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2021-11-11mm: unexport {,un}lock_page_memcgChristoph Hellwig1-2/+0
These are only used in built-in core mm code. Link: https://lkml.kernel.org/r/20210820095815.445392-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-11mm: unexport folio_memcg_{,un}lockChristoph Hellwig1-2/+0
Patch series "unexport memcg locking helpers". Neither the old page-based nor the new folio-based memcg locking helpers are used in modular code at all, so drop the exports. This patch (of 2): folio_memcg_{,un}lock are only used in built-in core mm code. Link: https://lkml.kernel.org/r/20210820095815.445392-1-hch@lst.de Link: https://lkml.kernel.org/r/20210820095815.445392-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-125/+88
Merge misc updates from Andrew Morton: "257 patches. Subsystems affected by this patch series: scripts, ocfs2, vfs, and mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache, gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools, memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm, vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram, cleanups, kfence, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits) mm/damon: remove return value from before_terminate callback mm/damon: fix a few spelling mistakes in comments and a pr_debug message mm/damon: simplify stop mechanism Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions Docs/admin-guide/mm/damon/start: simplify the content Docs/admin-guide/mm/damon/start: fix a wrong link Docs/admin-guide/mm/damon/start: fix wrong example commands mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on mm/damon: remove unnecessary variable initialization Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM) selftests/damon: support watermarks mm/damon/dbgfs: support watermarks mm/damon/schemes: activate schemes based on a watermarks mechanism tools/selftests/damon: update for regions prioritization of schemes mm/damon/dbgfs: support prioritization weights mm/damon/vaddr,paddr: support pageout prioritization mm/damon/schemes: prioritize regions within the quotas mm/damon/selftests: support schemes quotas mm/damon/dbgfs: support quotas of schemes ...
2021-11-06mm/vmscan: throttle reclaim when no progress is being madeMel Gorman1-9/+1
Memcg reclaim throttles on congestion if no reclaim progress is made. This makes little sense, it might be due to writeback or a host of other factors. For !memcg reclaim, it's messy. Direct reclaim primarily is throttled in the page allocator if it is failing to make progress. Kswapd throttles if too many pages are under writeback and marked for immediate reclaim. This patch explicitly throttles if reclaim is failing to make progress. [vbabka@suse.cz: Remove redundant code] Link: https://lkml.kernel.org/r/20211022144651.19914-4-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Darrick J . Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: NeilBrown <neilb@suse.de> Cc: Rik van Riel <riel@surriel.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06memcg: prohibit unconditional exceeding the limit of dying tasksVasily Averin1-19/+8
Memory cgroup charging allows killed or exiting tasks to exceed the hard limit. It is assumed that the amount of the memory charged by those tasks is bound and most of the memory will get released while the task is exiting. This is resembling a heuristic for the global OOM situation when tasks get access to memory reserves. There is no global memory shortage at the memcg level so the memcg heuristic is more relieved. The above assumption is overly optimistic though. E.g. vmalloc can scale to really large requests and the heuristic would allow that. We used to have an early break in the vmalloc allocator for killed tasks but this has been reverted by commit b8c8a338f75e ("Revert "vmalloc: back off when the current task is killed""). There are likely other similar code paths which do not check for fatal signals in an allocation&charge loop. Also there are some kernel objects charged to a memcg which are not bound to a process life time. It has been observed that it is not really hard to trigger these bypasses and cause global OOM situation. One potential way to address these runaways would be to limit the amount of excess (similar to the global OOM with limited oom reserves). This is certainly possible but it is not really clear how much of an excess is desirable and still protects from global OOMs as that would have to consider the overall memcg configuration. This patch is addressing the problem by removing the heuristic altogether. Bypass is only allowed for requests which either cannot fail or where the failure is not desirable while excess should be still limited (e.g. atomic requests). Implementation wise a killed or dying task fails to charge if it has passed the OOM killer stage. That should give all forms of reclaim chance to restore the limit before the failure (ENOMEM) and tell the caller to back off. In addition, this patch renames should_force_charge() helper to task_is_dying() because now its use is not associated witch forced charging. This patch depends on pagefault_out_of_memory() to not trigger out_of_memory(), because then a memcg failure can unwind to VM_FAULT_OOM and cause a global OOM killer. Link: https://lkml.kernel.org/r/8f5cebbb-06da-4902-91f0-6566fc4b4203@virtuozzo.com Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Suggested-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Shakeel Butt <shakeelb@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06mm: memcontrol: remove the kmem statesMuchun Song1-5/+2
Now the kmem states is only used to indicate whether the kmem is offline. However, we can set ->kmemcg_id to -1 to indicate whether the kmem is offline. Finally, we can remove the kmem states to simplify the code. Link: https://lkml.kernel.org/r/20211025125259.56624-1-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06mm: memcontrol: remove kmemcg_id reparentingMuchun Song1-15/+4
Since slab objects and kmem pages are charged to object cgroup instead of memory cgroup, memcg_reparent_objcgs() will reparent this cgroup and all its descendants to its parent cgroup. This already makes further list_lru_add()'s add elements to the parent's list. So it is unnecessary to change kmemcg_id of an offline cgroup to its parent's id. It just wastes CPU cycles. Just remove the redundant code. Link: https://lkml.kernel.org/r/20211025125102.56533-1-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06memcg, kmem: further deprecate kmem.limit_in_bytesShakeel Butt1-34/+5
The deprecation process of kmem.limit_in_bytes started with the commit 0158115f702 ("memcg, kmem: deprecate kmem.limit_in_bytes") which also explains in detail the motivation behind the deprecation. To summarize, it is the unexpected behavior on hitting the kmem limit. This patch moves the deprecation process to the next stage by disallowing to set the kmem limit. In future we might just remove the kmem.limit_in_bytes file completely. [akpm@linux-foundation.org: s/ENOTSUPP/EOPNOTSUPP/] [arnd@arndb.de: mark cancel_charge() inline] Link: https://lkml.kernel.org/r/20211022070542.679839-1-arnd@kernel.org Link: https://lkml.kernel.org/r/20211019153408.2916808-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Vasily Averin <vvs@virtuozzo.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06mm/memcg: remove obsolete memcg_free_kmem()Waiman Long1-11/+3
Since commit d648bcc7fe65 ("mm: kmem: make memcg_kmem_enabled() irreversible"), the only thing memcg_free_kmem() does is to call memcg_offline_kmem() when the memcg is still online which can happen when online_css() fails due to -ENOMEM. However, the name memcg_free_kmem() is confusing and it is more clear and straight forward to call memcg_offline_kmem() directly from mem_cgroup_css_free(). Link: https://lkml.kernel.org/r/20211005202450.11775-1-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Suggested-by: Roman Gushchin <guro@fb.com> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06memcg: unify memcg stat flushingShakeel Butt1-9/+10
The memcg stats can be flushed in multiple context and potentially in parallel too. For example multiple parallel user space readers for memcg stats will contend on the rstat locks with each other. There is no need for that. We just need one flusher and everyone else can benefit. In addition after aa48e47e3906 ("memcg: infrastructure to flush memcg stats") the kernel periodically flush the memcg stats from the root, so, the other flushers will potentially have much less work to do. Link: https://lkml.kernel.org/r/20211001190040.48086-2-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Michal Koutný" <mkoutny@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06memcg: flush stats only if updatedShakeel Butt1-23/+55
At the moment, the kernel flushes the memcg stats on every refault and also on every reclaim iteration. Although rstat maintains per-cpu update tree but on the flush the kernel still has to go through all the cpu rstat update tree to check if there is anything to flush. This patch adds the tracking on the stats update side to make flush side more clever by skipping the flush if there is no update. The stats update codepath is very sensitive performance wise for many workloads and benchmarks. So, we can not follow what the commit aa48e47e3906 ("memcg: infrastructure to flush memcg stats") did which was triggering async flush through queue_work() and caused a lot performance regression reports. That got reverted by the commit 1f828223b799 ("memcg: flush lruvec stats in the refault"). In this patch we kept the stats update codepath very minimal and let the stats reader side to flush the stats only when the updates are over a specific threshold. For now the threshold is (nr_cpus * CHARGE_BATCH). To evaluate the impact of this patch, an 8 GiB tmpfs file is created on a system with swap-on-zram and the file was pushed to swap through memory.force_empty interface. On reading the whole file, the memcg stat flush in the refault code path is triggered. With this patch, we observed 63% reduction in the read time of 8 GiB file. Link: https://lkml.kernel.org/r/20211001190040.48086-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Reviewed-by: "Michal Koutný" <mkoutny@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06mm/memcg: drop swp_entry_t* in mc_handle_file_pte()Peter Xu1-2/+2
It is unused after the rework of commit f5df8635c5a3 ("mm: use find_get_incore_page in memcontrol"). Link: https://lkml.kernel.org/r/20210916193014.80129-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-27mm/memcg: Add folio_lruvec_lock() and similar functionsMatthew Wilcox (Oracle)1-28/+49
These are the folio equivalents of lock_page_lruvec() and similar functions. Also convert lruvec_memcg_debug() to take a folio. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Add folio_lruvec()Matthew Wilcox (Oracle)1-3/+6
This replaces mem_cgroup_page_lruvec(). All callers converted. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Convert mem_cgroup_move_account() to use a folioMatthew Wilcox (Oracle)1-18/+19
This saves dozens of bytes of text by eliminating a lot of calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Add folio_memcg_lock() and folio_memcg_unlock()Matthew Wilcox (Oracle)1-16/+29
These are the folio equivalents of lock_page_memcg() and unlock_page_memcg(). lock_page_memcg() and unlock_page_memcg() have too many callers to be easily replaced in a single patch, so reimplement them as wrappers for now to be cleaned up later when enough callers have been converted to use folios. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Convert mem_cgroup_track_foreign_dirty_slowpath() to folioMatthew Wilcox (Oracle)1-3/+3
The page was only being used for the memcg and to gather trace information, so this is a simple conversion. The only caller of mem_cgroup_track_foreign_dirty() will be converted to folios in a later patch, so doing this now makes that patch simpler. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Convert mem_cgroup_migrate() to take foliosMatthew Wilcox (Oracle)1-18/+17
Convert all callers of mem_cgroup_migrate() to call page_folio() first. They all look like they're using head pages already, but this proves it. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Convert mem_cgroup_uncharge() to take a folioMatthew Wilcox (Oracle)1-10/+4
Convert all the callers to call page_folio(). Most of them were already using a head page, but a few of them I can't prove were, so this may actually fix a bug. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Convert uncharge_page() to uncharge_folio()Matthew Wilcox (Oracle)1-16/+15
Use a folio rather than a page to ensure that we're only operating on base or head pages, and not tail pages. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Convert mem_cgroup_charge() to take a folioMatthew Wilcox (Oracle)1-21/+7
Convert all callers of mem_cgroup_charge() to call page_folio() on the page they're currently passing in. Many of them will be converted to use folios themselves soon. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Convert commit_charge() to take a folioMatthew Wilcox (Oracle)1-14/+13
The memcg_data is only set on the head page, so enforce that by typing it as a folio. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Add folio_memcg() and related functionsMatthew Wilcox (Oracle)1-9/+12
memcg information is only stored in the head page, so the memcg subsystem needs to assure that all accesses are to the head page. The first step is converting page_memcg() to folio_memcg(). The callers of page_memcg() and PageMemcgKmem() are not yet ready to be converted to use folios, so retain them as wrappers around folio_memcg() and folio_memcg_kmem(). They will be converted in a later patch set. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Convert memcg_check_events to take a node IDMatthew Wilcox (Oracle)1-11/+12
memcg_check_events only uses the page's nid, so call page_to_nid in the callers to make the interface easier to understand. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Remove soft_limit_tree_node()Matthew Wilcox (Oracle)1-9/+3
Opencode this one-line function in its three callers. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Use the node id in mem_cgroup_update_tree()Matthew Wilcox (Oracle)1-20/+4
By using the node id in mem_cgroup_update_tree(), we can delete soft_limit_tree_from_page() and mem_cgroup_page_nodeinfo(). Saves 42 bytes of kernel text on my config. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Remove 'page' parameter to mem_cgroup_charge_statistics()Matthew Wilcox (Oracle)1-6/+5
The last use of 'page' was removed by commit 468c398233da ("mm: memcontrol: switch to native NR_ANON_THPS counter"), so we can now remove the parameter from the function. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-23memcg: flush lruvec stats in the refaultShakeel Butt1-10/+0
Prior to the commit 7e1c0d6f5820 ("memcg: switch lruvec stats to rstat") and the commit aa48e47e3906 ("memcg: infrastructure to flush memcg stats"), each lruvec memcg stats can be off by (nr_cgroups * nr_cpus * 32) at worst and for unbounded amount of time. The commit aa48e47e3906 moved the lruvec stats to rstat infrastructure and the commit 7e1c0d6f5820 bounded the error for all the lruvec stats to (nr_cpus * 32) at worst for at most 2 seconds. More specifically it decoupled the number of stats and the number of cgroups from the error rate. However this reduction in error comes with the cost of triggering the slowpath of stats update more frequently. Previously in the slowpath the kernel adds the stats up the memcg tree. After aa48e47e3906, the kernel triggers the asyn lruvec stats flush through queue_work(). This causes regression reports from 0day kernel bot [1] as well as from phoronix test suite [2]. We tried two options to fix the regression: 1) Increase the threshold to trigger the slowpath in lruvec stats update codepath from 32 to 512. 2) Remove the slowpath from lruvec stats update codepath and instead flush the stats in the page refault codepath. The assumption is that the kernel timely flush the stats, so, the update tree would be small in the refault codepath to not cause the preformance impact. Following are the results of will-it-scale/page_fault[1|2|3] benchmark on four settings i.e. (1) 5.15-rc1 as baseline (2) 5.15-rc1 with aa48e47e3906 and 7e1c0d6f5820 reverted (3) 5.15-rc1 with option-1 (4) 5.15-rc1 with option-2. test (1) (2) (3) (4) pg_f1 368563 406277 (10.23%) 399693 (8.44%) 416398 (12.97%) pg_f2 338399 372133 (9.96%) 369180 (9.09%) 381024 (12.59%) pg_f3 500853 575399 (14.88%) 570388 (13.88%) 576083 (15.02%) From the above result, it seems like the option-2 not only solves the regression but also improves the performance for at least these benchmarks. Feng Tang (intel) ran the aim7 benchmark with these two options and confirms that option-1 reduces the regression but option-2 removes the regression. Michael Larabel (phoronix) ran multiple benchmarks with these options and reported the results at [3] and it shows for most benchmarks option-2 removes the regression introduced by the commit aa48e47e3906 ("memcg: infrastructure to flush memcg stats"). Based on the experiment results, this patch proposed the option-2 as the solution to resolve the regression. Link: https://lore.kernel.org/all/20210726022421.GB21872@xsang-OptiPlex-9020 [1] Link: https://www.phoronix.com/scan.php?page=article&item=linux515-compile-regress [2] Link: https://openbenchmarking.org/result/2109226-DEBU-LINUX5104 [3] Fixes: aa48e47e3906 ("memcg: infrastructure to flush memcg stats") Signed-off-by: Shakeel Butt <shakeelb@google.com> Tested-by: Michael Larabel <Michael@phoronix.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Roman Gushchin <guro@fb.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Hillf Danton <hdanton@sina.com>, Cc: Michal Koutný <mkoutny@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org>, Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-127/+101
Merge misc updates from Andrew Morton: "173 patches. Subsystems affected by this series: ia64, ocfs2, block, and mm (debug, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock, oom-kill, migration, ksm, percpu, vmstat, and madvise)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits) mm/madvise: add MADV_WILLNEED to process_madvise() mm/vmstat: remove unneeded return value mm/vmstat: simplify the array size calculation mm/vmstat: correct some wrong comments mm/percpu,c: remove obsolete comments of pcpu_chunk_populated() selftests: vm: add COW time test for KSM pages selftests: vm: add KSM merging time test mm: KSM: fix data type selftests: vm: add KSM merging across nodes test selftests: vm: add KSM zero page merging test selftests: vm: add KSM unmerge test selftests: vm: add KSM merge test mm/migrate: correct kernel-doc notation mm: wire up syscall process_mrelease mm: introduce process_mrelease system call memblock: make memblock_find_in_range method private mm/mempolicy.c: use in_task() in mempolicy_slab_node() mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies mm/mempolicy: advertise new MPOL_PREFERRED_MANY mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY ...
2021-09-03mm/vmpressure: replace vmpressure_to_css() with vmpressure_to_memcg()Hui Su1-2/+2
We can get memcg directly form vmpr instead of vmpr->memcg->css->memcg, so add a new func helper vmpressure_to_memcg(). And no code will use vmpressure_to_css(), so delete it. Link: https://lkml.kernel.org/r/20210630112146.455103-1-suhui@zeku.com Signed-off-by: Hui Su <suhui@zeku.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Chris Down <chris@chrisdown.name> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03memcg: make memcg->event_list_lock irqsafeShakeel Butt1-4/+4
The memcg->event_list_lock is usually taken in the normal context but when the userspace closes the corresponding eventfd, eventfd_release through memcg_event_wake takes memcg->event_list_lock with interrupts disabled. This is not an issue on its own but it creates a nested dependency from eventfd_ctx->wqh.lock to memcg->event_list_lock. Independently, for unrelated eventfd, eventfd_signal() can be called in the irq context, thus making eventfd_ctx->wqh.lock an irq lock. For example, FPGA DFL driver, VHOST VPDA driver and couple of VFIO drivers. This will force memcg->event_list_lock to be an irqsafe lock as well. One way to break the nested dependency between eventfd_ctx->wqh.lock and memcg->event_list_lock is to add an indirection. However the simplest solution would be to make memcg->event_list_lock irqsafe. This is cgroup v1 feature, is in maintenance and may get deprecated in near future. So, no need to add more code. BTW this has been discussed previously [1] but there weren't irq users of eventfd_signal() at the time. [1] https://www.spinics.net/lists/cgroups/msg06248.html Link: https://lkml.kernel.org/r/20210830172953.207257-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03memcg: fix up drain_local_stock commentMichal Hocko1-2/+3
Thomas and Vlastimil have noticed that the comment in drain_local_stock doesn't quite make sense. It talks about a synchronization with the memory hotplug but there is no actual memory hotplug involvement here. I meant to talk about cpu hotplug here. Fix that up and hopefuly make the comment more helpful by referencing the cpu hotplug callback as well. Link: https://lkml.kernel.org/r/YRDwOhVglJmY7ES5@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03mm, memcg: save some atomic ops when flush is already trueMiaohe Lin1-1/+1
Add 'else' to save some atomic ops in obj_stock_flush_required() when flush is already true. No functional change intended here. Link: https://lkml.kernel.org/r/20210807082835.61281-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Alex Shi <alexs@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03mm: memcontrol: set the correct memcg swappiness restrictionBaolin Wang1-1/+1
Since commit c843966c556d ("mm: allow swappiness that prefers reclaiming anon over the file workingset") has expended the swappiness value to make swap to be preferred in some systems. We should also change the memcg swappiness restriction to allow memcg swap-preferred. Link: https://lkml.kernel.org/r/d77469b90c45c49953ccbc51e54a1d465bc18f70.1627626255.git.baolin.wang@linux.alibaba.com Fixes: c843966c556d ("mm: allow swappiness that prefers reclaiming anon over the file workingset") Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03memcg: replace in_interrupt() by !in_task() in active_memcg()Vasily Averin1-1/+1
set_active_memcg() uses in_interrupt() check to select proper storage for cgroup: pointer on task struct or per-cpu pointer. It isn't fully correct: obsoleted in_interrupt() includes tasks with disabled BH. It's better to use '!in_task()' instead. Link: https://lkml.org/lkml/2021/7/26/487 Link: https://lkml.kernel.org/r/ed4448b0-4970-616f-7368-ef9dd3cb628d@virtuozzo.com Fixes: 37d5985c003d ("mm: kmem: prepare remote memcg charging infra for interrupt contexts") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03memcg: infrastructure to flush memcg statsShakeel Butt1-0/+34
At the moment memcg stats are read in four contexts: 1. memcg stat user interfaces 2. dirty throttling 3. page fault 4. memory reclaim Currently the kernel flushes the stats for first two cases. Flushing the stats for remaining two casese may have performance impact. Always flushing the memcg stats on the page fault code path may negatively impacts the performance of the applications. In addition flushing in the memory reclaim code path, though treated as slowpath, can become the source of contention for the global lock taken for stat flushing because when system or memcg is under memory pressure, many tasks may enter the reclaim path. This patch uses following mechanisms to solve these challenges: 1. Periodically flush the stats from root memcg every 2 seconds. This will time limit the out of sync stats. 2. Asynchronously flush the stats after fixed number of stat updates. In the worst case the stat can be out of sync by O(nr_cpus * BATCH) for 2 seconds. 3. For avoiding thundering herd to flush the stats particularly from the memory reclaim context, introduce memcg local spinlock and let only one flusher active at a time. This could have been done through cgroup_rstat_lock lock but that lock is used by other subsystem and for userspace reading memcg stats. So, it is better to keep flushers introduced by this patch decoupled from cgroup_rstat_lock. However we would have to use irqsafe version of rstat flush but that is fine as this code path will be flushing for whole tree and do the work for everyone. No one will be waiting for that worker. [shakeelb@google.com: fix sleep-in-wrong context bug] Link: https://lkml.kernel.org/r/20210716212137.1391164-2-shakeelb@google.com Link: https://lkml.kernel.org/r/20210714013948.270662-2-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Roman Gushchin <guro@fb.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03memcg: switch lruvec stats to rstatShakeel Butt1-76/+38
The commit 2d146aa3aa84 ("mm: memcontrol: switch to rstat") switched memcg stats to rstat infrastructure but skipped the conversion of the lruvec stats as such stats are read in the performance critical code paths and flushing stats may have impacted the performances of the applications. This patch converts the lruvec stats to rstat and later patches add mechanisms to keep the performance impact to minimum. The rstat conversion comes with the price i.e. memory cost. Effectively this patch reverts the savings done by the commit f3344adf38bd ("mm: memcontrol: optimize per-lruvec stats counter memory usage"). However this cost is justified due to negative impact of the inaccurate lruvec stats on many heuristics. One such case is reported in [1]. The memory reclaim code is filled with plethora of heuristics and many of those heuristics reads the lruvec stats. So, inaccurate stats can make such heuristics ineffective. [1] reports the impact of inaccurate lruvec stats on the "cache trim mode" heuristic. Inaccurate lruvec stats can impact the deactivation and aging anon heuristics as well. [1] https://lore.kernel.org/linux-mm/20210311004449.1170308-1-ying.huang@intel.com/ Link: https://lkml.kernel.org/r/20210716212137.1391164-1-shakeelb@google.com Link: https://lkml.kernel.org/r/20210714013948.270662-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Michal Koutný <mkoutny@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03mm, memcg: inline swap-related functions to improve disabled memcg configSuren Baghdasaryan1-10/+4
Inline mem_cgroup_try_charge_swap, mem_cgroup_uncharge_swap and cgroup_throttle_swaprate functions to perform mem_cgroup_disabled static key check inline before calling the main body of the function. This minimizes the memcg overhead in the pagefault and exit_mmap paths when memcgs are disabled using cgroup_disable=memory command-line option. This change results in ~1% overhead reduction when running PFT test [1] comparing {CONFIG_MEMCG=n} against {CONFIG_MEMCG=y, cgroup_disable=memory} configuration on an 8-core ARM64 Android device. [1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite Link: https://lkml.kernel.org/r/20210713010934.299876-3-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Alex Shi <alexs@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03mm, memcg: inline mem_cgroup_{charge/uncharge} to improve disabled memcg configSuren Baghdasaryan1-21/+12
Inline mem_cgroup_{charge/uncharge} and mem_cgroup_uncharge_list functions functions to perform mem_cgroup_disabled static key check inline before calling the main body of the function. This minimizes the memcg overhead in the pagefault and exit_mmap paths when memcgs are disabled using cgroup_disable=memory command-line option. This change results in ~0.4% overhead reduction when running PFT test [1] comparing {CONFIG_MEMCG=n} against {CONFIG_MEMCG=y, cgroup_disable=memory} configuration on an 8-core ARM64 Android device. [1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite Link: https://lkml.kernel.org/r/20210713010934.299876-2-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Alex Shi <alexs@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: Tejun Heo <tj@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03mm, memcg: add mem_cgroup_disabled checks in vmpressure and swap-related ↵Suren Baghdasaryan1-0/+3
functions Add mem_cgroup_disabled check in vmpressure, mem_cgroup_uncharge_swap and cgroup_throttle_swaprate functions. This minimizes the memcg overhead in the pagefault and exit_mmap paths when memcgs are disabled using cgroup_disable=memory command-line option. This change results in ~2.1% overhead reduction when running PFT test [1] comparing {CONFIG_MEMCG=n, CONFIG_MEMCG_SWAP=n} against {CONFIG_MEMCG=y, CONFIG_MEMCG_SWAP=y, cgroup_disable=memory} configuration on an 8-core ARM64 Android device. [1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite Link: https://lkml.kernel.org/r/20210713010934.299876-1-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alex Shi <alexs@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: Tejun Heo <tj@kernel.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03writeback: memcg: simplify cgroup_writeback_by_idShakeel Butt1-12/+1
Currently cgroup_writeback_by_id calls mem_cgroup_wb_stats() to get dirty pages for a memcg. However mem_cgroup_wb_stats() does a lot more than just get the number of dirty pages. Just directly get the number of dirty pages instead of calling mem_cgroup_wb_stats(). Also cgroup_writeback_by_id() is only called for best-effort dirty flushing, so remove the unused 'nr' parameter and no need to explicitly flush memcg stats. Link: https://lkml.kernel.org/r/20210722182627.2267368-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-2/+4
drivers/ptp/Kconfig: 55c8fca1dae1 ("ptp_pch: Restore dependency on PCI") e5f31552674e ("ethernet: fix PTP_1588_CLOCK dependencies") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-18net-memcg: pass in gfp_t mask to mem_cgroup_charge_skmem()Wei Wang1-13/+11
Add gfp_t mask as an input parameter to mem_cgroup_charge_skmem(), to give more control to the networking stack and enable it to change memcg charging behavior. In the future, the networking stack may decide to avoid oom-kills when fallbacks are more appropriate. One behavior change in mem_cgroup_charge_skmem() by this patch is to avoid force charging by default and let the caller decide when and if force charging is needed through the presence or absence of __GFP_NOFAIL. Signed-off-by: Wei Wang <weiwan@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-13mm/memcg: fix incorrect flushing of lruvec data in obj_stockWaiman Long1-2/+4
When mod_objcg_state() is called with a pgdat that is different from that in the obj_stock, the old lruvec data cached in obj_stock are flushed out. Unfortunately, they were flushed to the new pgdat and so the data go to the wrong node. This will screw up the slab data reported in /sys/devices/system/node/node*/meminfo. Fix that by flushing the data to the cached pgdat instead. Link: https://lkml.kernel.org/r/20210802143834.30578-1-longman@redhat.com Fixes: 68ac5b3c8db2 ("mm/memcg: cache vmstat data in percpu memcg_stock_pcp") Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Tejun Heo <tj@kernel.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> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: Chris Down <chris@chrisdown.name> Cc: Yafang Shao <laoar.shao@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-1/+2
Conflicting commits, all resolutions pretty trivial: drivers/bus/mhi/pci_generic.c 5c2c85315948 ("bus: mhi: pci-generic: configurable network interface MRU") 56f6f4c4eb2a ("bus: mhi: pci_generic: Apply no-op for wake using sideband wake boolean") drivers/nfc/s3fwrn5/firmware.c a0302ff5906a ("nfc: s3fwrn5: remove unnecessary label") 46573e3ab08f ("nfc: s3fwrn5: fix undefined parameter values in dev_err()") 801e541c79bb ("nfc: s3fwrn5: fix undefined parameter values in dev_err()") MAINTAINERS 7d901a1e878a ("net: phy: add Maxlinear GPY115/21x/24x driver") 8a7b46fa7902 ("MAINTAINERS: add Yasushi SHOJI as reviewer for the Microchip CAN BUS Analyzer Tool driver") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-30mm: memcontrol: fix blocking rstat function called from atomic cgroup1 ↵Johannes Weiner1-1/+2
thresholding code Dan Carpenter reports: The patch 2d146aa3aa84: "mm: memcontrol: switch to rstat" from Apr 29, 2021, leads to the following static checker warning: kernel/cgroup/rstat.c:200 cgroup_rstat_flush() warn: sleeping in atomic context mm/memcontrol.c 3572 static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) 3573 { 3574 unsigned long val; 3575 3576 if (mem_cgroup_is_root(memcg)) { 3577 cgroup_rstat_flush(memcg->css.cgroup); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This is from static analysis and potentially a false positive. The problem is that mem_cgroup_usage() is called from __mem_cgroup_threshold() which holds an rcu_read_lock(). And the cgroup_rstat_flush() function can sleep. 3578 val = memcg_page_state(memcg, NR_FILE_PAGES) + 3579 memcg_page_state(memcg, NR_ANON_MAPPED); 3580 if (swap) 3581 val += memcg_page_state(memcg, MEMCG_SWAP); 3582 } else { 3583 if (!swap) 3584 val = page_counter_read(&memcg->memory); 3585 else 3586 val = page_counter_read(&memcg->memsw); 3587 } 3588 return val; 3589 } __mem_cgroup_threshold() indeed holds the rcu lock. In addition, the thresholding code is invoked during stat changes, and those contexts have irqs disabled as well. If the lock breaking occurs inside the flush function, it will result in a sleep from an atomic context. Use the irqsafe flushing variant in mem_cgroup_usage() to fix this. Link: https://lkml.kernel.org/r/20210726150019.251820-1-hannes@cmpxchg.org Fixes: 2d146aa3aa84 ("mm: memcontrol: switch to rstat") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Chris Down <chris@chrisdown.name> Reviewed-by: Rik van Riel <riel@surriel.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-20memcg: enable accounting for IP address and routing-related objectsVasily Averin1-1/+1
An netadmin inside container can use 'ip a a' and 'ip r a' to assign a large number of ipv4/ipv6 addresses and routing entries and force kernel to allocate megabytes of unaccounted memory for long-lived per-netdevice related kernel objects: 'struct in_ifaddr', 'struct inet6_ifaddr', 'struct fib6_node', 'struct rt6_info', 'struct fib_rules' and ip_fib caches. These objects can be manually removed, though usually they lives in memory till destroy of its net namespace. It makes sense to account for them to restrict the host's memory consumption from inside the memcg-limited container. One of such objects is the 'struct fib6_node' mostly allocated in net/ipv6/route.c::__ip6_ins_rt() inside the lock_bh()/unlock_bh() section: write_lock_bh(&table->tb6_lock); err = fib6_add(&table->tb6_root, rt, info, mxc); write_unlock_bh(&table->tb6_lock); In this case it is not enough to simply add SLAB_ACCOUNT to corresponding kmem cache. The proper memory cgroup still cannot be found due to the incorrect 'in_interrupt()' check used in memcg_kmem_bypass(). Obsoleted in_interrupt() does not describe real execution context properly. >From include/linux/preempt.h: The following macros are deprecated and should not be used in new code: in_interrupt() - We're in NMI,IRQ,SoftIRQ context or have BH disabled To verify the current execution context new macro should be used instead: in_task() - We're in task context Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-02Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-2/+2
Merge more updates from Andrew Morton: "190 patches. Subsystems affected by this patch series: mm (hugetlb, userfaultfd, vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock, migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap, zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc, core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs, signals, exec, kcov, selftests, compress/decompress, and ipc" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits) ipc/util.c: use binary search for max_idx ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock ipc: use kmalloc for msg_queue and shmid_kernel ipc sem: use kvmalloc for sem_undo allocation lib/decompressors: remove set but not used variabled 'level' selftests/vm/pkeys: exercise x86 XSAVE init state selftests/vm/pkeys: refill shadow register after implicit kernel write selftests/vm/pkeys: handle negative sys_pkey_alloc() return code selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random kcov: add __no_sanitize_coverage to fix noinstr for all architectures exec: remove checks in __register_bimfmt() x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned hfsplus: report create_date to kstat.btime hfsplus: remove unnecessary oom message nilfs2: remove redundant continue statement in a while-loop kprobes: remove duplicated strong free_insn_page in x86 and s390 init: print out unknown kernel parameters checkpatch: do not complain about positive return values starting with EPOLL checkpatch: improve the indented label test checkpatch: scripts/spdxcheck.py now requires python3 ...
2021-07-01Merge branch 'for-5.14' of ↵Linus Torvalds1-3/+8
git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu Pull percpu updates from Dennis Zhou: - percpu chunk depopulation - depopulate backing pages for chunks with empty pages when we exceed a global threshold without those pages. This lets us reclaim a portion of memory that would previously be lost until the full chunk would be freed (possibly never). - memcg accounting cleanup - previously separate chunks were managed for normal allocations and __GFP_ACCOUNT allocations. These are now consolidated which cleans up the code quite a bit. - a few misc clean ups for clang warnings * 'for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu: percpu: optimize locking in pcpu_balance_workfn() percpu: initialize best_upa variable percpu: rework memcg accounting mm, memcg: introduce mem_cgroup_kmem_disabled() mm, memcg: mark cgroup_memory_nosocket, nokmem and noswap as __ro_after_init percpu: make symbol 'pcpu_free_slot' static percpu: implement partial chunk depopulation percpu: use pcpu_free_slot instead of pcpu_nr_slots - 1 percpu: factor out pcpu_check_block_hint() percpu: split __pcpu_balance_workfn() percpu: fix a comment about the chunks ordering
2021-07-01mm: remove special swap entry functionsAlistair Popple1-1/+1
Patch series "Add support for SVM atomics in Nouveau", v11. Introduction ============ Some devices have features such as atomic PTE bits that can be used to implement atomic access to system memory. To support atomic operations to a shared virtual memory page such a device needs access to that page which is exclusive of the CPU. This series introduces a mechanism to temporarily unmap pages granting exclusive access to a device. These changes are required to support OpenCL atomic operations in Nouveau to shared virtual memory (SVM) regions allocated with the CL_MEM_SVM_ATOMICS clSVMAlloc flag. A more complete description of the OpenCL SVM feature is available at https://www.khronos.org/registry/OpenCL/specs/3.0-unified/html/ OpenCL_API.html#_shared_virtual_memory . Implementation ============== Exclusive device access is implemented by adding a new swap entry type (SWAP_DEVICE_EXCLUSIVE) which is similar to a migration entry. The main difference is that on fault the original entry is immediately restored by the fault handler instead of waiting. Restoring the entry triggers calls to MMU notifers which allows a device driver to revoke the atomic access permission from the GPU prior to the CPU finalising the entry. Patches ======= Patches 1 & 2 refactor existing migration and device private entry functions. Patches 3 & 4 rework try_to_unmap_one() by splitting out unrelated functionality into separate functions - try_to_migrate_one() and try_to_munlock_one(). Patch 5 renames some existing code but does not introduce functionality. Patch 6 is a small clean-up to swap entry handling in copy_pte_range(). Patch 7 contains the bulk of the implementation for device exclusive memory. Patch 8 contains some additions to the HMM selftests to ensure everything works as expected. Patch 9 is a cleanup for the Nouveau SVM implementation. Patch 10 contains the implementation of atomic access for the Nouveau driver. Testing ======= This has been tested with upstream Mesa 21.1.0 and a simple OpenCL program which checks that GPU atomic accesses to system memory are atomic. Without this series the test fails as there is no way of write-protecting the page mapping which results in the device clobbering CPU writes. For reference the test is available at https://ozlabs.org/~apopple/opencl_svm_atomics/ Further testing has been performed by adding support for testing exclusive access to the hmm-tests kselftests. This patch (of 10): Remove multiple similar inline functions for dealing with different types of special swap entries. Both migration and device private swap entries use the swap offset to store a pfn. Instead of multiple inline functions to obtain a struct page for each swap entry type use a common function pfn_swap_entry_to_page(). Also open-code the various entry_to_pfn() functions as this results is shorter code that is easier to understand. Link: https://lkml.kernel.org/r/20210616105937.23201-1-apopple@nvidia.com Link: https://lkml.kernel.org/r/20210616105937.23201-2-apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>