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* mm: Disable optimization for function shrink_page_list()Wolfgang Wiedmeyer2019-07-241-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | GCC version 5.4.1+svn241155-1 in Debian Stretch has a bug that breaks the build. The error is attached. TODO: Gigure out the actual bug or revert patch if a newer GCC is available in Stretch. /home/wolfi/6.0-romsrc/kernel/samsung/smdk4412/mm/vmscan.c: In function 'shrink_page_list': /home/wolfi/6.0-romsrc/kernel/samsung/smdk4412/mm/vmscan.c:1019:1: error: insn does not satisfy its constraints: } ^ (insn 1111 1814 1112 116 (parallel [ (set (reg/v:SI 3 r3 [orig:111 nr_dirty ] [111]) (and:SI (ne:SI (reg/v:SI 3 r3 [orig:111 nr_dirty ] [111]) (const_int 0 [0])) (eq:SI (reg/v:SI 3 r3 [orig:111 nr_dirty ] [111]) (reg/v:SI 2 r2 [orig:112 nr_congested ] [112])))) (clobber (reg:CC 100 cc)) ]) /home/wolfi/6.0-romsrc/kernel/samsung/smdk4412/mm/vmscan.c:1011 256 {*and_scc_scc_nodom} (nil)) /home/wolfi/6.0-romsrc/kernel/samsung/smdk4412/mm/vmscan.c:1019:1: internal compiler error: in extract_constrain_insn, at recog.c:2246 /home/wolfi/6.0-romsrc/kernel/samsung/smdk4412/mm/vmscan.c:1019:1: internal compiler error: Segmentation fault arm-none-eabi-gcc: internal compiler error: Segmentation fault (program cc1) Signed-off-by: Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de>
* mm: remove gup_flags FOLL_WRITE games from __get_user_pages()Linus Torvalds2016-10-291-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is an ancient bug that was actually attempted to be fixed once (badly) by me eleven years ago in commit 4ceb5db9757a ("Fix get_user_pages() race for write access") but that was then undone due to problems on s390 by commit f33ea7f404e5 ("fix get_user_pages bug"). In the meantime, the s390 situation has long been fixed, and we can now fix it by checking the pte_dirty() bit properly (and do it better). The s390 dirty bit was implemented in abf09bed3cce ("s390/mm: implement software dirty bits") which made it into v3.9. Earlier kernels will have to look at the page state itself. Also, the VM has become more scalable, and what used a purely theoretical race back then has become easier to trigger. To fix it, we introduce a new internal FOLL_COW flag to mark the "yes, we already did a COW" rather than play racy games with FOLL_WRITE that is very fundamental, and then use the pte dirty flag to validate that the FOLL_COW flag is still valid. Change-Id: Id9bec3722797dff7d0ff0d9f6097c4229e31fd62 Reported-and-tested-by: Phil "not Paul" Oester <kernel@linuxace.com> Acked-by: Hugh Dickins <hughd@google.com> Reviewed-by: Michal Hocko <mhocko@suse.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Nick Piggin <npiggin@gmail.com> Cc: Greg Thelen <gthelen@google.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [wt: s/gup.c/memory.c; s/follow_page_pte/follow_page_mask; s/faultin_page/__get_user_page] Signed-off-by: Willy Tarreau <w@1wt.eu>
* ashmem: Move to drivers/staging/android; fix odd merges.Kyle Repinski2016-10-292-755/+0
| | | | | Change-Id: Ie8d4dea92c9bc9c5efe69886db05f93b3487f3a4 Signed-off-by: Kyle Repinski <repinski23@gmail.com>
* FROMLIST: mm: mmap: Add new /proc tunable for mmap_base ASLR.dcashman2016-10-291-0/+12
| | | | | | | | | | | | | | | | | (cherry picked from commit https://lkml.org/lkml/2015/12/21/337) ASLR only uses as few as 8 bits to generate the random offset for the mmap base address on 32 bit architectures. This value was chosen to prevent a poorly chosen value from dividing the address space in such a way as to prevent large allocations. This may not be an issue on all platforms. Allow the specification of a minimum number of bits so that platforms desiring greater ASLR protection may determine where to place the trade-off. Bug: 24047224 Signed-off-by: Daniel Cashman <dcashman@android.com> Signed-off-by: Daniel Cashman <dcashman@google.com> Change-Id: Ic74424e07710cd9ccb4a02871a829d14ef0cc4bc
* Write dirty pages in migration only in SYNC mode.Luden2016-05-011-4/+6
| | | | | | I'm not super-sure about this whole idea of dirty pages writing, but so far haven't seen any problems attributable to it - so leaving it in there, but restricting to SYNC migrations only.
* Added buffers flushing for dirty pages.Luden2016-05-011-0/+21
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* ksm_migrate_page() changes from the mainline.Luden2016-05-011-0/+8
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* Extra CMA debugging code.Luden2016-05-014-21/+187
| | | | | | Added extra CMA debugging logging into FS, compaction, isolation and migration code. This makes it easier to see which parts of the kernel are responsible for the most migration failures.
* Retry CMA allocations.Luden2016-05-012-61/+103
| | | | | | | | | | | | | | | | | | It looks like Linux pages migration code was never designed to be deterministic or synchronous, there are multiple race conditions between different parts of the code that make CMA allocation in one step very likely to fail, especially for large memory ranges that we need for Ducati. Therefore, changing the allocation code to perform multiple allocation attempts. To further increase the chances of the allocation to succeed and to make things faster, the results of the previous allocation attempts are kept - that is, all pages that are already isolated stay isolated, so that retries are only for those pages that failed isolation or migration in previous steps. Additionally, there's a small delay between the steps so that the chances of the other code to free the pages we need are higher.
* CMA fixes for kernel 3.0Luden2016-05-013-6/+37
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* cma: fix migration modeMinchan Kim2016-04-031-1/+1
| | | | | | | | | | __alloc_contig_migrate_range calls migrate_pages with wrong argument for migrate_mode. Fix it. Cc: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
* mm: trigger page reclaim in alloc_contig_range() to stabilise watermarksMarek Szyprowski2016-04-031-0/+61
| | | | | | | | | | | | | | | | | | | | alloc_contig_range() performs memory allocation so it also should keep track on keeping the correct level of memory watermarks. This commit adds a call to *_slowpath style reclaim to grab enough pages to make sure that the final collection of contiguous pages from freelists will not starve the system. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> CC: Michal Nazarewicz <mina86@mina86.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com> Conflicts: mm/page_alloc.c
* mm: extract reclaim code from __alloc_pages_direct_reclaim()Marek Szyprowski2016-04-031-9/+21
| | | | | | | | | | | | | | | | This patch extracts common reclaim code from __alloc_pages_direct_reclaim() function to separate function: __perform_reclaim() which can be later used by alloc_contig_range(). Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
* mm: Serialize access to min_free_kbytesMel Gorman2016-04-031-8/+15
| | | | | | | | | | | | | There is a race between the min_free_kbytes sysctl, memory hotplug and transparent hugepage support enablement. Memory hotplug uses a zonelists_mutex to avoid a race when building zonelists. Reuse it to serialise watermark updates. [a.p.zijlstra@chello.nl: Older patch fixed the race with spinlock] Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Barry Song <Baohua.Song@csr.com>
* mm: mmzone: MIGRATE_CMA migration type addedMichal Nazarewicz2016-04-034-20/+72
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The MIGRATE_CMA migration type has two main characteristics: (i) only movable pages can be allocated from MIGRATE_CMA pageblocks and (ii) page allocator will never change migration type of MIGRATE_CMA pageblocks. This guarantees (to some degree) that page in a MIGRATE_CMA page block can always be migrated somewhere else (unless there's no memory left in the system). It is designed to be used for allocating big chunks (eg. 10MiB) of physically contiguous memory. Once driver requests contiguous memory, pages from MIGRATE_CMA pageblocks may be migrated away to create a contiguous block. To minimise number of migrations, MIGRATE_CMA migration type is the last type tried when page allocator falls back to other migration types when requested. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
* mm: page_alloc: change fallbacks array handlingMichal Nazarewicz2016-04-031-4/+5
| | | | | | | | | | | | | | | | | | This commit adds a row for MIGRATE_ISOLATE type to the fallbacks array which was missing from it. It also, changes the array traversal logic a little making MIGRATE_RESERVE an end marker. The letter change, removes the implicit MIGRATE_UNMOVABLE from the end of each row which was read by __rmqueue_fallback() function. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
* mm: page_alloc: remove trailing whitespaceMichal Nazarewicz2016-04-031-7/+7
| | | | | | Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Mel Gorman <mel@csn.ul.ie>
* mm: page_isolation: MIGRATE_CMA isolation functions addedMichal Nazarewicz2016-04-034-17/+23
| | | | | | | | | | | | | | | | This commit changes various functions that change pages and pageblocks migrate type between MIGRATE_ISOLATE and MIGRATE_MOVABLE in such a way as to allow to work with MIGRATE_CMA migrate type. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
* mm: page_alloc: introduce alloc_contig_range()Michal Nazarewicz2016-04-031-0/+188
| | | | | | | | | | | | | | | | | | | | | | This commit adds the alloc_contig_range() function which tries to allocate given range of pages. It tries to migrate all already allocated pages that fall in the range thus freeing them. Once all pages in the range are freed they are removed from the buddy system thus allocated for the caller to use. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com> Conflicts: include/linux/gfp.h mm/page_alloc.c
* mm: compaction: export some of the functionsMichal Nazarewicz2016-04-033-173/+191
| | | | | | | | | | | | | | | | | | | | | | | | This commit exports some of the functions from compaction.c file outside of it adding their declaration into internal.h header file so that other mm related code can use them. This forced compaction.c to always be compiled (as opposed to being compiled only if CONFIG_COMPACTION is defined) but as to avoid introducing code that user did not ask for, part of the compaction.c is now wrapped in on #ifdef. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com> Conflicts: mm/compaction.c
* mm: compaction: introduce isolate_freepages_range()Michal Nazarewicz2016-04-031-18/+93
| | | | | | | | | | | | | | | | | | This commit introduces isolate_freepages_range() function which generalises isolate_freepages_block() so that it can be used on arbitrary PFN ranges. isolate_freepages_block() is left with only minor changes. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
* mm: compaction: introduce map_pages()Michal Nazarewicz2016-04-031-4/+11
| | | | | | | | | | | | | This commit creates a map_pages() function which map pages freed using split_free_pages(). This merely moves some code from isolate_freepages() so that it can be reused in other places. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
* mm: compaction: introduce isolate_migratepages_range()Michal Nazarewicz2016-04-031-21/+54
| | | | | | | | | | | | | | | | | | | This commit introduces isolate_migratepages_range() function which extracts functionality from isolate_migratepages() so that it can be used on arbitrary PFN ranges. isolate_migratepages() function is implemented as a simple wrapper around isolate_migratepages_range(). Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
* fs: introduce inode operation ->update_timeJosef Bacik2016-04-032-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | Btrfs has to make sure we have space to allocate new blocks in order to modify the inode, so updating time can fail. We've gotten around this by having our own file_update_time but this is kind of a pain, and Christoph has indicated he would like to make xfs do something different with atime updates. So introduce ->update_time, where we will deal with i_version an a/m/c time updates and indicate which changes need to be made. The normal version just does what it has always done, updates the time and marks the inode dirty, and then filesystems can choose to do something different. I've gone through all of the users of file_update_time and made them check for errors with the exception of the fault code since it's complicated and I wasn't quite sure what to do there, also Jan is going to be pushing the file time updates into page_mkwrite for those who have it so that should satisfy btrfs and make it not a big deal to check the file_update_time() return code in the generic fault path. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> (cherry picked from commit c3b2da314834499f34cba94f7053e55f6d6f92d8) Conflicts: fs/inode.c
* mm: add a field to store names for private anonymous memoryColin Cross2016-04-035-23/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Userspace processes often have multiple allocators that each do anonymous mmaps to get memory. When examining memory usage of individual processes or systems as a whole, it is useful to be able to break down the various heaps that were allocated by each layer and examine their size, RSS, and physical memory usage. This patch adds a user pointer to the shared union in vm_area_struct that points to a null terminated string inside the user process containing a name for the vma. vmas that point to the same address will be merged, but vmas that point to equivalent strings at different addresses will not be merged. Userspace can set the name for a region of memory by calling prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, start, len, (unsigned long)name); Setting the name to NULL clears it. The names of named anonymous vmas are shown in /proc/pid/maps as [anon:<name>] and in /proc/pid/smaps in a new "Name" field that is only present for named vmas. If the userspace pointer is no longer valid all or part of the name will be replaced with "<fault>". The idea to store a userspace pointer to reduce the complexity within mm (at the expense of the complexity of reading /proc/pid/mem) came from Dave Hansen. This results in no runtime overhead in the mm subsystem other than comparing the anon_name pointers when considering vma merging. The pointer is stored in a union with fieds that are only used on file-backed mappings, so it does not increase memory usage. Change-Id: I6ed36e1bcac7a29132fde1667ac0f62dcda69e44
* procfs: mark thread stack correctly in proc/<pid>/mapsSiddhesh Poyarekar2016-03-111-0/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Stack for a new thread is mapped by userspace code and passed via sys_clone. This memory is currently seen as anonymous in /proc/<pid>/maps, which makes it difficult to ascertain which mappings are being used for thread stacks. This patch uses the individual task stack pointers to determine which vmas are actually thread stacks. For a multithreaded program like the following: #include <pthread.h> void *thread_main(void *foo) { while(1); } int main() { pthread_t t; pthread_create(&t, NULL, thread_main, NULL); pthread_join(t, NULL); } proc/PID/maps looks like the following: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Here, one could guess that 7f8a44492000-7f8a44c92000 is a stack since the earlier vma that has no permissions (7f8a44e3d000-7f8a4503d000) but that is not always a reliable way to find out which vma is a thread stack. Also, /proc/PID/maps and /proc/PID/task/TID/maps has the same content. With this patch in place, /proc/PID/task/TID/maps are treated as 'maps as the task would see it' and hence, only the vma that that task uses as stack is marked as [stack]. All other 'stack' vmas are marked as anonymous memory. /proc/PID/maps acts as a thread group level view, where all thread stack vmas are marked as [stack:TID] where TID is the process ID of the task that uses that vma as stack, while the process stack is marked as [stack]. So /proc/PID/maps will look like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Thus marking all vmas that are used as stacks by the threads in the thread group along with the process stack. The task level maps will however like this: 00400000-00401000 r-xp 00000000 fd:0a 3671804 /home/siddhesh/a.out 00600000-00601000 rw-p 00000000 fd:0a 3671804 /home/siddhesh/a.out 019ef000-01a10000 rw-p 00000000 00:00 0 [heap] 7f8a44491000-7f8a44492000 ---p 00000000 00:00 0 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] 7f8a44c92000-7f8a44e3d000 r-xp 00000000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a44e3d000-7f8a4503d000 ---p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a4503d000-7f8a45041000 r--p 001ab000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45041000-7f8a45043000 rw-p 001af000 fd:00 2097482 /lib64/libc-2.14.90.so 7f8a45043000-7f8a45048000 rw-p 00000000 00:00 0 7f8a45048000-7f8a4505f000 r-xp 00000000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4505f000-7f8a4525e000 ---p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525e000-7f8a4525f000 r--p 00016000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a4525f000-7f8a45260000 rw-p 00017000 fd:00 2099938 /lib64/libpthread-2.14.90.so 7f8a45260000-7f8a45264000 rw-p 00000000 00:00 0 7f8a45264000-7f8a45286000 r-xp 00000000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45457000-7f8a4545a000 rw-p 00000000 00:00 0 7f8a45484000-7f8a45485000 rw-p 00000000 00:00 0 7f8a45485000-7f8a45486000 r--p 00021000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45486000-7f8a45487000 rw-p 00022000 fd:00 2097348 /lib64/ld-2.14.90.so 7f8a45487000-7f8a45488000 rw-p 00000000 00:00 0 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 7fff627ff000-7fff62800000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] where only the vma that is being used as a stack by *that* task is marked as [stack]. Analogous changes have been made to /proc/PID/smaps, /proc/PID/numa_maps, /proc/PID/task/TID/smaps and /proc/PID/task/TID/numa_maps. Relevant snippets from smaps and numa_maps: [siddhesh@localhost ~ ]$ pgrep a.out 1441 [siddhesh@localhost ~ ]$ cat /proc/1441/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack:1442] 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/smaps | grep "\[stack" 7f8a44492000-7f8a44c92000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/smaps | grep "\[stack" 7fff6273b000-7fff6275c000 rw-p 00000000 00:00 0 [stack] [siddhesh@localhost ~ ]$ cat /proc/1441/numa_maps | grep "stack" 7f8a44492000 default stack:1442 anon=2 dirty=2 N0=2 7fff6273a000 default stack anon=3 dirty=3 N0=3 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1442/numa_maps | grep "stack" 7f8a44492000 default stack anon=2 dirty=2 N0=2 [siddhesh@localhost ~ ]$ cat /proc/1441/task/1441/numa_maps | grep "stack" 7fff6273a000 default stack anon=3 dirty=3 N0=3 [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix build] Signed-off-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jamie Lokier <jamie@shareable.org> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm:ashmem: avoid ashmem deadlockYuanyuan Zhong2016-01-081-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is propagation of change done in (CR). When system memory is low, allocating memory while holding the ashmem_mutex may try to directly reclaim memory. Then ashmem_shrink() is called in same thread. It will deadlock at acquiring ashmem_mutex. We end up with stack like this: Task name: app_process pid: 16442 cpu: 0 state: 0x2 exit_state: 0x0 stack base: 0xc876c000 Stack: [<c084ce20>] __schedule+0x664 [<c084dea4>] __mutex_lock_slowpath+0x220 [<c084ea48>] mutex_lock+0x20 [<c021f104>] ashmem_shrink+0x44 [<c01fe3a0>] shrink_slab+0x228 [<c01ff38c>] try_to_free_pages+0x3c8 [<c01f483c>] __alloc_pages_nodemask+0x4a8 [<c02236fc>] new_slab+0x70 [<c0224928>] __slab_alloc.clone.1+0x248 [<c0224bb4>] kmem_cache_alloc+0xa0 [<c020174c>] shmem_alloc_inode+0x14 [<c0243670>] alloc_inode+0x1c [<c02439e4>] new_inode_pseudo+0x8 [<c0243a24>] new_inode+0x8 [<c0200a0c>] shmem_get_inode+0x2c [<c0200c80>] shmem_file_setup+0x10c [<c021f030>] ashmem_mmap+0x8c [<c0212618>] mmap_region+0x2b8 [<c0212bc4>] sys_mmap_pgoff+0x8c [<c0106000>] ret_fast_syscall+0x0 This change lets ashmem_shrink() return failure if ashmem_mutex is not available. Memory will be reclaimed from others. Change-Id: I3b2193b6e4fca4eeafd558b919ba8a76894a33a1 Signed-off-by: Yuanyuan Zhong <a6510c@motorola.com> Reviewed-on: http://gerrit.pcs.mot.com/498700 Tested-by: Jira Key <JIRAKEY@motorola.com> Reviewed-by: Check Patch <CHEKPACH@motorola.com> Reviewed-by: Klocwork kwcheck <klocwork-kwcheck@sourceforge.mot.com> Reviewed-by: Jeffrey Carlyle <jeff.carlyle@motorola.com> Reviewed-on: http://gerrit.pcs.mot.com/520376 Tested-by: Jira Key <jirakey@motorola.com> Submit-Approved: Jira Key <jirakey@motorola.com>
* mm: page_alloc: retry direct compactionYi-wei Zhao2016-01-082-2/+29
| | | | | | | | | | | | | | | | | | | | | When system load is heavy, memory commpaction may encounter transient failure; add retry mechanism. And add the following statistic variable "compact_retry_success" in /proc/vmstat to see how many compaction success due to the retry. And __zone_watermark_ok() will easily return false when system is busy, which will make compaction failure as well. Amend some to save margin cases. This patch is ported from the patch: * (CR) mem compaction enhancement Reviewed-on: http://gerrit.pcs.mot.com/494962 Change-Id: I5ad08364678c7e68993f66e0c0d43d97712a99b6 Signed-off-by: Yi-wei Zhao <gbjc64@motorola.com> Reviewed-on: http://gerrit.pcs.mot.com/507230 Tested-by: Jira Key <JIRAKEY@motorola.com> Reviewed-by: Jason Hrycay <jason.hrycay@motorola.com>
* radix_tree: exceptional entries and indicesHugh Dickins2016-01-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A patchset to extend tmpfs to MAX_LFS_FILESIZE by abandoning its peculiar swap vector, instead keeping a file's swap entries in the same radix tree as its struct page pointers: thus saving memory, and simplifying its code and locking. This patch: The radix_tree is used by several subsystems for different purposes. A major use is to store the struct page pointers of a file's pagecache for memory management. But what if mm wanted to store something other than page pointers there too? The low bit of a radix_tree entry is already used to denote an indirect pointer, for internal use, and the unlikely radix_tree_deref_retry() case. Define the next bit as denoting an exceptional entry, and supply inline functions radix_tree_exception() to return non-0 in either unlikely case, and radix_tree_exceptional_entry() to return non-0 in the second case. If a subsystem already uses radix_tree with that bit set, no problem: it does not affect internal workings at all, but is defined for the convenience of those storing well-aligned pointers in the radix_tree. The radix_tree_gang_lookups have an implicit assumption that the caller can deduce the offset of each entry returned e.g. by the page->index of a struct page. But that may not be feasible for some kinds of item to be stored there. radix_tree_gang_lookup_slot() allow for an optional indices argument, output array in which to return those offsets. The same could be added to other radix_tree_gang_lookups, but for now keep it to the only one for which we need it. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ksm: check and skip page, if it is already scannedPradeep Sawlani2016-01-082-2/+41
| | | | | | | | | | | | | | | | | | | | | | From: Pradeep Sawlani <sawlani@amazon.com> On system like Android where most of the process are forked from parent w/o execve, KSM can scan same page multiple times in one scan cycle. There is no advantage in scanning same page multiple times for merging. During testing with Android, it was observed around 60% pages are skipped for each scan cycle. Change-Id: I0cf01802f0b4d61fcab92558beb9e1c660dc9a77 Link: http://lkml.kernel.org/r/CAMrOTPgBtANS_ryRjan0-dTL97U7eRvtf3dCsss=Kn+Uk89fuA@mail.gmail.com Signed-off-by: Pradeep Sawlani <sawlani@amazon.com> Signed-off-by: Paul Reioux <reioux@gmail.com> Conflicts: include/linux/page-flags.h Conflicts: include/linux/page-flags.h
* cgroup: introduce cgroup_taskset and use it in subsys->can_attach(), ↵Tejun Heo2016-01-081-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | cancel_attach() and attach() Currently, there's no way to pass multiple tasks to cgroup_subsys methods necessitating the need for separate per-process and per-task methods. This patch introduces cgroup_taskset which can be used to pass multiple tasks and their associated cgroups to cgroup_subsys methods. Three methods - can_attach(), cancel_attach() and attach() - are converted to use cgroup_taskset. This unifies passed parameters so that all methods have access to all information. Conversions in this patchset are identical and don't introduce any behavior change. -v2: documentation updated as per Paul Menage's suggestion. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Paul Menage <paul@paulmenage.org> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: James Morris <jmorris@namei.org>
* mm: pass readahead info down to the i/o schedulerLee Susman2016-01-082-0/+4
| | | | | | | | | | | | | | | | | | | | | | Some i/o schedulers (i.e. row-iosched, cfq-iosched) deploy an idling algorithm in order to be better synced with the readahead algorithm. Idling is a prediction algorithm for incoming read requests. In this patch we mark pages which are part of a readahead window, by setting a newly introduced flag. With this flag, the i/o scheduler can identify a request which is associated with a readahead page. This enables the i/o scheduler's idling mechanism to be en-sync with the readahead mechanism and, in turn, can increase read throughput. Change-Id: I0654f23315b6d19d71bcc9cc029c6b281a44b196 Signed-off-by: Lee Susman <lsusman@codeaurora.org> Signed-off-by: Paul Reioux <reioux@gmail.com> Conflicts: include/linux/page-flags.h Conflicts: include/linux/page-flags.h
* make default readahead size a kernel parameterWu Fengguang2016-01-081-0/+26
| | | | | | | | | | | | | | | | From: Nikanth Karthikesan <knikanth@suse.de> Add new kernel parameter "readahead", which would be used instead of the value of VM_MAX_READAHEAD. If the parameter is not specified, the default of 128kb would be used. Change-Id: I58540d4c3570d23befb9b9f1e27998e832eae88b CC: Ankit Jain <radical@gmail.com> CC: Dave Chinner <david@fromorbit.com> CC: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: D. Andrei Măceș <dmaces@nd.edu>
* mm/vmscan: Add #ifdef around "WasActive page flag"Paul Reioux2016-01-051-0/+6
| | | | also fix a merge error @ putback_lru_page
* mm: implement WasActive page flag (for improving cleancache)Dan Magenheimer2016-01-051-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (Feedback welcome if there is a different/better way to do this without using a page flag!) Since about 2.6.27, the page replacement algorithm maintains an "active" bit to help decide which pages are most eligible to reclaim, see http://linux-mm.org/PageReplacementDesign This "active' information is also useful to cleancache but is lost by the time that cleancache has the opportunity to preserve the pageful of data. This patch adds a new page flag "WasActive" to retain the state. The flag may possibly be useful elsewhere. It is up to each cleancache backend to utilize the bit as it desires. The matching patch for zcache is included here for clarification/discussion purposes, though it will need to go through GregKH and the staging tree. The patch resolves issues reported with cleancache which occur especially during streaming workloads on older processors, see https://lkml.org/lkml/2011/8/17/351 Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> Conflicts: include/linux/page-flags.h Change-Id: I0fcb2302a7b9c5e66db005229f679baee90f262f Conflicts: include/linux/page-flags.h
* mm: remove compressed copy from zram in-memoryMinchan Kim2016-01-051-2/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Swap subsystem does lazy swap slot free with expecting the page would be swapped out again so we can avoid unnecessary write. But the problem in in-memory swap(ex, zram) is that it consumes memory space until vm_swap_full(ie, used half of all of swap device) condition meet. It could be bad if we use multiple swap device, small in-memory swap and big storage swap or in-memory swap alone. This patch makes swap subsystem free swap slot as soon as swap-read is completed and make the swapcache page dirty so the page should be written out the swap device to reclaim it. It means we never lose it. I tested this patch with kernel compile workload. 1. before compile time : 9882.42 zram max wasted space by fragmentation: 13471881 byte memory space consumed by zram: 174227456 byte the number of slot free notify: 206684 2. after compile time : 9653.90 zram max wasted space by fragmentation: 11805932 byte memory space consumed by zram: 154001408 byte the number of slot free notify: 426972 [akpm@linux-foundation.org: tweak comment text] [artem.savkov@gmail.com: fix BUG due to non-swapcache pages in end_swap_bio_read()] [akpm@linux-foundation.org: invert unlikely() test, augment comment, 80-col cleanup] Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Artem Savkov <artem.savkov@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Konrad Rzeszutek Wilk <konrad@darnok.org> Cc: Shaohua Li <shli@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Change-Id: I8f11fb7f0391954435002e7f290352f311c907d4 Signed-off-by: Paul Reioux <reioux@gmail.com> Conflicts: mm/page_io.c
* mm: Need page_swap_info() helper method from upstreamD. Andrei Măceș2016-01-051-0/+7
| | | | | | | | Stolen from commit f981c5950fa85916ba49bea5d9a7a5078f47e569: "mm: methods for teaching filesystems about PG_swapcache pages" Change-Id: I6673913f9c825d3a6de88a652e99bcaf04eb1dd6
* mm: swap: don't delay swap free for fast swap devicesVinayak Menon2016-01-053-6/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are couple of issues with swapcache usage when ZRAM is used as swap device. 1) Kernel does a swap readahead which can be around 6 to 8 pages depending on total ram, which is not required for zram since accesses are fast. 2) Kernel delays the freeing up of swapcache expecting a later hit, which again is useless in the case of zram. 3) This is not related to swapcache, but zram usage itself. As mentioned in (2) kernel delays freeing of swapcache, but along with that it delays zram compressed page free also. i.e. there can be 2 copies, though one is compressed. This patch addresses these issues using two new flags QUEUE_FLAG_FAST and SWP_FAST, to indicate that accesses to the device will be fast and cheap, and instructs the swap layer to free up swap space agressively, and not to do read ahead. Change-Id: I5d2d5176a5f9420300bb2f843f6ecbdb25ea80e4 Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: D. Andrei Măceș <dmaces@nd.edu> Conflicts: include/linux/blkdev.h include/linux/swap.h mm/swap_state.c mm/swapfile.c Conflicts: include/linux/blkdev.h
* mm/zsmalloc: allocate exactly size of struct zs_poolGanesh Mahendran2016-01-051-3/+2
| | | | | | | | | | | | | | | In zs_create_pool(), we allocate memory more then sizeof(struct zs_pool) ovhd_size = roundup(sizeof(*pool), PAGE_SIZE); This patch allocate memory of exactly needed size. Change-Id: Id0ada356009c92bf791c94be073f4467f7bb1aac Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: correct fragile [kmap|kunmap]_atomic useMinchan Kim2016-01-051-9/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | The kunmap_atomic should use virtual address getting by kmap_atomic. However, some pieces of code in zsmalloc uses modified address, not the one got by kmap_atomic for kunmap_atomic. It's okay for working because zsmalloc modifies the address inner PAGE_SIZE bounday so it works with current kmap_atomic's implementation. But it's still fragile with potential changing of kmap_atomic so let's correct it. I got a subtle bug when I implemented a new feature of zsmalloc (compaction) due to a link's mishandling (the link was over page boundary). Although it was totally my mistake, it took a while to find the cause because an unpredictable kmapped address was unmapped causing an almost random crash. Change-Id: Ic637e7d65e743a42df5833566054634c9a08f86d Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: merge size_class to reduce fragmentationJoonsoo Kim2016-01-051-14/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | zsmalloc has many size_classes to reduce fragmentation and they are in 16 bytes unit, for example, 16, 32, 48, etc., if PAGE_SIZE is 4096. And, zsmalloc has constraint that each zspage has 4 pages at maximum. In this situation, we can see interesting aspect. Let's think about size_class for 1488, 1472, ..., 1376. To prevent external fragmentation, they uses 4 pages per zspage and so all they can contain 11 objects at maximum. 16384 (4096 * 4) = 1488 * 11 + remains 16384 (4096 * 4) = 1472 * 11 + remains 16384 (4096 * 4) = ... 16384 (4096 * 4) = 1376 * 11 + remains It means that they have same characteristics and classification between them isn't needed. If we use one size_class for them, we can reduce fragementation and save some memory since both the 1488 and 1472 sized classes can only fit 11 objects into 4 pages, and an object that's 1472 bytes can fit into an object that's 1488 bytes, merging these classes to always use objects that are 1488 bytes will reduce the total number of size classes. And reducing the total number of size classes reduces overall fragmentation, because a wider range of compressed pages can fit into a single size class, leaving less unused objects in each size class. For this purpose, this patch implement size_class merging. If there is size_class that have same pages_per_zspage and same number of objects per zspage with previous size_class, we don't create new size_class. Instead, we use previous, same characteristic size_class. With this way, above example sizes (1488, 1472, ..., 1376) use just one size_class so we can get much more memory utilization. Below is result of my simple test. TEST ENV: EXT4 on zram, mount with discard option WORKLOAD: untar kernel source code, remove directory in descending order in size. (drivers arch fs sound include net Documentation firmware kernel tools) Each line represents orig_data_size, compr_data_size, mem_used_total, fragmentation overhead (mem_used - compr_data_size) and overhead ratio (overhead to compr_data_size), respectively, after untar and remove operation is executed. * untar-nomerge.out orig_size compr_size used_size overhead overhead_ratio 525.88MB 199.16MB 210.23MB 11.08MB 5.56% 288.32MB 97.43MB 105.63MB 8.20MB 8.41% 177.32MB 61.12MB 69.40MB 8.28MB 13.55% 146.47MB 47.32MB 56.10MB 8.78MB 18.55% 124.16MB 38.85MB 48.41MB 9.55MB 24.58% 103.93MB 31.68MB 40.93MB 9.25MB 29.21% 84.34MB 22.86MB 32.72MB 9.86MB 43.13% 66.87MB 14.83MB 23.83MB 9.00MB 60.70% 60.67MB 11.11MB 18.60MB 7.49MB 67.48% 55.86MB 8.83MB 16.61MB 7.77MB 88.03% 53.32MB 8.01MB 15.32MB 7.31MB 91.24% * untar-merge.out orig_size compr_size used_size overhead overhead_ratio 526.23MB 199.18MB 209.81MB 10.64MB 5.34% 288.68MB 97.45MB 104.08MB 6.63MB 6.80% 177.68MB 61.14MB 66.93MB 5.79MB 9.47% 146.83MB 47.34MB 52.79MB 5.45MB 11.51% 124.52MB 38.87MB 44.30MB 5.43MB 13.96% 104.29MB 31.70MB 36.83MB 5.13MB 16.19% 84.70MB 22.88MB 27.92MB 5.04MB 22.04% 67.11MB 14.83MB 19.26MB 4.43MB 29.86% 60.82MB 11.10MB 14.90MB 3.79MB 34.17% 55.90MB 8.82MB 12.61MB 3.79MB 42.97% 53.32MB 8.01MB 11.73MB 3.73MB 46.53% As you can see above result, merged one has better utilization (overhead ratio, 5th column) and uses less memory (mem_used_total, 3rd column). Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Dan Streetman <ddstreet@ieee.org> Cc: Luigi Semenzato <semenzato@google.com> Cc: <juno.choi@lge.com> Cc: "seungho1.park" <seungho1.park@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: simplify init_zspage free obj linkingDan Streetman2016-01-051-9/+5
| | | | | | | | | | | | | | | | | | | | | | | Change zsmalloc init_zspage() logic to iterate through each object on each of its pages, checking the offset to verify the object is on the current page before linking it into the zspage. The current zsmalloc init_zspage free object linking code has logic that relies on there only being one page per zspage when PAGE_SIZE is a multiple of class->size. It calculates the number of objects for the current page, and iterates through all of them plus one, to account for the assumed partial object at the end of the page. While this currently works, the logic can be simplified to just link the object at each successive offset until the offset is larger than PAGE_SIZE, which does not rely on PAGE_SIZE being a multiple of class->size. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Seth Jennings <sjennings@variantweb.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: change return value unit of zs_get_total_size_bytesMinchan Kim2016-01-051-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | zs_get_total_size_bytes returns a amount of memory zsmalloc consumed with *byte unit* but zsmalloc operates *page unit* rather than byte unit so let's change the API so benefit we could get is that reduce unnecessary overhead (ie, change page unit with byte unit) in zsmalloc. Since return type is pages, "zs_get_total_pages" is better than "zs_get_total_size_bytes". Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Dan Streetman <ddstreet@ieee.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: <juno.choi@lge.com> Cc: <seungho1.park@lge.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: David Horner <ds2horner@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Conflicts: mm/zsmalloc.c Change-Id: If5697d7b7f8ebaab3b58c1f9f84de747eb909ca3
* zsmalloc: move pages_allocated to zs_poolMinchan Kim2016-01-051-15/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, zram has no feature to limit memory so theoretically zram can deplete system memory. Users have asked for a limit several times as even without exhaustion zram makes it hard to control memory usage of the platform. This patchset adds the feature. Patch 1 makes zs_get_total_size_bytes faster because it would be used frequently in later patches for the new feature. Patch 2 changes zs_get_total_size_bytes's return unit from bytes to page so that zsmalloc doesn't need unnecessary operation(ie, << PAGE_SHIFT). Patch 3 adds new feature. I added the feature into zram layer, not zsmalloc because limiation is zram's requirement, not zsmalloc so any other user using zsmalloc(ie, zpool) shouldn't affected by unnecessary branch of zsmalloc. In future, if every users of zsmalloc want the feature, then, we could move the feature from client side to zsmalloc easily but vice versa would be painful. Patch 4 adds news facility to report maximum memory usage of zram so that this avoids user polling frequently via /sys/block/zram0/ mem_used_total and ensures transient max are not missed. This patch (of 4): pages_allocated has counted in size_class structure and when user of zsmalloc want to see total_size_bytes, it should gather all of count from each size_class to report the sum. It's not bad if user don't see the value often but if user start to see the value frequently, it would be not a good deal for performance pov. This patch moves the count from size_class to zs_pool so it could reduce memory footprint (from [255 * 8byte] to [sizeof(atomic_long_t)]). Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Dan Streetman <ddstreet@ieee.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: <juno.choi@lge.com> Cc: <seungho1.park@lge.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Seth Jennings <sjennings@variantweb.net> Reviewed-by: David Horner <ds2horner@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: add copyrightMinchan Kim2016-01-051-0/+1
| | | | | | | | | Add my copyright to the zsmalloc source code which I maintain. Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zsmalloc: move it under mmMinchan Kim2016-01-053-0/+1132
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch moves zsmalloc under mm directory. Before that, description will explain why we have needed custom allocator. Zsmalloc is a new slab-based memory allocator for storing compressed pages. It is designed for low fragmentation and high allocation success rate on large object, but <= PAGE_SIZE allocations. zsmalloc differs from the kernel slab allocator in two primary ways to achieve these design goals. zsmalloc never requires high order page allocations to back slabs, or "size classes" in zsmalloc terms. Instead it allows multiple single-order pages to be stitched together into a "zspage" which backs the slab. This allows for higher allocation success rate under memory pressure. Also, zsmalloc allows objects to span page boundaries within the zspage. This allows for lower fragmentation than could be had with the kernel slab allocator for objects between PAGE_SIZE/2 and PAGE_SIZE. With the kernel slab allocator, if a page compresses to 60% of it original size, the memory savings gained through compression is lost in fragmentation because another object of the same size can't be stored in the leftover space. This ability to span pages results in zsmalloc allocations not being directly addressable by the user. The user is given an non-dereferencable handle in response to an allocation request. That handle must be mapped, using zs_map_object(), which returns a pointer to the mapped region that can be used. The mapping is necessary since the object data may reside in two different noncontigious pages. The zsmalloc fulfills the allocation needs for zram perfectly [sjenning@linux.vnet.ibm.com: borrow Seth's quote] Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Nitin Gupta <ngupta@vflare.org> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Bob Liu <bob.liu@oracle.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Luigi Semenzato <semenzato@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Pekka Enberg <penberg@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Change-Id: Ib026c17143131089494dc394c4a35e230220ec83 Conflicts: drivers/staging/Kconfig drivers/staging/Makefile
* mm: zcache/tmem/cleancache: s/flush/invalidate/Dan Magenheimer2016-01-051-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Complete the renaming from "flush" to "invalidate" across both tmem frontends (cleancache and frontswap) and both tmem backends (Xen and zcache), as required by akpm. This change is completely cosmetic. [v10: no change] [v9: akpm@linux-foundation.org: change "flush" to "invalidate", part 3] Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Jan Beulich <JBeulich@novell.com> Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Chris Mason <chris.mason@oracle.com> Cc: Rik Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> [v11: Remove the frontswap part] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Conflicts: drivers/xen/tmem.c include/linux/cleancache.h Change-Id: Id9661e5fc4bb6f416129f38c1e3df80319653041
* mm: reorder can_do_mlock to fix audit denialJeff Vander Stoep2015-04-111-2/+2
| | | | | | | | | | | | | | | | | | | | A userspace call to mmap(MAP_LOCKED) may result in the successful locking of memory while also producing a confusing audit log denial. can_do_mlock checks capable and rlimit. If either of these return positive can_do_mlock returns true. The capable check leads to an LSM hook used by apparmour and selinux which produce the audit denial. Reordering so rlimit is checked first eliminates the denial on success, only recording a denial when the lock is unsuccessful as a result of the denial. Signed-off-by: Jeff Vander Stoep <jeffv@google.com> Acked-by: Nick Kralevich <nnk@google.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Paul Cassella <cassella@cray.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* oom: do not kill tasks with oom_score_adj OOM_SCORE_ADJ_MINMichal Hocko2015-01-151-0/+5
| | | | | | | | | | | | | | | | | | | | | | | Commit c9f01245 ("oom: remove oom_disable_count") has removed the oom_disable_count counter which has been used for early break out from oom_badness so we could never select a task with oom_score_adj set to OOM_SCORE_ADJ_MIN (oom disabled). Now that the counter is gone we are always going through heuristics calculation and we always return a non zero positive value. This means that we can end up killing a task with OOM disabled because it is indistinguishable from regular tasks with 1% resp. CAP_SYS_ADMIN tasks with 3% usage of memory or tasks with oom_score_adj set but OOM enabled. Let's break out early if the task should have OOM disabled. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: remove oom_disable_countDavid Rientjes2015-01-151-18/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | This removes mm->oom_disable_count entirely since it's unnecessary and currently buggy. The counter was intended to be per-process but it's currently decremented in the exit path for each thread that exits, causing it to underflow. The count was originally intended to prevent oom killing threads that share memory with threads that cannot be killed since it doesn't lead to future memory freeing. The counter could be fixed to represent all threads sharing the same mm, but it's better to remove the count since: - it is possible that the OOM_DISABLE thread sharing memory with the victim is waiting on that thread to exit and will actually cause future memory freeing, and - there is no guarantee that a thread is disabled from oom killing just because another thread sharing its mm is oom disabled. Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Ying Han <yinghan@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>
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