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2012-10-09mm/memblock: cleanup early_node_map[] related commentsWanpeng Li
Commit 0ee332c14518 ("memblock: Kill early_node_map[]") removed early_node_map[]. Clean up the comments to comply with that change. Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm/memblock: use existing interface to set nidWanpeng Li
Use the existing interface function to set the NUMA node ID (NID) for the regions, either memory or reserved region. Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09readahead: fault retry breaks mmap file read random detectionShaohua Li
.fault now can retry. The retry can break state machine of .fault. In filemap_fault, if page is miss, ra->mmap_miss is increased. In the second try, since the page is in page cache now, ra->mmap_miss is decreased. And these are done in one fault, so we can't detect random mmap file access. Add a new flag to indicate .fault is tried once. In the second try, skip ra->mmap_miss decreasing. The filemap_fault state machine is ok with it. I only tested x86, didn't test other archs, but looks the change for other archs is obvious, but who knows :) Signed-off-by: Shaohua Li <shaohua.li@fusionio.com> Cc: Rik van Riel <riel@redhat.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09memory-hotplug: fix pages missed by race rather than failingMinchan Kim
If race between allocation and isolation in memory-hotplug offline happens, some pages could be in MIGRATE_MOVABLE of free_list although the pageblock's migratetype of the page is MIGRATE_ISOLATE. The race could be detected by get_freepage_migratetype in __test_page_isolated_in_pageblock. If it is detected, now EBUSY gets bubbled all the way up and the hotplug operations fails. But better idea is instead of returning and failing memory-hotremove, move the free page to the correct list at the time it is detected. It could enhance memory-hotremove operation success ratio although the race is really rare. Suggested by Mel Gorman. [akpm@linux-foundation.org: small cleanup] Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09memory-hotplug: bug fix race between isolation and allocationMinchan Kim
Like below, memory-hotplug makes race between page-isolation and page-allocation so it can hit BUG_ON in __offline_isolated_pages. CPU A CPU B start_isolate_page_range set_migratetype_isolate spin_lock_irqsave(zone->lock) free_hot_cold_page(Page A) /* without zone->lock */ migratetype = get_pageblock_migratetype(Page A); /* * Page could be moved into MIGRATE_MOVABLE * of per_cpu_pages */ list_add_tail(&page->lru, &pcp->lists[migratetype]); set_pageblock_isolate move_freepages_block drain_all_pages /* Page A could be in MIGRATE_MOVABLE of free_list. */ check_pages_isolated __test_page_isolated_in_pageblock /* * We can't catch freed page which * is free_list[MIGRATE_MOVABLE] */ if (PageBuddy(page A)) pfn += 1 << page_order(page A); /* So, Page A could be allocated */ __offline_isolated_pages /* * BUG_ON hit or offline page * which is used by someone */ BUG_ON(!PageBuddy(page A)); This patch checks page's migratetype in freelist in __test_page_isolated_in_pageblock. So now __test_page_isolated_in_pageblock can check the page caused by above race and can fail of memory offlining. Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm: remain migratetype in freed pageMinchan Kim
The page allocator caches the pageblock information in page->private while it is in the PCP freelists but this is overwritten with the order of the page when freed to the buddy allocator. This patch stores the migratetype of the page in the page->index field so that it is available at all times when the page remain in free_list. This patch adds a new call site in __free_pages_ok so it might be overhead a bit but it's for high order allocation. So I believe damage isn't hurt. Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm: page_alloc: use get_freepage_migratetype() instead of page_private()Minchan Kim
The page allocator uses set_page_private and page_private for handling migratetype when it frees page. Let's replace them with [set|get] _freepage_migratetype to make it more clear. Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09cma: fix watermark checkingBartlomiej Zolnierkiewicz
* Add ALLOC_CMA alloc flag and pass it to [__]zone_watermark_ok() (from Minchan Kim). * During watermark check decrease available free pages number by free CMA pages number if necessary (unmovable allocations cannot use pages from CMA areas). Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09cma: count free CMA pagesBartlomiej Zolnierkiewicz
Add NR_FREE_CMA_PAGES counter to be later used for checking watermark in __zone_watermark_ok(). For simplicity and to avoid #ifdef hell make this counter always available (not only when CONFIG_CMA=y). [akpm@linux-foundation.org: use conventional migratetype naming] Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09cma: fix counting of isolated pagesBartlomiej Zolnierkiewicz
Isolated free pages shouldn't be accounted to NR_FREE_PAGES counter. Fix it by properly decreasing/increasing NR_FREE_PAGES counter in set_migratetype_isolate()/unset_migratetype_isolate() and removing counter adjustment for isolated pages from free_one_page() and split_free_page(). Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm: fix tracing in free_pcppages_bulk()Bartlomiej Zolnierkiewicz
page->private gets re-used in __free_one_page() to store page order (so trace_mm_page_pcpu_drain() may print order instead of migratetype) thus migratetype value must be cached locally. Fixes regression introduced in commit a7016235a61d ("mm: fix migratetype bug which slowed swapping"). This caused incorrect data to be attached to the mm_page_pcpu_drain trace event. [akpm@linux-foundation.org: add comment] Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: 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>
2012-10-09mm: cma: discard clean pages during contiguous allocation instead of migrationMinchan Kim
Drop clean cache pages instead of migration during alloc_contig_range() to minimise allocation latency by reducing the amount of migration that is necessary. It's useful for CMA because latency of migration is more important than evicting the background process's working set. In addition, as pages are reclaimed then fewer free pages for migration targets are required so it avoids memory reclaiming to get free pages, which is a contributory factor to increased latency. I measured elapsed time of __alloc_contig_migrate_range() which migrates 10M in 40M movable zone in QEMU machine. Before - 146ms, After - 7ms [akpm@linux-foundation.org: fix nommu build] Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Mel Gorman <mgorman@suse.de> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Rik van Riel <riel@redhat.com> Tested-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm: mmu_notifier: make the mmu_notifier srcu staticAndrea Arcangeli
The variable must be static especially given the variable name. s/RCU/SRCU/ over a few comments. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Haggai Eran <haggaie@mellanox.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09memory-hotplug: build zonelists when offlining pagesXishi Qiu
online_pages() does build_all_zonelists() and zone_pcp_update(), I think offline_pages() should do it too. When the zone has no memory to allocate, remove it from other nodes' zonelists. zone_batchsize() depends on zone's present pages, if zone's present pages are changed, zone's pcp should be updated. Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm: avoid taking rmap locks in move_ptes()Michel Lespinasse
During mremap(), the destination VMA is generally placed after the original vma in rmap traversal order: in move_vma(), we always have new_pgoff >= vma->vm_pgoff, and as a result new_vma->vm_pgoff >= vma->vm_pgoff unless vma_merge() merged the new vma with an adjacent one. When the destination VMA is placed after the original in rmap traversal order, we can avoid taking the rmap locks in move_ptes(). Essentially, this reintroduces the optimization that had been disabled in "mm anon rmap: remove anon_vma_moveto_tail". The difference is that we don't try to impose the rmap traversal order; instead we just rely on things being in the desired order in the common case and fall back to taking locks in the uncommon case. Also we skip the i_mmap_mutex in addition to the anon_vma lock: in both cases, the vmas are traversed in increasing vm_pgoff order with ties resolved in tree insertion order. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Daniel Santos <daniel.santos@pobox.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm anon rmap: in mremap, set the new vma's position before anon_vma_clone()Michel Lespinasse
anon_vma_clone() expects new_vma->vm_{start,end,pgoff} to be correctly set so that the new vma can be indexed on the anon interval tree. copy_vma() was failing to do that, which broke mremap(). Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Hugh Dickins <hughd@google.com> Tested-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm: add CONFIG_DEBUG_VM_RB build optionMichel Lespinasse
Add a CONFIG_DEBUG_VM_RB build option for the previously existing DEBUG_MM_RB code. Now that Andi Kleen modified it to avoid using recursive algorithms, we can expose it a bit more. Also extend this code to validate_mm() after stack expansion, and to check that the vma's start and last pgoffs have not changed since the nodes were inserted on the anon vma interval tree (as it is important that the nodes be reindexed after each such update). Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Daniel Santos <daniel.santos@pobox.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm rmap: remove vma_address check for address inside vmaMichel Lespinasse
In file and anon rmap, we use interval trees to find potentially relevant vmas and then call vma_address() to find the virtual address the given page might be found at in these vmas. vma_address() used to include a check that the returned address falls within the limits of the vma, but this check isn't necessary now that we always use interval trees in rmap: the interval tree just doesn't return any vmas which this check would find to be irrelevant. As a result, we can replace the use of -EFAULT error code (which then needed to be checked in every call site) with a VM_BUG_ON(). Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Daniel Santos <daniel.santos@pobox.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm anon rmap: replace same_anon_vma linked list with an interval tree.Michel Lespinasse
When a large VMA (anon or private file mapping) is first touched, which will populate its anon_vma field, and then split into many regions through the use of mprotect(), the original anon_vma ends up linking all of the vmas on a linked list. This can cause rmap to become inefficient, as we have to walk potentially thousands of irrelevent vmas before finding the one a given anon page might fall into. By replacing the same_anon_vma linked list with an interval tree (where each avc's interval is determined by its vma's start and last pgoffs), we can make rmap efficient for this use case again. While the change is large, all of its pieces are fairly simple. Most places that were walking the same_anon_vma list were looking for a known pgoff, so they can just use the anon_vma_interval_tree_foreach() interval tree iterator instead. The exception here is ksm, where the page's index is not known. It would probably be possible to rework ksm so that the index would be known, but for now I have decided to keep things simple and just walk the entirety of the interval tree there. When updating vma's that already have an anon_vma assigned, we must take care to re-index the corresponding avc's on their interval tree. This is done through the use of anon_vma_interval_tree_pre_update_vma() and anon_vma_interval_tree_post_update_vma(), which remove the avc's from their interval tree before the update and re-insert them after the update. The anon_vma stays locked during the update, so there is no chance that rmap would miss the vmas that are being updated. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Daniel Santos <daniel.santos@pobox.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm anon rmap: remove anon_vma_moveto_tailMichel Lespinasse
mremap() had a clever optimization where move_ptes() did not take the anon_vma lock to avoid a race with anon rmap users such as page migration. Instead, the avc's were ordered in such a way that the origin vma was always visited by rmap before the destination. This ordering and the use of page table locks rmap usage safe. However, we want to replace the use of linked lists in anon rmap with an interval tree, and this will make it harder to impose such ordering as the interval tree will always be sorted by the avc->vma->vm_pgoff value. For now, let's replace the anon_vma_moveto_tail() ordering function with proper anon_vma locking in move_ptes(). Once we have the anon interval tree in place, we will re-introduce an optimization to avoid taking these locks in the most common cases. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Daniel Santos <daniel.santos@pobox.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm: interval tree updatesMichel Lespinasse
Update the generic interval tree code that was introduced in "mm: replace vma prio_tree with an interval tree". Changes: - fixed 'endpoing' typo noticed by Andrew Morton - replaced include/linux/interval_tree_tmpl.h, which was used as a template (including it automatically defined the interval tree functions) with include/linux/interval_tree_generic.h, which only defines a preprocessor macro INTERVAL_TREE_DEFINE(), which itself defines the interval tree functions when invoked. Now that is a very long macro which is unfortunate, but it does make the usage sites (lib/interval_tree.c and mm/interval_tree.c) a bit nicer than previously. - make use of RB_DECLARE_CALLBACKS() in the INTERVAL_TREE_DEFINE() macro, instead of duplicating that code in the interval tree template. - replaced vma_interval_tree_add(), which was actually handling the nonlinear and interval tree cases, with vma_interval_tree_insert_after() which handles only the interval tree case and has an API that is more consistent with the other interval tree handling functions. The nonlinear case is now handled explicitly in kernel/fork.c dup_mmap(). Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Daniel Santos <daniel.santos@pobox.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09kmemleak: use rbtree instead of prio treeMichel Lespinasse
kmemleak uses a tree where each node represents an allocated memory object in order to quickly find out what object a given address is part of. However, the objects don't overlap, so rbtrees are a better choice than prio tree for this use. They are both faster and have lower memory overhead. Tested by booting a kernel with kmemleak enabled, loading the kmemleak_test module, and looking for the expected messages. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw2@infradead.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm: replace vma prio_tree with an interval treeMichel Lespinasse
Implement an interval tree as a replacement for the VMA prio_tree. The algorithms are similar to lib/interval_tree.c; however that code can't be directly reused as the interval endpoints are not explicitly stored in the VMA. So instead, the common algorithm is moved into a template and the details (node type, how to get interval endpoints from the node, etc) are filled in using the C preprocessor. Once the interval tree functions are available, using them as a replacement to the VMA prio tree is a relatively simple, mechanical job. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: make MADV_HUGEPAGE check for mm->def_flagsGerald Schaefer
This adds a check to hugepage_madvise(), to refuse MADV_HUGEPAGE if VM_NOHUGEPAGE is set in mm->def_flags. On s390, the VM_NOHUGEPAGE flag will be set in mm->def_flags for kvm processes, to prevent any future thp mappings. In order to also prevent MADV_HUGEPAGE on such an mm, hugepage_madvise() should check mm->def_flags. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Hillf Danton <dhillf@gmail.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>
2012-10-09thp: introduce pmdp_invalidate()Gerald Schaefer
On s390, a valid page table entry must not be changed while it is attached to any CPU. So instead of pmd_mknotpresent() and set_pmd_at(), an IDTE operation would be necessary there. This patch introduces the pmdp_invalidate() function, to allow architecture-specific implementations. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Hillf Danton <dhillf@gmail.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>
2012-10-09thp: remove assumptions on pgtable_t typeGerald Schaefer
The thp page table pre-allocation code currently assumes that pgtable_t is of type "struct page *". This may not be true for all architectures, so this patch removes that assumption by replacing the functions prepare_pmd_huge_pte() and get_pmd_huge_pte() with two new functions that can be defined architecture-specific. It also removes two VM_BUG_ON checks for page_count() and page_mapcount() operating on a pgtable_t. Apart from the VM_BUG_ON removal, there will be no functional change introduced by this patch. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Hillf Danton <dhillf@gmail.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>
2012-10-09thp, x86: introduce HAVE_ARCH_TRANSPARENT_HUGEPAGEGerald Schaefer
Cleanup patch in preparation for transparent hugepage support on s390. Adding new architectures to the TRANSPARENT_HUGEPAGE config option can make the "depends" line rather ugly, like "depends on (X86 || (S390 && 64BIT)) && MMU". This patch adds a HAVE_ARCH_TRANSPARENT_HUGEPAGE instead. x86 already has MMU "def_bool y", so the MMU check is superfluous there and HAVE_ARCH_TRANSPARENT_HUGEPAGE can be selected in arch/x86/Kconfig. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Hillf Danton <dhillf@gmail.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>
2012-10-09mm: fix potential anon_vma locking issue in mprotect()Michel Lespinasse
Fix an anon_vma locking issue in the following situation: - vma has no anon_vma - next has an anon_vma - vma is being shrunk / next is being expanded, due to an mprotect call We need to take next's anon_vma lock to avoid races with rmap users (such as page migration) while next is being expanded. Signed-off-by: Michel Lespinasse <walken@google.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: remove unnecessary set_recommended_min_free_kbytesXiao Guangrong
Since it is called in start_khugepaged Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: use khugepaged_enabled to remove duplicate codeXiao Guangrong
Use khugepaged_enabled to see whether thp is enabled Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: remove khugepaged_loopXiao Guangrong
Merge khugepaged_loop into khugepaged Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: introduce khugepaged_prealloc_page and khugepaged_alloc_pageXiao Guangrong
They are used to abstract the difference between NUMA enabled and NUMA disabled to make the code more readable Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: release page in page pre-alloc pathXiao Guangrong
If NUMA is enabled, we can release the page in the page pre-alloc operation, then the CONFIG_NUMA dependent code can be reduced Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: merge page pre-alloc in khugepaged_loop into khugepaged_do_scanXiao Guangrong
There are two pre-alloc operations in these two function, the different is: - it allows to sleep if page alloc fail in khugepaged_loop - it exits immediately if page alloc fail in khugepaged_do_scan Actually, in khugepaged_do_scan, we can allow the pre-alloc to sleep on the first failure, then the operation in khugepaged_loop can be removed Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: remove some code depend on CONFIG_NUMAXiao Guangrong
If NUMA is disabled, hpage is used as page pre-alloc, so there are two cases for hpage: - it is !NULL, means the page is not consumed otherwise, - the page has been consumed If NUMA is enabled, hpage is just used as alloc-fail indicator which is not a real page, NULL means not fail triggered. So, we can release the page only if !IS_ERR_OR_NULL Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: remove wake_up_interruptible in the exit pathXiao Guangrong
Add the check of kthread_should_stop() to the conditions which are used to wakeup on khugepaged_wait, then kthread_stop is enough to let the thread exit Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: remove unnecessary khugepaged_thread checkXiao Guangrong
Now, khugepaged creation and cancel are completely serial under the protection of khugepaged_mutex, it is impossible that many khugepaged entities are running Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: move khugepaged_mutex out of khugepagedXiao Guangrong
Currently, hugepaged_mutex is used really complexly and hard to understand, actually, it is just used to serialize start_khugepaged and khugepaged for these reasons: - khugepaged_thread is shared between them - the thp disable path (echo never > transparent_hugepage/enabled) is nonblocking, so we need to protect khugepaged_thread to get a stable running state These can be avoided by: - use the lock to serialize the thread creation and cancel - thp disable path can not finised until the thread exits Then khugepaged_thread is fully controlled by start_khugepaged, khugepaged will be happy without the lock Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: remove unnecessary check in start_khugepagedXiao Guangrong
The check is unnecessary since if mm_slot_cache or mm_slots_hash initialize failed, no sysfs interface will be created Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09thp: fix the count of THP_COLLAPSE_ALLOCXiao Guangrong
THP_COLLAPSE_ALLOC is double counted if NUMA is disabled since it has already been calculated in khugepaged_alloc_hugepage Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm: adjust final #endif position in mm/internal.hMichel Lespinasse
Make sure the #endif that terminates the standard #ifndef / #define / #endif construct gets labeled, and gets positioned at the end of the file as is normally the case. Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm: hugetlb: add arch hook for clearing page flags before entering poolWill Deacon
The core page allocator ensures that page flags are zeroed when freeing pages via free_pages_check. A number of architectures (ARM, PPC, MIPS) rely on this property to treat new pages as dirty with respect to the data cache and perform the appropriate flushing before mapping the pages into userspace. This can lead to cache synchronisation problems when using hugepages, since the allocator keeps its own pool of pages above the usual page allocator and does not reset the page flags when freeing a page into the pool. This patch adds a new architecture hook, arch_clear_hugepage_flags, so that architectures which rely on the page flags being in a particular state for fresh allocations can adjust the flags accordingly when a page is freed into the pool. Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Michal Hocko <mhocko@suse.cz> 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>
2012-10-09oom: remove deprecated oom_adjDavidlohr Bueso
The deprecated /proc/<pid>/oom_adj is scheduled for removal this month. Signed-off-by: Davidlohr Bueso <dave@gnu.org> Acked-by: David Rientjes <rientjes@google.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>
2012-10-09mm/vmscan: fix error number for failed kthreadGavin Shan
Fix the return value while failing to create the kswapd kernel thread. Also, the error message is prioritized as KERN_ERR. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm/mmu_notifier: init notifier if necessaryGavin Shan
While registering MMU notifier, new instance of MMU notifier_mm will be allocated and later free'd if currrent mm_struct's MMU notifier_mm has been initialized. That causes some overhead. The patch tries to elominate that. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Avi Kivity <avi@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Sagi Grimberg <sagig@mellanox.co.il> Cc: Haggai Eran <haggaie@mellanox.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mm: mmu_notifier: have mmu_notifiers use a global SRCU so they may safely ↵Sagi Grimberg
schedule With an RCU based mmu_notifier implementation, any callout to mmu_notifier_invalidate_range_{start,end}() or mmu_notifier_invalidate_page() would not be allowed to call schedule() as that could potentially allow a modification to the mmu_notifier structure while it is currently being used. Since srcu allocs 4 machine words per instance per cpu, we may end up with memory exhaustion if we use srcu per mm. So all mms share a global srcu. Note that during large mmu_notifier activity exit & unregister paths might hang for longer periods, but it is tolerable for current mmu_notifier clients. Signed-off-by: Sagi Grimberg <sagig@mellanox.co.il> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Haggai Eran <haggaie@mellanox.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mempolicy: fix a memory corruption by refcount imbalance in alloc_pages_vma()Mel Gorman
Commit cc9a6c877661 ("cpuset: mm: reduce large amounts of memory barrier related damage v3") introduced a potential memory corruption. shmem_alloc_page() uses a pseudo vma and it has one significant unique combination, vma->vm_ops=NULL and vma->policy->flags & MPOL_F_SHARED. get_vma_policy() does NOT increase a policy ref when vma->vm_ops=NULL and mpol_cond_put() DOES decrease a policy ref when a policy has MPOL_F_SHARED. Therefore, when a cpuset update race occurs, alloc_pages_vma() falls in 'goto retry_cpuset' path, decrements the reference count and frees the policy prematurely. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Christoph Lameter <cl@linux.com> Cc: Josh Boyer <jwboyer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mempolicy: fix refcount leak in mpol_set_shared_policy()KOSAKI Motohiro
When shared_policy_replace() fails to allocate new->policy is not freed correctly by mpol_set_shared_policy(). The problem is that shared mempolicy code directly call kmem_cache_free() in multiple places where it is easy to make a mistake. This patch creates an sp_free wrapper function and uses it. The bug was introduced pre-git age (IOW, before 2.6.12-rc2). [mgorman@suse.de: Editted changelog] Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Christoph Lameter <cl@linux.com> Cc: Josh Boyer <jwboyer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mempolicy: fix a race in shared_policy_replace()Mel Gorman
shared_policy_replace() use of sp_alloc() is unsafe. 1) sp_node cannot be dereferenced if sp->lock is not held and 2) another thread can modify sp_node between spin_unlock for allocating a new sp node and next spin_lock. The bug was introduced before 2.6.12-rc2. Kosaki's original patch for this problem was to allocate an sp node and policy within shared_policy_replace and initialise it when the lock is reacquired. I was not keen on this approach because it partially duplicates sp_alloc(). As the paths were sp->lock is taken are not that performance critical this patch converts sp->lock to sp->mutex so it can sleep when calling sp_alloc(). [kosaki.motohiro@jp.fujitsu.com: Original patch] Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Christoph Lameter <cl@linux.com> Cc: Josh Boyer <jwboyer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09mempolicy: remove mempolicy sharingKOSAKI Motohiro
Dave Jones' system call fuzz testing tool "trinity" triggered the following bug error with slab debugging enabled ============================================================================= BUG numa_policy (Not tainted): Poison overwritten ----------------------------------------------------------------------------- INFO: 0xffff880146498250-0xffff880146498250. First byte 0x6a instead of 0x6b INFO: Allocated in mpol_new+0xa3/0x140 age=46310 cpu=6 pid=32154 __slab_alloc+0x3d3/0x445 kmem_cache_alloc+0x29d/0x2b0 mpol_new+0xa3/0x140 sys_mbind+0x142/0x620 system_call_fastpath+0x16/0x1b INFO: Freed in __mpol_put+0x27/0x30 age=46268 cpu=6 pid=32154 __slab_free+0x2e/0x1de kmem_cache_free+0x25a/0x260 __mpol_put+0x27/0x30 remove_vma+0x68/0x90 exit_mmap+0x118/0x140 mmput+0x73/0x110 exit_mm+0x108/0x130 do_exit+0x162/0xb90 do_group_exit+0x4f/0xc0 sys_exit_group+0x17/0x20 system_call_fastpath+0x16/0x1b INFO: Slab 0xffffea0005192600 objects=27 used=27 fp=0x (null) flags=0x20000000004080 INFO: Object 0xffff880146498250 @offset=592 fp=0xffff88014649b9d0 The problem is that the structure is being prematurely freed due to a reference count imbalance. In the following case mbind(addr, len) should replace the memory policies of both vma1 and vma2 and thus they will become to share the same mempolicy and the new mempolicy will have the MPOL_F_SHARED flag. +-------------------+-------------------+ | vma1 | vma2(shmem) | +-------------------+-------------------+ | | addr addr+len alloc_pages_vma() uses get_vma_policy() and mpol_cond_put() pair for maintaining the mempolicy reference count. The current rule is that get_vma_policy() only increments refcount for shmem VMA and mpol_conf_put() only decrements refcount if the policy has MPOL_F_SHARED. In above case, vma1 is not shmem vma and vma->policy has MPOL_F_SHARED! The reference count will be decreased even though was not increased whenever alloc_page_vma() is called. This has been broken since commit [52cd3b07: mempolicy: rework mempolicy Reference Counting] in 2008. There is another serious bug with the sharing of memory policies. Currently, mempolicy rebind logic (it is called from cpuset rebinding) ignores a refcount of mempolicy and override it forcibly. Thus, any mempolicy sharing may cause mempolicy corruption. The bug was introduced by commit [68860ec1: cpusets: automatic numa mempolicy rebinding]. Ideally, the shared policy handling would be rewritten to either properly handle COW of the policy structures or at least reference count MPOL_F_SHARED based exclusively on information within the policy. However, this patch takes the easier approach of disabling any policy sharing between VMAs. Each new range allocated with sp_alloc will allocate a new policy, set the reference count to 1 and drop the reference count of the old policy. This increases the memory footprint but is not expected to be a major problem as mbind() is unlikely to be used for fine-grained ranges. It is also inefficient because it means we allocate a new policy even in cases where mbind_range() could use the new_policy passed to it. However, it is more straight-forward and the change should be invisible to the user. [mgorman@suse.de: Edited changelog] Reported-by: Dave Jones <davej@redhat.com>, Cc: Christoph Lameter <cl@linux.com>, Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Josh Boyer <jwboyer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>