9238687 dTLB-load-misses ( +- 22.547% ) (scaled from 61.87%) 2014239444 dTLB-stores ( +- 0.692% ) (scaled from 60.40%) 3312335 dTLB-store-misses ( +- 7.304% ) (scaled from 67.60%) 6764372065 iTLB-loads ( +- 0.925% ) (scaled from 79.00%) 8202 iTLB-load-misses ( +- 0.475% ) (scaled from 70.55%) 9.693655243 seconds time elapsed ( +- 0.069% ) grep thp /proc/vmstat thp_fault_alloc 35849 thp_fault_fallback 0 thp_collapse_alloc 3 thp_collapse_alloc_failed 0 thp_split 0 thp_split 0 confirms no thp split despite plenty of hugepages allocated. The measurement of only the mremap time (so excluding the 3 long memset and final long 10GB memory accessing memcmp): THP on usec 14824 usec 14862 usec 14859 THP off usec 256416 usec 255981 usec 255847 With an older kernel without the mremap optimizations (the below patch optimizes the non THP version too). THP on usec 392107 usec 390237 usec 404124 THP off usec 444294 usec 445237 usec 445820 I guess with a threaded program that sends more IPI on large SMP it'd create an even larger difference. All debug options are off except DEBUG_VM to avoid skewing the results. The only problem for native 2M mremap like it happens above both the source and destination address must be 2M aligned or the hugepmd can't be moved without a split but that is an hardware limitation. [akpm@linux-foundation.org: coding-style nitpicking] Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Acked-by: NJohannes Weiner <jweiner@redhat.com> Acked-by: NMel Gorman <mgorman@suse.de> Acked-by: NRik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 26 7月, 2011 1 次提交
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由 Chris Wright 提交于
The lock is released first thing in all three branches. Simplify this by unconditionally releasing lock and remove else clause which was only there to be sure lock was released. Signed-off-by: NChris Wright <chrisw@sous-sol.org> Reviewed-by: NMichal Hocko <mhocko@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Acked-by: NJohannes Weiner <jweiner@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 16 6月, 2011 1 次提交
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由 Andrea Arcangeli 提交于
Johannes noticed the vmstat update is already taken care of by khugepaged_alloc_hugepage() internally. The only places that are required to update the vmstat are the callers of alloc_hugepage (callers of khugepaged_alloc_hugepage aren't). Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Reported-by: NJohannes Weiner <jweiner@redhat.com> Acked-by: NRik van Riel <riel@redhat.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Acked-by: NJohannes Weiner <jweiner@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 25 5月, 2011 2 次提交
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由 Andrea Arcangeli 提交于
We don't need to hold the mmmap_sem through mem_cgroup_newpage_charge(), the mmap_sem is only hold for keeping the vma stable and we don't need the vma stable anymore after we return from alloc_hugepage_vma(). Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Peter Zijlstra 提交于
Straightforward conversion of anon_vma->lock to a mutex. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: NHugh Dickins <hughd@google.com> Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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: Nick Piggin <npiggin@kernel.dk> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 29 4月, 2011 1 次提交
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由 Andrea Arcangeli 提交于
The huge_memory.c THP page fault was allowed to run if vm_ops was null (which would succeed for /dev/zero MAP_PRIVATE, as the f_op->mmap wouldn't setup a special vma->vm_ops and it would fallback to regular anonymous memory) but other THP logics weren't fully activated for vmas with vm_file not NULL (/dev/zero has a not NULL vma->vm_file). So this removes the vm_file checks so that /dev/zero also can safely use THP (the other albeit safer approach to fix this bug would have been to prevent the THP initial page fault to run if vm_file was set). After removing the vm_file checks, this also makes huge_memory.c stricter in khugepaged for the DEBUG_VM=y case. It doesn't replace the vm_file check with a is_pfn_mapping check (but it keeps checking for VM_PFNMAP under VM_BUG_ON) because for a is_cow_mapping() mapping VM_PFNMAP should only be allowed to exist before the first page fault, and in turn when vma->anon_vma is null (so preventing khugepaged registration). So I tend to think the previous comment saying if vm_file was set, VM_PFNMAP might have been set and we could still be registered in khugepaged (despite anon_vma was not NULL to be registered in khugepaged) was too paranoid. The is_linear_pfn_mapping check is also I think superfluous (as described by comment) but under DEBUG_VM it is safe to stay. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=33682Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Reported-by: NCaspar Zhang <bugs@casparzhang.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Acked-by: NRik van Riel <riel@redhat.com> Cc: <stable@kernel.org> [2.6.38.x] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 15 4月, 2011 2 次提交
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由 Ben Hutchings 提交于
The conventional format for boolean attributes in sysfs is numeric ("0" or "1" followed by new-line). Any boolean attribute can then be read and written using a generic function. Using the strings "yes [no]", "[yes] no" (read), "yes" and "no" (write) will frustrate this. [akpm@linux-foundation.org: use kstrtoul()] [akpm@linux-foundation.org: test_bit() doesn't return 1/0, per Neil] Signed-off-by: NBen Hutchings <ben@decadent.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Tested-by: NDavid Rientjes <rientjes@google.com> Cc: NeilBrown <neilb@suse.de> Cc: <stable@kernel.org> [2.6.38.x] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andi Kleen 提交于
I found it difficult to make sense of transparent huge pages without having any counters for its actions. Add some counters to vmstat for allocation of transparent hugepages and fallback to smaller pages. Optional patch, but useful for development and understanding the system. Contains improvements from Andrea Arcangeli and Johannes Weiner [akpm@linux-foundation.org: coding-style fixes] [hannes@cmpxchg.org: fix vmstat_text[] entries] Signed-off-by: NAndi Kleen <ak@linux.intel.com> Acked-by: NAndrea Arcangeli <aarcange@redhat.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 23 3月, 2011 1 次提交
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由 Andi Kleen 提交于
Pass __GFP_OTHER_NODE for transparent hugepages NUMA allocations done by the hugepages daemon. This way the low level accounting for local versus remote pages works correctly. Contains improvements from Andrea Arcangeli [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NAndi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 14 3月, 2011 1 次提交
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由 Hugh Dickins 提交于
THP's collapse_huge_page() has an understandable but ugly difference in when its huge page is allocated: inside if NUMA but outside if not. It's hardly surprising that the memcg failure path forgot that, freeing the page in the non-NUMA case, then hitting a VM_BUG_ON in get_page() (or even worse, using the freed page). Signed-off-by: NHugh Dickins <hughd@google.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 05 3月, 2011 3 次提交
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由 Andi Kleen 提交于
Pass down the correct node for a transparent hugepage allocation. Most callers continue to use the current node, however the hugepaged daemon now uses the previous node of the first to be collapsed page instead. This ensures that khugepaged does not mess up local memory for an existing process which uses local policy. The choice of node is somewhat primitive currently: it just uses the node of the first page in the pmd range. An alternative would be to look at multiple pages and use the most popular node. I used the simplest variant for now which should work well enough for the case of all pages being on the same node. [akpm@linux-foundation.org: coding-style fixes] Acked-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndi Kleen <ak@linux.intel.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andi Kleen 提交于
This makes a difference for LOCAL policy, where the node cannot be determined from the policy itself, but has to be gotten from the original page. Acked-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndi Kleen <ak@linux.intel.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andi Kleen 提交于
Currently alloc_pages_vma() always uses the local node as policy node for the LOCAL policy. Pass this node down as an argument instead. No behaviour change from this patch, but will be needed for followons. Acked-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndi Kleen <ak@linux.intel.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 16 2月, 2011 1 次提交
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由 Andrea Arcangeli 提交于
Transparent hugepages can only be created if rmap is fully functional. So we must prevent hugepages to be created while is_vma_temporary_stack() is true. This also optmizes away some harmless but unnecessary setting of khugepaged_scan.address and it switches some BUG_ON to VM_BUG_ON. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Acked-by: NRik van Riel <riel@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 2月, 2011 1 次提交
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由 KAMEZAWA Hiroyuki 提交于
mem_cgroup_uncharge_page() should be called in all failure cases after mem_cgroup_charge_newpage() is called in huge_memory.c::collapse_huge_page() [ 4209.076861] BUG: Bad page state in process khugepaged pfn:1e9800 [ 4209.077601] page:ffffea0006b14000 count:0 mapcount:0 mapping: (null) index:0x2800 [ 4209.078674] page flags: 0x40000000004000(head) [ 4209.079294] pc:ffff880214a30000 pc->flags:2146246697418756 pc->mem_cgroup:ffffc9000177a000 [ 4209.082177] (/A) [ 4209.082500] Pid: 31, comm: khugepaged Not tainted 2.6.38-rc3-mm1 #1 [ 4209.083412] Call Trace: [ 4209.083678] [<ffffffff810f4454>] ? bad_page+0xe4/0x140 [ 4209.084240] [<ffffffff810f53e6>] ? free_pages_prepare+0xd6/0x120 [ 4209.084837] [<ffffffff8155621d>] ? rwsem_down_failed_common+0xbd/0x150 [ 4209.085509] [<ffffffff810f5462>] ? __free_pages_ok+0x32/0xe0 [ 4209.086110] [<ffffffff810f552b>] ? free_compound_page+0x1b/0x20 [ 4209.086699] [<ffffffff810fad6c>] ? __put_compound_page+0x1c/0x30 [ 4209.087333] [<ffffffff810fae1d>] ? put_compound_page+0x4d/0x200 [ 4209.087935] [<ffffffff810fb015>] ? put_page+0x45/0x50 [ 4209.097361] [<ffffffff8113f779>] ? khugepaged+0x9e9/0x1430 [ 4209.098364] [<ffffffff8107c870>] ? autoremove_wake_function+0x0/0x40 [ 4209.099121] [<ffffffff8113ed90>] ? khugepaged+0x0/0x1430 [ 4209.099780] [<ffffffff8107c236>] ? kthread+0x96/0xa0 [ 4209.100452] [<ffffffff8100dda4>] ? kernel_thread_helper+0x4/0x10 [ 4209.101214] [<ffffffff8107c1a0>] ? kthread+0x0/0xa0 [ 4209.101842] [<ffffffff8100dda0>] ? kernel_thread_helper+0x0/0x10 Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 03 2月, 2011 1 次提交
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由 Jin Dongming 提交于
When the tail page of THP is poisoned, the head page will be poisoned too. And the wrong address, address of head page, will be sent with sigbus always. So when the poisoned page is used by Guest OS which is running on KVM, after the address changing(hva->gpa) by qemu, the unexpected process on Guest OS will be killed by sigbus. What we expected is that the process using the poisoned tail page could be killed on Guest OS, but not that the process using the healthy head page is killed. Since it is not good to poison the healthy page, avoid poisoning other than the page which is really poisoned. (While we poison all pages in a huge page in case of hugetlb, we can do this for THP thanks to split_huge_page().) Here we fix two parts: 1. Isolate the poisoned page only to make sure the reported address is the address of poisoned page. 2. make the poisoned page work as the poisoned regular page. [akpm@linux-foundation.org: fix spello in comment] Signed-off-by: NJin Dongming <jin.dongming@np.css.fujitsu.com> Reviewed-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 21 1月, 2011 2 次提交
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由 KAMEZAWA Hiroyuki 提交于
Now, under THP: at charge: - PageCgroupUsed bit is set to all page_cgroup on a hugepage. ....set to 512 pages. at uncharge - PageCgroupUsed bit is unset on the head page. So, some pages will remain with "Used" bit. This patch fixes that Used bit is set only to the head page. Used bits for tail pages will be set at splitting if necessary. This patch adds this lock order: compound_lock() -> page_cgroup_move_lock(). [akpm@linux-foundation.org: fix warning] Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
Two users reported THP-related crashes on 32-bit x86 machines. Their oops reports indicated an invalid pte, and subsequent code inspection showed that the highpte is actually used after unmap. The fix is to unmap the pte only after all operations against it are finished. Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Reported-by: NIlya Dryomov <idryomov@gmail.com> Reported-by: Nwerner <w.landgraf@ru.ru> Cc: Andrea Arcangeli <aarcange@redhat.com> Tested-by: NIlya Dryomov <idryomov@gmail.com> Tested-by: Steven Rostedt <rostedt@goodmis.org Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 14 1月, 2011 11 次提交
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由 Andrea Arcangeli 提交于
MADV_HUGEPAGE and MADV_NOHUGEPAGE were fully effective only if run after mmap and before touching the memory. While this is enough for most usages, it's little effort to make madvise more dynamic at runtime on an existing mapping by making khugepaged aware about madvise. MADV_HUGEPAGE: register in khugepaged immediately without waiting a page fault (that may not ever happen if all pages are already mapped and the "enabled" knob was set to madvise during the initial page faults). MADV_NOHUGEPAGE: skip vmas marked VM_NOHUGEPAGE in khugepaged to stop collapsing pages where not needed. [akpm@linux-foundation.org: tweak comment] Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
Add madvise MADV_NOHUGEPAGE to mark regions that are not important to be hugepage backed. Return -EINVAL if the vma is not of an anonymous type, or the feature isn't built into the kernel. Never silently return success. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rik van Riel 提交于
Count each transparent hugepage as HPAGE_PMD_NR pages in the LRU statistics, so the Active(anon) and Inactive(anon) statistics in /proc/meminfo are correct. Signed-off-by: NRik van Riel <riel@redhat.com> Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rik van Riel 提交于
On small systems, the extra memory used by the anti-fragmentation memory reserve and simply because huge pages are smaller than large pages can easily outweigh the benefits of less TLB misses. A less obvious concern is if run on a NUMA machine with asymmetric node sizes and one of them is very small. The reserve could make the node unusable. In case of the crashdump kernel, OOMs have been observed due to the anti-fragmentation memory reserve taking up a large fraction of the crashdump image. This patch disables transparent hugepages on systems with less than 1GB of RAM, but the hugepage subsystem is fully initialized so administrators can enable THP through /sys if desired. Signed-off-by: NRik van Riel <riel@redhat.com> Acked-by: NAvi Kiviti <avi@redhat.com> Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
It's unclear why schedule friendly kernel threads can't be taken away by the CPU through the scheduler itself. It's safer to stop them as they can trigger memory allocation, if kswapd also freezes itself to avoid generating I/O they have too. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
For GRU and EPT, we need gup-fast to set referenced bit too (this is why it's correct to return 0 when shadow_access_mask is zero, it requires gup-fast to set the referenced bit). qemu-kvm access already sets the young bit in the pte if it isn't zero-copy, if it's zero copy or a shadow paging EPT minor fault we relay on gup-fast to signal the page is in use... We also need to check the young bits on the secondary pagetables for NPT and not nested shadow mmu as the data may never get accessed again by the primary pte. Without this closer accuracy, we'd have to remove the heuristic that avoids collapsing hugepages in hugepage virtual regions that have not even a single subpage in use. ->test_young is full backwards compatible with GRU and other usages that don't have young bits in pagetables set by the hardware and that should nuke the secondary mmu mappings when ->clear_flush_young runs just like EPT does. Removing the heuristic that checks the young bit in khugepaged/collapse_huge_page completely isn't so bad either probably but I thought it was worth it and this makes it reliable. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
Archs implementing Transparent Hugepage Support must implement a function called has_transparent_hugepage to be sure the virtual or physical CPU supports Transparent Hugepages. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
An huge pmd can only be mapped if the corresponding 2M virtual range is fully contained in the vma. At times the VM calls split_vma twice, if the first split_vma succeeds and the second fail, the first split_vma remains in effect and it's not rolled back. For split_vma or vma_adjust to fail an allocation failure is needed so it's a very unlikely event (the out of memory killer would normally fire before any allocation failure is visible to kernel and userland and if an out of memory condition happens it's unlikely to happen exactly here). Nevertheless it's safer to ensure that no huge pmd can be left around if the vma is adjusted in a way that can't fit hugepages anymore at the new vm_start/vm_end address. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
Allow to choose between the always|madvise default for page faults and khugepaged at config time. madvise guarantees zero risk of higher memory footprint for applications (applications using madvise(MADV_HUGEPAGE) won't risk to use any more memory by backing their virtual regions with hugepages). Initially set the default to N and don't depend on EMBEDDED. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
This tries to be more friendly to filesystem in userland, with userland backends that allocate memory in the I/O paths and that could deadlock if khugepaged holds the mmap_sem write mode of the userland backend while allocating memory. Memory allocation may wait for writeback I/O completion from the daemon that may be blocked in the mmap_sem read mode if a page fault happens and the daemon wasn't using mlock for the memory required for the I/O submission and completion. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
It's mostly a matter of replacing alloc_pages with alloc_pages_vma after introducing alloc_pages_vma. khugepaged needs special handling as the allocation has to happen inside collapse_huge_page where the vma is known and an error has to be returned to the outer loop to sleep alloc_sleep_millisecs in case of failure. But it retains the more efficient logic of handling allocation failures in khugepaged in case of CONFIG_NUMA=n. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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