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* thp: close race between split and zap huge pagesKirill A. Shutemov2014-04-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sasha Levin has reported two THP BUGs[1][2]. I believe both of them have the same root cause. Let's look to them one by one. The first bug[1] is "kernel BUG at mm/huge_memory.c:1829!". It's BUG_ON(mapcount != page_mapcount(page)) in __split_huge_page(). From my testing I see that page_mapcount() is higher than mapcount here. I think it happens due to race between zap_huge_pmd() and page_check_address_pmd(). page_check_address_pmd() misses PMD which is under zap: CPU0 CPU1 zap_huge_pmd() pmdp_get_and_clear() __split_huge_page() anon_vma_interval_tree_foreach() __split_huge_page_splitting() page_check_address_pmd() mm_find_pmd() /* * We check if PMD present without taking ptl: no * serialization against zap_huge_pmd(). We miss this PMD, * it's not accounted to 'mapcount' in __split_huge_page(). */ pmd_present(pmd) == 0 BUG_ON(mapcount != page_mapcount(page)) // CRASH!!! page_remove_rmap(page) atomic_add_negative(-1, &page->_mapcount) The second bug[2] is "kernel BUG at mm/huge_memory.c:1371!". It's VM_BUG_ON_PAGE(!PageHead(page), page) in zap_huge_pmd(). This happens in similar way: CPU0 CPU1 zap_huge_pmd() pmdp_get_and_clear() page_remove_rmap(page) atomic_add_negative(-1, &page->_mapcount) __split_huge_page() anon_vma_interval_tree_foreach() __split_huge_page_splitting() page_check_address_pmd() mm_find_pmd() pmd_present(pmd) == 0 /* The same comment as above */ /* * No crash this time since we already decremented page->_mapcount in * zap_huge_pmd(). */ BUG_ON(mapcount != page_mapcount(page)) /* * We split the compound page here into small pages without * serialization against zap_huge_pmd() */ __split_huge_page_refcount() VM_BUG_ON_PAGE(!PageHead(page), page); // CRASH!!! So my understanding the problem is pmd_present() check in mm_find_pmd() without taking page table lock. The bug was introduced by me commit with commit 117b0791ac42. Sorry for that. :( Let's open code mm_find_pmd() in page_check_address_pmd() and do the check under page table lock. Note that __page_check_address() does the same for PTE entires if sync != 0. I've stress tested split and zap code paths for 36+ hours by now and don't see crashes with the patch applied. Before it took <20 min to trigger the first bug and few hours for second one (if we ignore first). [1] https://lkml.kernel.org/g/<53440991.9090001@oracle.com> [2] https://lkml.kernel.org/g/<5310C56C.60709@oracle.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Bob Liu <lliubbo@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michel Lespinasse <walken@google.com> Cc: Dave Jones <davej@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> [3.13+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix new kernel-doc warning in filemap.cRandy Dunlap2014-04-18
| | | | | | | | | | Fix new kernel-doc warning in mm/filemap.c: Warning(mm/filemap.c:2600): Excess function parameter 'ppos' description in '__generic_file_aio_write' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()Mizuma, Masayoshi2014-04-18
| | | | | | | | | | | | | | | | soft lockup in freeing gigantic hugepage fixed in commit 55f67141a892 "mm: hugetlb: fix softlockup when a large number of hugepages are freed." can happen in return_unused_surplus_pages(), so let's fix it. Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmscan: reclaim_clean_pages_from_list() must use mod_zone_page_state()Christoph Lameter2014-04-18
| | | | | | | | | | | | | | | Seems to be called with preemption enabled. Therefore it must use mod_zone_page_state instead. Signed-off-by: Christoph Lameter <cl@linux.com> Reported-by: Grygorii Strashko <grygorii.strashko@ti.com> Tested-by: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Tejun Heo <tj@kernel.org> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: 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: Initialize error in shmem_file_aio_read()Geert Uytterhoeven2014-04-13
| | | | | | | | | | | | | | | | | Some versions of gcc even warn about it: mm/shmem.c: In function ‘shmem_file_aio_read’: mm/shmem.c:1414: warning: ‘error’ may be used uninitialized in this function If the loop is aborted during the first iteration by one of the two first break statements, error will be uninitialized. Introduced by commit 6e58e79db8a1 ("introduce copy_page_to_iter, kill loop over iovec in generic_file_aio_read()"). Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'slab/next' of ↵Linus Torvalds2014-04-13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux Pull slab changes from Pekka Enberg: "The biggest change is byte-sized freelist indices which reduces slab freelist memory usage: https://lkml.org/lkml/2013/12/2/64" * 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux: mm: slab/slub: use page->list consistently instead of page->lru mm/slab.c: cleanup outdated comments and unify variables naming slab: fix wrongly used macro slub: fix high order page allocation problem with __GFP_NOFAIL slab: Make allocations with GFP_ZERO slightly more efficient slab: make more slab management structure off the slab slab: introduce byte sized index for the freelist of a slab slab: restrict the number of objects in a slab slab: introduce helper functions to get/set free object slab: factor out calculate nr objects in cache_estimate
| * mm: slab/slub: use page->list consistently instead of page->lruDave Hansen2014-04-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'struct page' has two list_head fields: 'lru' and 'list'. Conveniently, they are unioned together. This means that code can use them interchangably, which gets horribly confusing like with this nugget from slab.c: > list_del(&page->lru); > if (page->active == cachep->num) > list_add(&page->list, &n->slabs_full); This patch makes the slab and slub code use page->lru universally instead of mixing ->list and ->lru. So, the new rule is: page->lru is what the you use if you want to keep your page on a list. Don't like the fact that it's not called ->list? Too bad. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| * mm/slab.c: cleanup outdated comments and unify variables namingJianyu Zhan2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | As time goes, the code changes a lot, and this leads to that some old-days comments scatter around , which instead of faciliating understanding, but make more confusion. So this patch cleans up them. Also, this patch unifies some variables naming. Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Jianyu Zhan <nasa4836@gmail.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| * slub: fix high order page allocation problem with __GFP_NOFAILJoonsoo Kim2014-03-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SLUB already try to allocate high order page with clearing __GFP_NOFAIL. But, when allocating shadow page for kmemcheck, it missed clearing the flag. This trigger WARN_ON_ONCE() reported by Christian Casteyde. https://bugzilla.kernel.org/show_bug.cgi?id=65991 https://lkml.org/lkml/2013/12/3/764 This patch fix this situation by using same allocation flag as original allocation. Reported-by: Christian Casteyde <casteyde.christian@free.fr> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| * slab: Make allocations with GFP_ZERO slightly more efficientJoe Perches2014-02-08
| | | | | | | | | | | | | | | | | | | | Use the likely mechanism already around valid pointer tests to better choose when to memset to 0 allocations with __GFP_ZERO Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| * slab: make more slab management structure off the slabJoonsoo Kim2014-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now, the size of the freelist for the slab management diminish, so that the on-slab management structure can waste large space if the object of the slab is large. Consider a 128 byte sized slab. If on-slab is used, 31 objects can be in the slab. The size of the freelist for this case would be 31 bytes so that 97 bytes, that is, more than 75% of object size, are wasted. In a 64 byte sized slab case, no space is wasted if we use on-slab. So set off-slab determining constraint to 128 bytes. Acked-by: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| * slab: introduce byte sized index for the freelist of a slabJoonsoo Kim2014-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the freelist of a slab consist of unsigned int sized indexes. Since most of slabs have less number of objects than 256, large sized indexes is needless. For example, consider the minimum kmalloc slab. It's object size is 32 byte and it would consist of one page, so 256 indexes through byte sized index are enough to contain all possible indexes. There can be some slabs whose object size is 8 byte. We cannot handle this case with byte sized index, so we need to restrict minimum object size. Since these slabs are not major, wasted memory from these slabs would be negligible. Some architectures' page size isn't 4096 bytes and rather larger than 4096 bytes (One example is 64KB page size on PPC or IA64) so that byte sized index doesn't fit to them. In this case, we will use two bytes sized index. Below is some number for this patch. * Before * kmalloc-512 525 640 512 8 1 : tunables 54 27 0 : slabdata 80 80 0 kmalloc-256 210 210 256 15 1 : tunables 120 60 0 : slabdata 14 14 0 kmalloc-192 1016 1040 192 20 1 : tunables 120 60 0 : slabdata 52 52 0 kmalloc-96 560 620 128 31 1 : tunables 120 60 0 : slabdata 20 20 0 kmalloc-64 2148 2280 64 60 1 : tunables 120 60 0 : slabdata 38 38 0 kmalloc-128 647 682 128 31 1 : tunables 120 60 0 : slabdata 22 22 0 kmalloc-32 11360 11413 32 113 1 : tunables 120 60 0 : slabdata 101 101 0 kmem_cache 197 200 192 20 1 : tunables 120 60 0 : slabdata 10 10 0 * After * kmalloc-512 521 648 512 8 1 : tunables 54 27 0 : slabdata 81 81 0 kmalloc-256 208 208 256 16 1 : tunables 120 60 0 : slabdata 13 13 0 kmalloc-192 1029 1029 192 21 1 : tunables 120 60 0 : slabdata 49 49 0 kmalloc-96 529 589 128 31 1 : tunables 120 60 0 : slabdata 19 19 0 kmalloc-64 2142 2142 64 63 1 : tunables 120 60 0 : slabdata 34 34 0 kmalloc-128 660 682 128 31 1 : tunables 120 60 0 : slabdata 22 22 0 kmalloc-32 11716 11780 32 124 1 : tunables 120 60 0 : slabdata 95 95 0 kmem_cache 197 210 192 21 1 : tunables 120 60 0 : slabdata 10 10 0 kmem_caches consisting of objects less than or equal to 256 byte have one or more objects than before. In the case of kmalloc-32, we have 11 more objects, so 352 bytes (11 * 32) are saved and this is roughly 9% saving of memory. Of couse, this percentage decreases as the number of objects in a slab decreases. Here are the performance results on my 4 cpus machine. * Before * Performance counter stats for 'perf bench sched messaging -g 50 -l 1000' (10 runs): 229,945,138 cache-misses ( +- 0.23% ) 11.627897174 seconds time elapsed ( +- 0.14% ) * After * Performance counter stats for 'perf bench sched messaging -g 50 -l 1000' (10 runs): 218,640,472 cache-misses ( +- 0.42% ) 11.504999837 seconds time elapsed ( +- 0.21% ) cache-misses are reduced by this patchset, roughly 5%. And elapsed times are improved by 1%. Acked-by: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| * slab: restrict the number of objects in a slabJoonsoo Kim2014-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To prepare to implement byte sized index for managing the freelist of a slab, we should restrict the number of objects in a slab to be less or equal to 256, since byte only represent 256 different values. Setting the size of object to value equal or more than newly introduced SLAB_OBJ_MIN_SIZE ensures that the number of objects in a slab is less or equal to 256 for a slab with 1 page. If page size is rather larger than 4096, above assumption would be wrong. In this case, we would fall back on 2 bytes sized index. If minimum size of kmalloc is less than 16, we use it as minimum object size and give up this optimization. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| * slab: introduce helper functions to get/set free objectJoonsoo Kim2014-02-08
| | | | | | | | | | | | | | | | | | | | In the following patches, to get/set free objects from the freelist is changed so that simple casting doesn't work for it. Therefore, introduce helper functions. Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| * slab: factor out calculate nr objects in cache_estimateJoonsoo Kim2014-02-08
| | | | | | | | | | | | | | | | | | | | | | This logic is not simple to understand so that making separate function helping readability. Additionally, we can use this change in the following patch which implement for freelist to have another sized index in according to nr objects. Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
* | Merge branch 'for-linus' of ↵Linus Torvalds2014-04-12
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "The first vfs pile, with deep apologies for being very late in this window. Assorted cleanups and fixes, plus a large preparatory part of iov_iter work. There's a lot more of that, but it'll probably go into the next merge window - it *does* shape up nicely, removes a lot of boilerplate, gets rid of locking inconsistencie between aio_write and splice_write and I hope to get Kent's direct-io rewrite merged into the same queue, but some of the stuff after this point is having (mostly trivial) conflicts with the things already merged into mainline and with some I want more testing. This one passes LTP and xfstests without regressions, in addition to usual beating. BTW, readahead02 in ltp syscalls testsuite has started giving failures since "mm/readahead.c: fix readahead failure for memoryless NUMA nodes and limit readahead pages" - might be a false positive, might be a real regression..." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) missing bits of "splice: fix racy pipe->buffers uses" cifs: fix the race in cifs_writev() ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure kill generic_file_buffered_write() ocfs2_file_aio_write(): switch to generic_perform_write() ceph_aio_write(): switch to generic_perform_write() xfs_file_buffered_aio_write(): switch to generic_perform_write() export generic_perform_write(), start getting rid of generic_file_buffer_write() generic_file_direct_write(): get rid of ppos argument btrfs_file_aio_write(): get rid of ppos kill the 5th argument of generic_file_buffered_write() kill the 4th argument of __generic_file_aio_write() lustre: don't open-code kernel_recvmsg() ocfs2: don't open-code kernel_recvmsg() drbd: don't open-code kernel_recvmsg() constify blk_rq_map_user_iov() and friends lustre: switch to kernel_sendmsg() ocfs2: don't open-code kernel_sendmsg() take iov_iter stuff to mm/iov_iter.c process_vm_access: tidy up a bit ...
| * | missing bits of "splice: fix racy pipe->buffers uses"Al Viro2014-04-12
| | | | | | | | | | | | | | | | | | | | | that commit has fixed only the parts of that mess in fs/splice.c itself; there had been more in several other ->splice_read() instances... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | kill generic_file_buffered_write()Al Viro2014-04-01
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | export generic_perform_write(), start getting rid of generic_file_buffer_write()Al Viro2014-04-01
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | generic_file_direct_write(): get rid of ppos argumentAl Viro2014-04-01
| | | | | | | | | | | | | | | | | | always equal to &iocb->ki_pos. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | kill the 5th argument of generic_file_buffered_write()Al Viro2014-04-01
| | | | | | | | | | | | | | | | | | same story - it's &iocb->ki_pos in all cases Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | kill the 4th argument of __generic_file_aio_write()Al Viro2014-04-01
| | | | | | | | | | | | | | | | | | | | | It's always equal to &iocb->ki_pos, where iocb is the value of the 1st argument. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | take iov_iter stuff to mm/iov_iter.cAl Viro2014-04-01
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | process_vm_access: tidy up a bitAl Viro2014-04-01
| | | | | | | | | | | | | | | | | | saner variable names, update linuxdoc comments, etc. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | process_vm_access: don't bother with returning the amounts of bytes copiedAl Viro2014-04-01
| | | | | | | | | | | | | | | | | | we can calculate that in the caller just fine, TYVM Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | process_vm_rw_pages(): pass accurate amount of bytesAl Viro2014-04-01
| | | | | | | | | | | | | | | | | | ... makes passing the amount of pages unnecessary Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | process_vm_access: take get_user_pages/put_pages one level upAl Viro2014-04-01
| | | | | | | | | | | | | | | | | | ... and trim the fuck out of process_vm_rw_pages() argument list. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | process_vm_access: switch to copy_page_to_iter/iov_iter_copy_from_userAl Viro2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | ... rather than open-coding those. As a side benefit, we get much saner loop calling those; we can just feed entire pages, instead of the "copy would span the iovec boundary, let's do it in two loop iterations" mess. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | process_vm_access: switch to iov_iterAl Viro2014-04-01
| | | | | | | | | | | | | | | | | | | | | instead of keeping its pieces in separate variables and passing pointers to all of them... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | untangling process_vm_..., part 4Al Viro2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | instead of passing vector size (by value) and index (by reference), pass the number of elements remaining. That's all we care about in these functions by that point. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | untangling process_vm_..., part 3Al Viro2014-04-01
| | | | | | | | | | | | | | | | | | | | | lift iov one more level out - from process_vm_rw_single_vec to process_vm_rw_core(). Same story as with the previous commit. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | untangling process_vm_..., part 2Al Viro2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | move iov to caller's stack frame; the value we assign to it on the next call of process_vm_rw_pages() is equal to the value it had when the last time we were leaving process_vm_rw_pages(). drop lvec argument of process_vm_rw_pages() - it's not used anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | untangling process_vm_..., part 1Al Viro2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | we want to massage it to use of iov_iter. This one is an equivalent transformation - just introduce a local variable mirroring lvec + *lvec_current. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | introduce copy_page_to_iter, kill loop over iovec in generic_file_aio_read()Al Viro2014-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | generic_file_aio_read() was looping over the target iovec, with loop over (source) pages nested inside that. Just set an iov_iter up and pass *that* to do_generic_file_aio_read(). With copy_page_to_iter() doing all work of mapping and copying a page to iovec and advancing iov_iter. Switch shmem_file_aio_read() to the same and kill file_read_actor(), while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | do_shmem_file_read(): call file_read_actor() directlyAl Viro2014-04-01
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | callers of iov_copy_from_user_atomic() don't need pagecache_disable()Al Viro2014-04-01
| | | | | | | | | | | | | | | | | | ... it does that itself (via kmap_atomic()) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | switch ->is_partially_uptodate() to saner argumentsAl Viro2014-04-01
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | Merge git://git.infradead.org/users/eparis/auditLinus Torvalds2014-04-12
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull audit updates from Eric Paris. * git://git.infradead.org/users/eparis/audit: (28 commits) AUDIT: make audit_is_compat depend on CONFIG_AUDIT_COMPAT_GENERIC audit: renumber AUDIT_FEATURE_CHANGE into the 1300 range audit: do not cast audit_rule_data pointers pointlesly AUDIT: Allow login in non-init namespaces audit: define audit_is_compat in kernel internal header kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c sched: declare pid_alive as inline audit: use uapi/linux/audit.h for AUDIT_ARCH declarations syscall_get_arch: remove useless function arguments audit: remove stray newline from audit_log_execve_info() audit_panic() call audit: remove stray newlines from audit_log_lost messages audit: include subject in login records audit: remove superfluous new- prefix in AUDIT_LOGIN messages audit: allow user processes to log from another PID namespace audit: anchor all pid references in the initial pid namespace audit: convert PPIDs to the inital PID namespace. pid: get pid_t ppid of task in init_pid_ns audit: rename the misleading audit_get_context() to audit_take_context() audit: Add generic compat syscall support audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL ...
| * | | mm: Create utility function for accessing a tasks commandline valueWilliam Roberts2014-03-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | introduce get_cmdline() for retreiving the value of a processes proc/self/cmdline value. Acked-by: David Rientjes <rientjes@google.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: William Roberts <wroberts@tresys.com> Signed-off-by: Eric Paris <eparis@redhat.com>
* | | | mm: vmscan: do not swap anon pages just because free+file is lowJohannes Weiner2014-04-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Page reclaim force-scans / swaps anonymous pages when file cache drops below the high watermark of a zone in order to prevent what little cache remains from thrashing. However, on bigger machines the high watermark value can be quite large and when the workload is dominated by a static anonymous/shmem set, the file set might just be a small window of used-once cache. In such situations, the VM starts swapping heavily when instead it should be recycling the no longer used cache. This is a longer-standing problem, but it's more likely to trigger after commit 81c0a2bb515f ("mm: page_alloc: fair zone allocator policy") because file pages can no longer accumulate in a single zone and are dispersed into smaller fractions among the available zones. To resolve this, do not force scan anon when file pages are low but instead rely on the scan/rotation ratios to make the right prediction. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Rafael Aquini <aquini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: <stable@kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge branch 'akpm' (incoming from Andrew)Linus Torvalds2014-04-07
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge second patch-bomb from Andrew Morton: - the rest of MM - zram updates - zswap updates - exit - procfs - exec - wait - crash dump - lib/idr - rapidio - adfs, affs, bfs, ufs - cris - Kconfig things - initramfs - small amount of IPC material - percpu enhancements - early ioremap support - various other misc things * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (156 commits) MAINTAINERS: update Intel C600 SAS driver maintainers fs/ufs: remove unused ufs_super_block_third pointer fs/ufs: remove unused ufs_super_block_second pointer fs/ufs: remove unused ufs_super_block_first pointer fs/ufs/super.c: add __init to init_inodecache() doc/kernel-parameters.txt: add early_ioremap_debug arm64: add early_ioremap support arm64: initialize pgprot info earlier in boot x86: use generic early_ioremap mm: create generic early_ioremap() support x86/mm: sparse warning fix for early_memremap lglock: map to spinlock when !CONFIG_SMP percpu: add preemption checks to __this_cpu ops vmstat: use raw_cpu_ops to avoid false positives on preemption checks slub: use raw_cpu_inc for incrementing statistics net: replace __this_cpu_inc in route.c with raw_cpu_inc modules: use raw_cpu_write for initialization of per cpu refcount. mm: use raw_cpu ops for determining current NUMA node percpu: add raw_cpu_ops slub: fix leak of 'name' in sysfs_slab_add ...
| * | | | mm: create generic early_ioremap() supportMark Salter2014-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch creates a generic implementation of early_ioremap() support based on the existing x86 implementation. early_ioremp() is useful for early boot code which needs to temporarily map I/O or memory regions before normal mapping functions such as ioremap() are available. Some architectures have optional MMU. In the no-MMU case, the remap functions simply return the passed in physical address and the unmap functions do nothing. Signed-off-by: Mark Salter <msalter@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Borislav Petkov <borislav.petkov@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | slub: use raw_cpu_inc for incrementing statisticsChristoph Lameter2014-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Statistics are not critical to the operation of the allocation but should also not cause too much overhead. When __this_cpu_inc is altered to check if preemption is disabled this triggers. Use raw_cpu_inc to avoid the checks. Using this_cpu_ops may cause interrupt disable/enable sequences on various arches which may significantly impact allocator performance. [akpm@linux-foundation.org: add comment] Signed-off-by: Christoph Lameter <cl@linux.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | slub: fix leak of 'name' in sysfs_slab_addDave Jones2014-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The failure paths of sysfs_slab_add don't release the allocation of 'name' made by create_unique_id() a few lines above the context of the diff below. Create a common exit path to make it more obvious what needs freeing. [vdavydov@parallels.com: free the name only if !unmergeable] Signed-off-by: Dave Jones <davej@fedoraproject.org> Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | slub: rework sysfs layout for memcg cachesVladimir Davydov2014-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, we try to arrange sysfs entries for memcg caches in the same manner as for global caches. Apart from turning /sys/kernel/slab into a mess when there are a lot of kmem-active memcgs created, it actually does not work properly - we won't create more than one link to a memcg cache in case its parent is merged with another cache. For instance, if A is a root cache merged with another root cache B, we will have the following sysfs setup: X A -> X B -> X where X is some unique id (see create_unique_id()). Now if memcgs M and N start to allocate from cache A (or B, which is the same), we will get: X X:M X:N A -> X B -> X A:M -> X:M A:N -> X:N Since B is an alias for A, we won't get entries B:M and B:N, which is confusing. It is more logical to have entries for memcg caches under the corresponding root cache's sysfs directory. This would allow us to keep sysfs layout clean, and avoid such inconsistencies like one described above. This patch does the trick. It creates a "cgroup" kset in each root cache kobject to keep its children caches there. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Glauber Costa <glommer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | slub: adjust memcg caches when creating cache aliasVladimir Davydov2014-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Otherwise, kzalloc() called from a memcg won't clear the whole object. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Glauber Costa <glommer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | memcg, slab: do not destroy children caches if parent has aliasesVladimir Davydov2014-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we destroy children caches at the very beginning of kmem_cache_destroy(). This is wrong, because the root cache will not necessarily be destroyed in the end - if it has aliases (refcount > 0), kmem_cache_destroy() will simply decrement its refcount and return. In this case, at best we will get a bunch of warnings in dmesg, like this one: kmem_cache_destroy kmalloc-32:0: Slab cache still has objects CPU: 1 PID: 7139 Comm: modprobe Tainted: G B W 3.13.0+ #117 Call Trace: dump_stack+0x49/0x5b kmem_cache_destroy+0xdf/0xf0 kmem_cache_destroy_memcg_children+0x97/0xc0 kmem_cache_destroy+0xf/0xf0 xfs_mru_cache_uninit+0x21/0x30 [xfs] exit_xfs_fs+0x2e/0xc44 [xfs] SyS_delete_module+0x198/0x1f0 system_call_fastpath+0x16/0x1b At worst - if kmem_cache_destroy() will race with an allocation from a memcg cache - the kernel will panic. This patch fixes this by moving children caches destruction after the check if the cache has aliases. Plus, it forbids destroying a root cache if it still has children caches, because each children cache keeps a reference to its parent. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Glauber Costa <glommer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | memcg, slab: unregister cache from memcg before starting to destroy itVladimir Davydov2014-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, memcg_unregister_cache(), which deletes the cache being destroyed from the memcg_slab_caches list, is called after __kmem_cache_shutdown() (see kmem_cache_destroy()), which starts to destroy the cache. As a result, one can access a partially destroyed cache while traversing a memcg_slab_caches list, which can have deadly consequences (for instance, cache_show() called for each cache on a memcg_slab_caches list from mem_cgroup_slabinfo_read() will dereference pointers to already freed data). To fix this, let's move memcg_unregister_cache() before the cache destruction process beginning, issuing memcg_register_cache() on failure. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Glauber Costa <glommer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | memcg, slab: separate memcg vs root cache creation pathsVladimir Davydov2014-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Memcg-awareness turned kmem_cache_create() into a dirty interweaving of memcg-only and except-for-memcg calls. To clean this up, let's move the code responsible for memcg cache creation to a separate function. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Glauber Costa <glommer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | memcg, slab: cleanup memcg cache creationVladimir Davydov2014-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch cleans up the memcg cache creation path as follows: - Move memcg cache name creation to a separate function to be called from kmem_cache_create_memcg(). This allows us to get rid of the mutex protecting the temporary buffer used for the name formatting, because the whole cache creation path is protected by the slab_mutex. - Get rid of memcg_create_kmem_cache(). This function serves as a proxy to kmem_cache_create_memcg(). After separating the cache name creation path, it would be reduced to a function call, so let's inline it. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Glauber Costa <glommer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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