- 07 7月, 2017 1 次提交
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由 Huang Ying 提交于
Patch series "THP swap: Delay splitting THP during swapping out", v11. This patchset is to optimize the performance of Transparent Huge Page (THP) swap. Recently, the performance of the storage devices improved so fast that we cannot saturate the disk bandwidth with single logical CPU when do page swap out even on a high-end server machine. Because the performance of the storage device improved faster than that of single logical CPU. And it seems that the trend will not change in the near future. On the other hand, the THP becomes more and more popular because of increased memory size. So it becomes necessary to optimize THP swap performance. The advantages of the THP swap support include: - Batch the swap operations for the THP to reduce lock acquiring/releasing, including allocating/freeing the swap space, adding/deleting to/from the swap cache, and writing/reading the swap space, etc. This will help improve the performance of the THP swap. - The THP swap space read/write will be 2M sequential IO. It is particularly helpful for the swap read, which are usually 4k random IO. This will improve the performance of the THP swap too. - It will help the memory fragmentation, especially when the THP is heavily used by the applications. The 2M continuous pages will be free up after THP swapping out. - It will improve the THP utilization on the system with the swap turned on. Because the speed for khugepaged to collapse the normal pages into the THP is quite slow. After the THP is split during the swapping out, it will take quite long time for the normal pages to collapse back into the THP after being swapped in. The high THP utilization helps the efficiency of the page based memory management too. There are some concerns regarding THP swap in, mainly because possible enlarged read/write IO size (for swap in/out) may put more overhead on the storage device. To deal with that, the THP swap in should be turned on only when necessary. For example, it can be selected via "always/never/madvise" logic, to be turned on globally, turned off globally, or turned on only for VMA with MADV_HUGEPAGE, etc. This patchset is the first step for the THP swap support. The plan is to delay splitting THP step by step, finally avoid splitting THP during the THP swapping out and swap out/in the THP as a whole. As the first step, in this patchset, the splitting huge page is delayed from almost the first step of swapping out to after allocating the swap space for the THP and adding the THP into the swap cache. This will reduce lock acquiring/releasing for the locks used for the swap cache management. With the patchset, the swap out throughput improves 15.5% (from about 3.73GB/s to about 4.31GB/s) in the vm-scalability swap-w-seq test case with 8 processes. The test is done on a Xeon E5 v3 system. The swap device used is a RAM simulated PMEM (persistent memory) device. To test the sequential swapping out, the test case creates 8 processes, which sequentially allocate and write to the anonymous pages until the RAM and part of the swap device is used up. This patch (of 5): In this patch, splitting huge page is delayed from almost the first step of swapping out to after allocating the swap space for the THP (Transparent Huge Page) and adding the THP into the swap cache. This will batch the corresponding operation, thus improve THP swap out throughput. This is the first step for the THP swap optimization. The plan is to delay splitting the THP step by step and avoid splitting the THP finally. In this patch, one swap cluster is used to hold the contents of each THP swapped out. So, the size of the swap cluster is changed to that of the THP (Transparent Huge Page) on x86_64 architecture (512). For other architectures which want such THP swap optimization, ARCH_USES_THP_SWAP_CLUSTER needs to be selected in the Kconfig file for the architecture. In effect, this will enlarge swap cluster size by 2 times on x86_64. Which may make it harder to find a free cluster when the swap space becomes fragmented. So that, this may reduce the continuous swap space allocation and sequential write in theory. The performance test in 0day shows no regressions caused by this. In the future of THP swap optimization, some information of the swapped out THP (such as compound map count) will be recorded in the swap_cluster_info data structure. The mem cgroup swap accounting functions are enhanced to support charge or uncharge a swap cluster backing a THP as a whole. The swap cluster allocate/free functions are added to allocate/free a swap cluster for a THP. A fair simple algorithm is used for swap cluster allocation, that is, only the first swap device in priority list will be tried to allocate the swap cluster. The function will fail if the trying is not successful, and the caller will fallback to allocate a single swap slot instead. This works good enough for normal cases. If the difference of the number of the free swap clusters among multiple swap devices is significant, it is possible that some THPs are split earlier than necessary. For example, this could be caused by big size difference among multiple swap devices. The swap cache functions is enhanced to support add/delete THP to/from the swap cache as a set of (HPAGE_PMD_NR) sub-pages. This may be enhanced in the future with multi-order radix tree. But because we will split the THP soon during swapping out, that optimization doesn't make much sense for this first step. The THP splitting functions are enhanced to support to split THP in swap cache during swapping out. The page lock will be held during allocating the swap cluster, adding the THP into the swap cache and splitting the THP. So in the code path other than swapping out, if the THP need to be split, the PageSwapCache(THP) will be always false. The swap cluster is only available for SSD, so the THP swap optimization in this patchset has no effect for HDD. [ying.huang@intel.com: fix two issues in THP optimize patch] Link: http://lkml.kernel.org/r/87k25ed8zo.fsf@yhuang-dev.intel.com [hannes@cmpxchg.org: extensive cleanups and simplifications, reduce code size] Link: http://lkml.kernel.org/r/20170515112522.32457-2-ying.huang@intel.comSigned-off-by: N"Huang, Ying" <ying.huang@intel.com> Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Suggested-by: Andrew Morton <akpm@linux-foundation.org> [for config option] Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> [for changes in huge_memory.c and huge_mm.h] Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 20 6月, 2017 2 次提交
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由 Ingo Molnar 提交于
So I've noticed a number of instances where it was not obvious from the code whether ->task_list was for a wait-queue head or a wait-queue entry. Furthermore, there's a number of wait-queue users where the lists are not for 'tasks' but other entities (poll tables, etc.), in which case the 'task_list' name is actively confusing. To clear this all up, name the wait-queue head and entry list structure fields unambiguously: struct wait_queue_head::task_list => ::head struct wait_queue_entry::task_list => ::entry For example, this code: rqw->wait.task_list.next != &wait->task_list ... is was pretty unclear (to me) what it's doing, while now it's written this way: rqw->wait.head.next != &wait->entry ... which makes it pretty clear that we are iterating a list until we see the head. Other examples are: list_for_each_entry_safe(pos, next, &x->task_list, task_list) { list_for_each_entry(wq, &fence->wait.task_list, task_list) { ... where it's unclear (to me) what we are iterating, and during review it's hard to tell whether it's trying to walk a wait-queue entry (which would be a bug), while now it's written as: list_for_each_entry_safe(pos, next, &x->head, entry) { list_for_each_entry(wq, &fence->wait.head, entry) { Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Ingo Molnar 提交于
Rename: wait_queue_t => wait_queue_entry_t 'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue", but in reality it's a queue *entry*. The 'real' queue is the wait queue head, which had to carry the name. Start sorting this out by renaming it to 'wait_queue_entry_t'. This also allows the real structure name 'struct __wait_queue' to lose its double underscore and become 'struct wait_queue_entry', which is the more canonical nomenclature for such data types. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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- 13 5月, 2017 1 次提交
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由 Michal Hocko 提交于
Laurent Dufour has noticed that hwpoinsoned pages are kept charged. In his particular case he has hit a bad_page("page still charged to cgroup") when onlining a hwpoison page. While this looks like something that shouldn't happen in the first place because onlining hwpages and returning them to the page allocator makes only little sense it shows a real problem. hwpoison pages do not get freed usually so we do not uncharge them (at least not since commit 0a31bc97 ("mm: memcontrol: rewrite uncharge API")). Each charge pins memcg (since e8ea14cc ("mm: memcontrol: take a css reference for each charged page")) as well and so the mem_cgroup and the associated state will never go away. Fix this leak by forcibly uncharging a LRU hwpoisoned page in delete_from_lru_cache(). We also have to tweak uncharge_list because it cannot rely on zero ref count for these pages. [akpm@linux-foundation.org: coding-style fixes] Fixes: 0a31bc97 ("mm: memcontrol: rewrite uncharge API") Link: http://lkml.kernel.org/r/20170502185507.GB19165@dhcp22.suse.czSigned-off-by: NMichal Hocko <mhocko@suse.com> Reported-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com> Tested-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com> Reviewed-by: NBalbir Singh <bsingharora@gmail.com> Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 04 5月, 2017 6 次提交
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由 Johannes Weiner 提交于
The memory controllers stat function names are awkwardly long and arbitrarily different from the zone and node stat functions. The current interface is named: mem_cgroup_read_stat() mem_cgroup_update_stat() mem_cgroup_inc_stat() mem_cgroup_dec_stat() mem_cgroup_update_page_stat() mem_cgroup_inc_page_stat() mem_cgroup_dec_page_stat() This patch renames it to match the corresponding node stat functions: memcg_page_state() [node_page_state()] mod_memcg_state() [mod_node_state()] inc_memcg_state() [inc_node_state()] dec_memcg_state() [dec_node_state()] mod_memcg_page_state() [mod_node_page_state()] inc_memcg_page_state() [inc_node_page_state()] dec_memcg_page_state() [dec_node_page_state()] Link: http://lkml.kernel.org/r/20170404220148.28338-4-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NVladimir Davydov <vdavydov.dev@gmail.com> Acked-by: NMichal Hocko <mhocko@suse.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
The current duplication is a high-maintenance mess, and it's painful to add new items or query memcg state from the rest of the VM. This increases the size of the stat array marginally, but we should aim to track all these stats on a per-cgroup level anyway. Link: http://lkml.kernel.org/r/20170404220148.28338-3-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NVladimir Davydov <vdavydov.dev@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
The current duplication is a high-maintenance mess, and it's painful to add new items. This increases the size of the event array, but we'll eventually want most of the VM events tracked on a per-cgroup basis anyway. Link: http://lkml.kernel.org/r/20170404220148.28338-2-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NVladimir Davydov <vdavydov.dev@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
We only ever count single events, drop the @nr parameter. Rename the function accordingly. Remove low-information kerneldoc. Link: http://lkml.kernel.org/r/20170404220148.28338-1-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NVladimir Davydov <vdavydov.dev@gmail.com> Acked-by: NMichal Hocko <mhocko@suse.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
Since commit 59dc76b0 ("mm: vmscan: reduce size of inactive file list") we noticed bigger IO spikes during changes in cache access patterns. The patch in question shrunk the inactive list size to leave more room for the current workingset in the presence of streaming IO. However, workingset transitions that previously happened on the inactive list are now pushed out of memory and incur more refaults to complete. This patch disables active list protection when refaults are being observed. This accelerates workingset transitions, and allows more of the new set to establish itself from memory, without eating into the ability to protect the established workingset during stable periods. The workloads that were measurably affected for us were hit pretty bad by it, with refault/majfault rates doubling and tripling during cache transitions, and the machines sustaining half-hour periods of 100% IO utilization, where they'd previously have sub-minute peaks at 60-90%. Stateful services that handle user data tend to be more conservative with kernel upgrades. As a result we hit most page cache issues with some delay, as was the case here. The severity seemed to warrant a stable tag. Fixes: 59dc76b0 ("mm: vmscan: reduce size of inactive file list") Link: http://lkml.kernel.org/r/20170404220052.27593-1-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: <stable@vger.kernel.org> [4.7+] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
Cgroups currently don't report how much shmem they use, which can be useful data to have, in particular since shmem is included in the cache/file item while being reclaimed like anonymous memory. Add a counter to track shmem pages during charging and uncharging. Link: http://lkml.kernel.org/r/20170221164343.32252-1-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Reported-by: NChris Down <cdown@fb.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 10 3月, 2017 2 次提交
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由 Tahsin Erdogan 提交于
mem_cgroup_free() indirectly calls wb_domain_exit() which is not prepared to deal with a struct wb_domain object that hasn't executed wb_domain_init(). For instance, the following warning message is printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc(): INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x67/0x99 register_lock_class+0x36d/0x540 __lock_acquire+0x7f/0x1a30 lock_acquire+0xcc/0x200 del_timer_sync+0x3c/0xc0 wb_domain_exit+0x14/0x20 mem_cgroup_free+0x14/0x40 mem_cgroup_css_alloc+0x3f9/0x620 cgroup_apply_control_enable+0x190/0x390 cgroup_mkdir+0x290/0x3d0 kernfs_iop_mkdir+0x58/0x80 vfs_mkdir+0x10e/0x1a0 SyS_mkdirat+0xa8/0xd0 SyS_mkdir+0x14/0x20 entry_SYSCALL_64_fastpath+0x18/0xad Add __mem_cgroup_free() which skips wb_domain_exit(). This is used by both mem_cgroup_free() and mem_cgroup_alloc() clean up. Fixes: 0b8f73e1 ("mm: memcontrol: clean up alloc, online, offline, free functions") Link: http://lkml.kernel.org/r/20170306192122.24262-1-tahsin@google.comSigned-off-by: NTahsin Erdogan <tahsin@google.com> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Laurent Dufour 提交于
The system may panic when initialisation is done when almost all the memory is assigned to the huge pages using the kernel command line parameter hugepage=xxxx. Panic may occur like this: Unable to handle kernel paging request for data at address 0x00000000 Faulting instruction address: 0xc000000000302b88 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 [ 0.082424] NUMA pSeries Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-15-generic #16-Ubuntu task: c00000021ed01600 task.stack: c00000010d108000 NIP: c000000000302b88 LR: c000000000270e04 CTR: c00000000016cfd0 REGS: c00000010d10b2c0 TRAP: 0300 Not tainted (4.9.0-15-generic) MSR: 8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE>[ 0.082770] CR: 28424422 XER: 00000000 CFAR: c0000000003d28b8 DAR: 0000000000000000 DSISR: 40000000 SOFTE: 1 GPR00: c000000000270e04 c00000010d10b540 c00000000141a300 c00000010fff6300 GPR04: 0000000000000000 00000000026012c0 c00000010d10b630 0000000487ab0000 GPR08: 000000010ee90000 c000000001454fd8 0000000000000000 0000000000000000 GPR12: 0000000000004400 c00000000fb80000 00000000026012c0 00000000026012c0 GPR16: 00000000026012c0 0000000000000000 0000000000000000 0000000000000002 GPR20: 000000000000000c 0000000000000000 0000000000000000 00000000024200c0 GPR24: c0000000016eef48 0000000000000000 c00000010fff7d00 00000000026012c0 GPR28: 0000000000000000 c00000010fff7d00 c00000010fff6300 c00000010d10b6d0 NIP mem_cgroup_soft_limit_reclaim+0xf8/0x4f0 LR do_try_to_free_pages+0x1b4/0x450 Call Trace: do_try_to_free_pages+0x1b4/0x450 try_to_free_pages+0xf8/0x270 __alloc_pages_nodemask+0x7a8/0xff0 new_slab+0x104/0x8e0 ___slab_alloc+0x620/0x700 __slab_alloc+0x34/0x60 kmem_cache_alloc_node_trace+0xdc/0x310 mem_cgroup_init+0x158/0x1c8 do_one_initcall+0x68/0x1d0 kernel_init_freeable+0x278/0x360 kernel_init+0x24/0x170 ret_from_kernel_thread+0x5c/0x74 Instruction dump: eb81ffe0 eba1ffe8 ebc1fff0 ebe1fff8 4e800020 3d230001 e9499a42 3d220004 3929acd8 794a1f24 7d295214 eac90100 <e9360000> 2fa90000 419eff74 3b200000 ---[ end trace 342f5208b00d01b6 ]--- This is a chicken and egg issue where the kernel try to get free memory when allocating per node data in mem_cgroup_init(), but in that path mem_cgroup_soft_limit_reclaim() is called which assumes that these data are allocated. As mem_cgroup_soft_limit_reclaim() is best effort, it should return when these data are not yet allocated. This patch also fixes potential null pointer access in mem_cgroup_remove_from_trees() and mem_cgroup_update_tree(). Link: http://lkml.kernel.org/r/1487856999-16581-2-git-send-email-ldufour@linux.vnet.ibm.comSigned-off-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com> Acked-by: NMichal Hocko <mhocko@suse.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NBalbir Singh <bsingharora@gmail.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 02 3月, 2017 1 次提交
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由 Ingo Molnar 提交于
We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/mm.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. The APIs that are going to be moved first are: mm_alloc() __mmdrop() mmdrop() mmdrop_async_fn() mmdrop_async() mmget_not_zero() mmput() mmput_async() get_task_mm() mm_access() mm_release() Include the new header in the files that are going to need it. Acked-by: NLinus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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- 25 2月, 2017 1 次提交
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由 Hugh Dickins 提交于
Remove the prototypes for shmem_mapping() and shmem_zero_setup() from linux/mm.h, since they are already provided in linux/shmem_fs.h. But shmem_fs.h must then provide the inline stub for shmem_mapping() when CONFIG_SHMEM is not set, and a few more cfiles now need to #include it. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1702081658250.1549@eggly.anvilsSigned-off-by: NHugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 23 2月, 2017 2 次提交
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由 Tejun Heo 提交于
If there's contention on slab_mutex, queueing the per-cache destruction work item on the system_wq can unnecessarily create and tie up a lot of kworkers. Rename memcg_kmem_cache_create_wq to memcg_kmem_cache_wq and make it global and use that workqueue for the destruction work items too. While at it, convert the workqueue from an unbound workqueue to a per-cpu one with concurrency limited to 1. It's generally preferable to use per-cpu workqueues and concurrency limit of 1 is safe enough. This is suggested by Joonsoo Kim. Link: http://lkml.kernel.org/r/20170117235411.9408-11-tj@kernel.orgSigned-off-by: NTejun Heo <tj@kernel.org> Reported-by: NJay Vana <jsvana@fb.com> Acked-by: NVladimir Davydov <vdavydov@tarantool.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Tejun Heo 提交于
With kmem cgroup support enabled, kmem_caches can be created and destroyed frequently and a great number of near empty kmem_caches can accumulate if there are a lot of transient cgroups and the system is not under memory pressure. When memory reclaim starts under such conditions, it can lead to consecutive deactivation and destruction of many kmem_caches, easily hundreds of thousands on moderately large systems, exposing scalability issues in the current slab management code. This is one of the patches to address the issue. While a memcg kmem_cache is listed on its root cache's ->children list, there is no direct way to iterate all kmem_caches which are assocaited with a memory cgroup. The only way to iterate them is walking all caches while filtering out caches which don't match, which would be most of them. This makes memcg destruction operations O(N^2) where N is the total number of slab caches which can be huge. This combined with the synchronous RCU operations can tie up a CPU and affect the whole machine for many hours when memory reclaim triggers offlining and destruction of the stale memcgs. This patch adds mem_cgroup->kmem_caches list which goes through memcg_cache_params->kmem_caches_node of all kmem_caches which are associated with the memcg. All memcg specific iterations, including stat file access, are updated to use the new list instead. Link: http://lkml.kernel.org/r/20170117235411.9408-6-tj@kernel.orgSigned-off-by: NTejun Heo <tj@kernel.org> Reported-by: NJay Vana <jsvana@fb.com> Acked-by: NVladimir Davydov <vdavydov.dev@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 25 1月, 2017 1 次提交
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由 David Rientjes 提交于
When memory.move_charge_at_immigrate is enabled and precharges are depleted during move, mem_cgroup_move_charge_pte_range() will attempt to increase the size of the precharge. Prevent precharges from ever looping by setting __GFP_NORETRY. This was probably the intention of the GFP_KERNEL & ~__GFP_NORETRY, which is pointless as written. Fixes: 0029e19e ("mm: memcontrol: remove explicit OOM parameter in charge path") Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1701130208510.69402@chino.kir.corp.google.comSigned-off-by: NDavid Rientjes <rientjes@google.com> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 11 1月, 2017 1 次提交
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由 Michal Hocko 提交于
Nils Holland and Klaus Ethgen have reported unexpected OOM killer invocations with 32b kernel starting with 4.8 kernels kworker/u4:5 invoked oom-killer: gfp_mask=0x2400840(GFP_NOFS|__GFP_NOFAIL), nodemask=0, order=0, oom_score_adj=0 kworker/u4:5 cpuset=/ mems_allowed=0 CPU: 1 PID: 2603 Comm: kworker/u4:5 Not tainted 4.9.0-gentoo #2 [...] Mem-Info: active_anon:58685 inactive_anon:90 isolated_anon:0 active_file:274324 inactive_file:281962 isolated_file:0 unevictable:0 dirty:649 writeback:0 unstable:0 slab_reclaimable:40662 slab_unreclaimable:17754 mapped:7382 shmem:202 pagetables:351 bounce:0 free:206736 free_pcp:332 free_cma:0 Node 0 active_anon:234740kB inactive_anon:360kB active_file:1097296kB inactive_file:1127848kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:29528kB dirty:2596kB writeback:0kB shmem:0kB shmem_thp: 0kB shmem_pmdmapped: 184320kB anon_thp: 808kB writeback_tmp:0kB unstable:0kB pages_scanned:0 all_unreclaimable? no DMA free:3952kB min:788kB low:984kB high:1180kB active_anon:0kB inactive_anon:0kB active_file:7316kB inactive_file:0kB unevictable:0kB writepending:96kB present:15992kB managed:15916kB mlocked:0kB slab_reclaimable:3200kB slab_unreclaimable:1408kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 813 3474 3474 Normal free:41332kB min:41368kB low:51708kB high:62048kB active_anon:0kB inactive_anon:0kB active_file:532748kB inactive_file:44kB unevictable:0kB writepending:24kB present:897016kB managed:836248kB mlocked:0kB slab_reclaimable:159448kB slab_unreclaimable:69608kB kernel_stack:1112kB pagetables:1404kB bounce:0kB free_pcp:528kB local_pcp:340kB free_cma:0kB lowmem_reserve[]: 0 0 21292 21292 HighMem free:781660kB min:512kB low:34356kB high:68200kB active_anon:234740kB inactive_anon:360kB active_file:557232kB inactive_file:1127804kB unevictable:0kB writepending:2592kB present:2725384kB managed:2725384kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:800kB local_pcp:608kB free_cma:0kB the oom killer is clearly pre-mature because there there is still a lot of page cache in the zone Normal which should satisfy this lowmem request. Further debugging has shown that the reclaim cannot make any forward progress because the page cache is hidden in the active list which doesn't get rotated because inactive_list_is_low is not memcg aware. The code simply subtracts per-zone highmem counters from the respective memcg's lru sizes which doesn't make any sense. We can simply end up always seeing the resulting active and inactive counts 0 and return false. This issue is not limited to 32b kernels but in practice the effect on systems without CONFIG_HIGHMEM would be much harder to notice because we do not invoke the OOM killer for allocations requests targeting < ZONE_NORMAL. Fix the issue by tracking per zone lru page counts in mem_cgroup_per_node and subtract per-memcg highmem counts when memcg is enabled. Introduce helper lruvec_zone_lru_size which redirects to either zone counters or mem_cgroup_get_zone_lru_size when appropriate. We are losing empty LRU but non-zero lru size detection introduced by ca707239 ("mm: update_lru_size warn and reset bad lru_size") because of the inherent zone vs. node discrepancy. Fixes: f8d1a311 ("mm: consider whether to decivate based on eligible zones inactive ratio") Link: http://lkml.kernel.org/r/20170104100825.3729-1-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com> Reported-by: NNils Holland <nholland@tisys.org> Tested-by: NNils Holland <nholland@tisys.org> Reported-by: NKlaus Ethgen <Klaus@Ethgen.de> Acked-by: NMinchan Kim <minchan@kernel.org> Acked-by: NMel Gorman <mgorman@suse.de> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Reviewed-by: NVladimir Davydov <vdavydov.dev@gmail.com> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 25 12月, 2016 1 次提交
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由 Linus Torvalds 提交于
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: NAl Viro <viro@zeniv.linux.org.uk> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 13 12月, 2016 1 次提交
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由 Vladimir Davydov 提交于
Creating a lot of cgroups at the same time might stall all worker threads with kmem cache creation works, because kmem cache creation is done with the slab_mutex held. The problem was amplified by commits 801faf0d ("mm/slab: lockless decision to grow cache") in case of SLAB and 81ae6d03 ("mm/slub.c: replace kick_all_cpus_sync() with synchronize_sched() in kmem_cache_shrink()") in case of SLUB, which increased the maximal time the slab_mutex can be held. To prevent that from happening, let's use a special ordered single threaded workqueue for kmem cache creation. This shouldn't introduce any functional changes regarding how kmem caches are created, as the work function holds the global slab_mutex during its whole runtime anyway, making it impossible to run more than one work at a time. By using a single threaded workqueue, we just avoid creating a thread per each work. Ordering is required to avoid a situation when a cgroup's work is put off indefinitely because there are other cgroups to serve, in other words to guarantee fairness. Link: https://bugzilla.kernel.org/show_bug.cgi?id=172981 Link: http://lkml.kernel.org/r/20161004131417.GC1862@esperanzaSigned-off-by: NVladimir Davydov <vdavydov.dev@gmail.com> Reported-by: NDoug Smythies <dsmythies@telus.net> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 10 11月, 2016 1 次提交
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Install the callbacks via the state machine. Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: linux-mm@kvack.org Cc: rt@linutronix.de Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: cgroups@vger.kernel.org Link: http://lkml.kernel.org/r/20161103145021.28528-4-bigeasy@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 28 10月, 2016 1 次提交
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由 Johannes Weiner 提交于
On 4.0, we saw a stack corruption from a page fault entering direct memory cgroup reclaim, calling into btrfs_releasepage(), which then tried to allocate an extent and recursed back into a kmem charge ad nauseam: [...] btrfs_releasepage+0x2c/0x30 try_to_release_page+0x32/0x50 shrink_page_list+0x6da/0x7a0 shrink_inactive_list+0x1e5/0x510 shrink_lruvec+0x605/0x7f0 shrink_zone+0xee/0x320 do_try_to_free_pages+0x174/0x440 try_to_free_mem_cgroup_pages+0xa7/0x130 try_charge+0x17b/0x830 memcg_charge_kmem+0x40/0x80 new_slab+0x2d9/0x5a0 __slab_alloc+0x2fd/0x44f kmem_cache_alloc+0x193/0x1e0 alloc_extent_state+0x21/0xc0 __clear_extent_bit+0x2b5/0x400 try_release_extent_mapping+0x1a3/0x220 __btrfs_releasepage+0x31/0x70 btrfs_releasepage+0x2c/0x30 try_to_release_page+0x32/0x50 shrink_page_list+0x6da/0x7a0 shrink_inactive_list+0x1e5/0x510 shrink_lruvec+0x605/0x7f0 shrink_zone+0xee/0x320 do_try_to_free_pages+0x174/0x440 try_to_free_mem_cgroup_pages+0xa7/0x130 try_charge+0x17b/0x830 mem_cgroup_try_charge+0x65/0x1c0 handle_mm_fault+0x117f/0x1510 __do_page_fault+0x177/0x420 do_page_fault+0xc/0x10 page_fault+0x22/0x30 On later kernels, kmem charging is opt-in rather than opt-out, and that particular kmem allocation in btrfs_releasepage() is no longer being charged and won't recurse and overrun the stack anymore. But it's not impossible for an accounted allocation to happen from the memcg direct reclaim context, and we needed to reproduce this crash many times before we even got a useful stack trace out of it. Like other direct reclaimers, mark tasks in memcg reclaim PF_MEMALLOC to avoid recursing into any other form of direct reclaim. Then let recursive charges from PF_MEMALLOC contexts bypass the cgroup limit. Link: http://lkml.kernel.org/r/20161025141050.GA13019@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 08 10月, 2016 5 次提交
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由 Johannes Weiner 提交于
The cgroup core and the memory controller need to track socket ownership for different purposes, but the tracking sites being entirely different is kind of ugly. Be a better citizen and rename the memory controller callbacks to match the cgroup core callbacks, then move them to the same place. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20160914194846.11153-3-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NTejun Heo <tj@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Huang Ying 提交于
This patch is to improve the performance of swap cache operations when the type of the swap device is not 0. Originally, the whole swap entry value is used as the key of the swap cache, even though there is one radix tree for each swap device. If the type of the swap device is not 0, the height of the radix tree of the swap cache will be increased unnecessary, especially on 64bit architecture. For example, for a 1GB swap device on the x86_64 architecture, the height of the radix tree of the swap cache is 11. But if the offset of the swap entry is used as the key of the swap cache, the height of the radix tree of the swap cache is 4. The increased height causes unnecessary radix tree descending and increased cache footprint. This patch reduces the height of the radix tree of the swap cache via using the offset of the swap entry instead of the whole swap entry value as the key of the swap cache. In 32 processes sequential swap out test case on a Xeon E5 v3 system with RAM disk as swap, the lock contention for the spinlock of the swap cache is reduced from 20.15% to 12.19%, when the type of the swap device is 1. Use the whole swap entry as key, perf-profile.calltrace.cycles-pp._raw_spin_lock_irq.__add_to_swap_cache.add_to_swap_cache.add_to_swap.shrink_page_list: 10.37, perf-profile.calltrace.cycles-pp._raw_spin_lock_irqsave.__remove_mapping.shrink_page_list.shrink_inactive_list.shrink_node_memcg: 9.78, Use the swap offset as key, perf-profile.calltrace.cycles-pp._raw_spin_lock_irq.__add_to_swap_cache.add_to_swap_cache.add_to_swap.shrink_page_list: 6.25, perf-profile.calltrace.cycles-pp._raw_spin_lock_irqsave.__remove_mapping.shrink_page_list.shrink_inactive_list.shrink_node_memcg: 5.94, Link: http://lkml.kernel.org/r/1473270649-27229-1-git-send-email-ying.huang@intel.comSigned-off-by: N"Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Aaron Lu <aaron.lu@intel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 James Morse 提交于
mem_cgroup_count_precharge() and mem_cgroup_move_charge() both call walk_page_range() on the range 0 to ~0UL, neither provide a pte_hole callback, which causes the current implementation to skip non-vma regions. This is all fine but follow up changes would like to make walk_page_range more generic so it is better to be explicit about which range to traverse so let's use highest_vm_end to explicitly traverse only user mmaped memory. [mhocko@kernel.org: rewrote changelog] Link: http://lkml.kernel.org/r/1472655897-22532-1-git-send-email-james.morse@arm.comSigned-off-by: NJames Morse <james.morse@arm.com> Acked-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Vladimir Davydov 提交于
Link: http://lkml.kernel.org/r/1c5ddb1c171dbdfc3262252769d6138a29b35b70.1470219853.git.vdavydov@virtuozzo.comSigned-off-by: NVladimir Davydov <vdavydov@virtuozzo.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NMichal Hocko <mhocko@suse.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Vladimir Davydov 提交于
When selecting an oom victim, we use the same heuristic for both memory cgroup and global oom. The only difference is the scope of tasks to select the victim from. So we could just export an iterator over all memcg tasks and keep all oom related logic in oom_kill.c, but instead we duplicate pieces of it in memcontrol.c reusing some initially private functions of oom_kill.c in order to not duplicate all of it. That looks ugly and error prone, because any modification of select_bad_process should also be propagated to mem_cgroup_out_of_memory. Let's rework this as follows: keep all oom heuristic related code private to oom_kill.c and make oom_kill.c use exported memcg functions when it's really necessary (like in case of iterating over memcg tasks). Link: http://lkml.kernel.org/r/1470056933-7505-1-git-send-email-vdavydov@virtuozzo.comSigned-off-by: NVladimir Davydov <vdavydov@virtuozzo.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 20 9月, 2016 1 次提交
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由 Johannes Weiner 提交于
During cgroup2 rollout into production, we started encountering css refcount underflows and css access crashes in the memory controller. Splitting the heavily shared css reference counter into logical users narrowed the imbalance down to the cgroup2 socket memory accounting. The problem turns out to be the per-cpu charge cache. Cgroup1 had a separate socket counter, but the new cgroup2 socket accounting goes through the common charge path that uses a shared per-cpu cache for all memory that is being tracked. Those caches are safe against scheduling preemption, but not against interrupts - such as the newly added packet receive path. When cache draining is interrupted by network RX taking pages out of the cache, the resuming drain operation will put references of in-use pages, thus causing the imbalance. Disable IRQs during all per-cpu charge cache operations. Fixes: f7e1cb6e ("mm: memcontrol: account socket memory in unified hierarchy memory controller") Link: http://lkml.kernel.org/r/20160914194846.11153-1-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NTejun Heo <tj@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: <stable@vger.kernel.org> [4.5+] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 27 8月, 2016 1 次提交
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由 Arnd Bergmann 提交于
A bugfix in v4.8-rc2 introduced a harmless warning when CONFIG_MEMCG_SWAP is disabled but CONFIG_MEMCG is enabled: mm/memcontrol.c:4085:27: error: 'mem_cgroup_id_get_online' defined but not used [-Werror=unused-function] static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) This moves the function inside of the #ifdef block that hides the calling function, to avoid the warning. Fixes: 1f47b61f ("mm: memcontrol: fix swap counter leak on swapout from offline cgroup") Link: http://lkml.kernel.org/r/20160824113733.2776701-1-arnd@arndb.deSigned-off-by: NArnd Bergmann <arnd@arndb.de> Acked-by: NMichal Hocko <mhocko@suse.com> Acked-by: NVladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 8月, 2016 2 次提交
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由 Vladimir Davydov 提交于
Since commit 73f576c0 ("mm: memcontrol: fix cgroup creation failure after many small jobs") swap entries do not pin memcg->css.refcnt directly. Instead, they pin memcg->id.ref. So we should adjust the reference counters accordingly when moving swap charges between cgroups. Fixes: 73f576c0 ("mm: memcontrol: fix cgroup creation failure after many small jobs") Link: http://lkml.kernel.org/r/9ce297c64954a42dc90b543bc76106c4a94f07e8.1470219853.git.vdavydov@virtuozzo.comSigned-off-by: NVladimir Davydov <vdavydov@virtuozzo.com> Acked-by: NMichal Hocko <mhocko@suse.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [3.19+] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Vladimir Davydov 提交于
An offline memory cgroup might have anonymous memory or shmem left charged to it and no swap. Since only swap entries pin the id of an offline cgroup, such a cgroup will have no id and so an attempt to swapout its anon/shmem will not store memory cgroup info in the swap cgroup map. As a result, memcg->swap or memcg->memsw will never get uncharged from it and any of its ascendants. Fix this by always charging swapout to the first ancestor cgroup that hasn't released its id yet. [hannes@cmpxchg.org: add comment to mem_cgroup_swapout] [vdavydov@virtuozzo.com: use WARN_ON_ONCE() in mem_cgroup_id_get_online()] Link: http://lkml.kernel.org/r/20160803123445.GJ13263@esperanza Fixes: 73f576c0 ("mm: memcontrol: fix cgroup creation failure after many small jobs") Link: http://lkml.kernel.org/r/5336daa5c9a32e776067773d9da655d2dc126491.1470219853.git.vdavydov@virtuozzo.comSigned-off-by: NVladimir Davydov <vdavydov@virtuozzo.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> [3.19+] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 10 8月, 2016 1 次提交
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由 Vladimir Davydov 提交于
To distinguish non-slab pages charged to kmemcg we mark them PageKmemcg, which sets page->_mapcount to -512. Currently, we set/clear PageKmemcg in __alloc_pages_nodemask()/free_pages_prepare() for any page allocated with __GFP_ACCOUNT, including those that aren't actually charged to any cgroup, i.e. allocated from the root cgroup context. To avoid overhead in case cgroups are not used, we only do that if memcg_kmem_enabled() is true. The latter is set iff there are kmem-enabled memory cgroups (online or offline). The root cgroup is not considered kmem-enabled. As a result, if a page is allocated with __GFP_ACCOUNT for the root cgroup when there are kmem-enabled memory cgroups and is freed after all kmem-enabled memory cgroups were removed, e.g. # no memory cgroups has been created yet, create one mkdir /sys/fs/cgroup/memory/test # run something allocating pages with __GFP_ACCOUNT, e.g. # a program using pipe dmesg | tail # remove the memory cgroup rmdir /sys/fs/cgroup/memory/test we'll get bad page state bug complaining about page->_mapcount != -1: BUG: Bad page state in process swapper/0 pfn:1fd945c page:ffffea007f651700 count:0 mapcount:-511 mapping: (null) index:0x0 flags: 0x1000000000000000() To avoid that, let's mark with PageKmemcg only those pages that are actually charged to and hence pin a non-root memory cgroup. Fixes: 4949148a ("mm: charge/uncharge kmemcg from generic page allocator paths") Reported-and-tested-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NVladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 03 8月, 2016 1 次提交
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由 Michal Hocko 提交于
We've had a report about soft lockups caused by lock bouncing in the soft reclaim path: BUG: soft lockup - CPU#0 stuck for 22s! [kav4proxy-kavic:3128] RIP: 0010:[<ffffffff81469798>] [<ffffffff81469798>] _raw_spin_lock+0x18/0x20 Call Trace: mem_cgroup_soft_limit_reclaim+0x25a/0x280 shrink_zones+0xed/0x200 do_try_to_free_pages+0x74/0x320 try_to_free_pages+0x112/0x180 __alloc_pages_slowpath+0x3ff/0x820 __alloc_pages_nodemask+0x1e9/0x200 alloc_pages_vma+0xe1/0x290 do_wp_page+0x19f/0x840 handle_pte_fault+0x1cd/0x230 do_page_fault+0x1fd/0x4c0 page_fault+0x25/0x30 There are no memcgs created so there cannot be any in the soft limit excess obviously: [...] memory 0 1 1 so all this just seems to be mem_cgroup_largest_soft_limit_node trying to get spin_lock_irq(&mctz->lock) just to find out that the soft limit excess tree is empty. This is just pointless wasting of cycles and cache line bouncing during heavy parallel reclaim on large machines. The particular machine wasn't very healthy and most probably suffering from a memory leak which just caused the memory reclaim to trash heavily. But bouncing on the lock certainly didn't help... Fix this by optimistic lockless check and bail out early if the tree is empty. This is theoretically racy but that shouldn't matter all that much. First of all soft limit is a best effort feature and it is slowly getting deprecated and its usage should be really scarce. Bouncing on a lock without a good reason is surely much bigger problem, especially on large CPU machines. Link: http://lkml.kernel.org/r/1470073277-1056-1-git-send-email-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com> Acked-by: NVladimir Davydov <vdavydov@virtuozzo.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 29 7月, 2016 7 次提交
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由 Andy Lutomirski 提交于
We should account for stacks regardless of stack size, and we need to account in sub-page units if THREAD_SIZE < PAGE_SIZE. Change the units to kilobytes and Move it into account_kernel_stack(). Fixes: 12580e4b ("mm: memcontrol: report kernel stack usage in cgroup2 memory.stat") Link: http://lkml.kernel.org/r/9b5314e3ee5eda61b0317ec1563768602c1ef438.1468523549.git.luto@kernel.orgSigned-off-by: NAndy Lutomirski <luto@kernel.org> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Reviewed-by: NJosh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: NVladimir Davydov <vdavydov@virtuozzo.com> Acked-by: NMichal Hocko <mhocko@suse.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
Minchan Kim reported setting the following warning on a 32-bit system although it can affect 64-bit systems. WARNING: CPU: 4 PID: 1322 at mm/memcontrol.c:998 mem_cgroup_update_lru_size+0x103/0x110 mem_cgroup_update_lru_size(f44b4000, 1, -7): zid 1 lru_size 1 but empty Modules linked in: CPU: 4 PID: 1322 Comm: cp Not tainted 4.7.0-rc4-mm1+ #143 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x76/0xaf __warn+0xea/0x110 ? mem_cgroup_update_lru_size+0x103/0x110 warn_slowpath_fmt+0x3b/0x40 mem_cgroup_update_lru_size+0x103/0x110 isolate_lru_pages.isra.61+0x2e2/0x360 shrink_active_list+0xac/0x2a0 ? __delay+0xe/0x10 shrink_node_memcg+0x53c/0x7a0 shrink_node+0xab/0x2a0 do_try_to_free_pages+0xc6/0x390 try_to_free_pages+0x245/0x590 LRU list contents and counts are updated separately. Counts are updated before pages are added to the LRU and updated after pages are removed. The warning above is from a check in mem_cgroup_update_lru_size that ensures that list sizes of zero are empty. The problem is that node-lru needs to account for highmem pages if CONFIG_HIGHMEM is set. One impact of the implementation is that the sizes are updated in multiple passes when pages from multiple zones were isolated. This happens whether HIGHMEM is set or not. When multiple zones are isolated, it's possible for a debugging check in memcg to be tripped. This patch forces all the zone counts to be updated before the memcg function is called. Link: http://lkml.kernel.org/r/1468588165-12461-6-git-send-email-mgorman@techsingularity.netSigned-off-by: NMel Gorman <mgorman@techsingularity.net> Tested-by: NMinchan Kim <minchan@kernel.org> Reported-by: NMinchan Kim <minchan@kernel.org> Acked-by: NMinchan Kim <minchan@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
Memcg needs adjustment after moving LRUs to the node. Limits are tracked per memcg but the soft-limit excess is tracked per zone. As global page reclaim is based on the node, it is easy to imagine a situation where a zone soft limit is exceeded even though the memcg limit is fine. This patch moves the soft limit tree the node. Technically, all the variable names should also change but people are already familiar by the meaning of "mz" even if "mn" would be a more appropriate name now. Link: http://lkml.kernel.org/r/1467970510-21195-15-git-send-email-mgorman@techsingularity.netSigned-off-by: NMel Gorman <mgorman@techsingularity.net> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
Earlier patches focused on having direct reclaim and kswapd use data that is node-centric for reclaiming but shrink_node() itself still uses too much zone information. This patch removes unnecessary zone-based information with the most important decision being whether to continue reclaim or not. Some memcg APIs are adjusted as a result even though memcg itself still uses some zone information. [mgorman@techsingularity.net: optimization] Link: http://lkml.kernel.org/r/1468588165-12461-2-git-send-email-mgorman@techsingularity.net Link: http://lkml.kernel.org/r/1467970510-21195-14-git-send-email-mgorman@techsingularity.netSigned-off-by: NMel Gorman <mgorman@techsingularity.net> Acked-by: NMichal Hocko <mhocko@suse.com> Acked-by: NVlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
This moves the LRU lists from the zone to the node and related data such as counters, tracing, congestion tracking and writeback tracking. Unfortunately, due to reclaim and compaction retry logic, it is necessary to account for the number of LRU pages on both zone and node logic. Most reclaim logic is based on the node counters but the retry logic uses the zone counters which do not distinguish inactive and active sizes. It would be possible to leave the LRU counters on a per-zone basis but it's a heavier calculation across multiple cache lines that is much more frequent than the retry checks. Other than the LRU counters, this is mostly a mechanical patch but note that it introduces a number of anomalies. For example, the scans are per-zone but using per-node counters. We also mark a node as congested when a zone is congested. This causes weird problems that are fixed later but is easier to review. In the event that there is excessive overhead on 32-bit systems due to the nodes being on LRU then there are two potential solutions 1. Long-term isolation of highmem pages when reclaim is lowmem When pages are skipped, they are immediately added back onto the LRU list. If lowmem reclaim persisted for long periods of time, the same highmem pages get continually scanned. The idea would be that lowmem keeps those pages on a separate list until a reclaim for highmem pages arrives that splices the highmem pages back onto the LRU. It potentially could be implemented similar to the UNEVICTABLE list. That would reduce the skip rate with the potential corner case is that highmem pages have to be scanned and reclaimed to free lowmem slab pages. 2. Linear scan lowmem pages if the initial LRU shrink fails This will break LRU ordering but may be preferable and faster during memory pressure than skipping LRU pages. Link: http://lkml.kernel.org/r/1467970510-21195-4-git-send-email-mgorman@techsingularity.netSigned-off-by: NMel Gorman <mgorman@techsingularity.net> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NVlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
Node-based reclaim requires node-based LRUs and locking. This is a preparation patch that just moves the lru_lock to the node so later patches are easier to review. It is a mechanical change but note this patch makes contention worse because the LRU lock is hotter and direct reclaim and kswapd can contend on the same lock even when reclaiming from different zones. Link: http://lkml.kernel.org/r/1467970510-21195-3-git-send-email-mgorman@techsingularity.netSigned-off-by: NMel Gorman <mgorman@techsingularity.net> Reviewed-by: NMinchan Kim <minchan@kernel.org> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NVlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Weiner 提交于
Commit 23047a96 ("mm: workingset: per-cgroup cache thrash detection") added a page->mem_cgroup lookup to the cache eviction, refault, and activation paths, as well as locking to the activation path, and the vm-scalability tests showed a regression of -23%. While the test in question is an artificial worst-case scenario that doesn't occur in real workloads - reading two sparse files in parallel at full CPU speed just to hammer the LRU paths - there is still some optimizations that can be done in those paths. Inline the lookup functions to eliminate calls. Also, page->mem_cgroup doesn't need to be stabilized when counting an activation; we merely need to hold the RCU lock to prevent the memcg from being freed. This cuts down on overhead quite a bit: 23047a96 063f6715e77a7be5770d6081fe ---------------- -------------------------- %stddev %change %stddev \ | \ 21621405 +- 0% +11.3% 24069657 +- 2% vm-scalability.throughput [linux@roeck-us.net: drop unnecessary include file] [hannes@cmpxchg.org: add WARN_ON_ONCE()s] Link: http://lkml.kernel.org/r/20160707194024.GA26580@cmpxchg.org Link: http://lkml.kernel.org/r/20160624175101.GA3024@cmpxchg.orgReported-by: NYe Xiaolong <xiaolong.ye@intel.com> Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NMichal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: NGuenter Roeck <linux@roeck-us.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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