The patch titled Subject: doc: describe memcg swappiness more precisely has been added to the -mm tree. Its filename is memcg-oom-fix-totalpages-calculation-for-memoryswappiness==0-fix.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Michal Hocko <mhocko@xxxxxxx> Subject: doc: describe memcg swappiness more precisely since fe35004f (mm: avoid swapping out with swappiness==0) memcg reclaim stopped swapping out anon pages completely when 0 value is used. Although this is somehow expected it hasn't been done for a really long time this way and so it is probably better to be explicit about the effect. Moreover global reclaim swapps out even when swappiness is 0 to prevent from OOM killer. Signed-off-by: Michal Hocko <mhocko@xxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/cgroups/memory.txt | 4 ++++ 1 file changed, 4 insertions(+) diff -puN Documentation/cgroups/memory.txt~memcg-oom-fix-totalpages-calculation-for-memoryswappiness==0-fix Documentation/cgroups/memory.txt --- a/Documentation/cgroups/memory.txt~memcg-oom-fix-totalpages-calculation-for-memoryswappiness==0-fix +++ a/Documentation/cgroups/memory.txt @@ -530,6 +530,10 @@ Note: 5.3 swappiness Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only. +Please note that unlike the global swappiness, memcg knob set to 0 +really prevents from any swapping even if there is a swap storage +available. This might lead to memcg OOM killer if there are no file +pages to reclaim. Following cgroups' swappiness can't be changed. - root cgroup (uses /proc/sys/vm/swappiness). _ Patches currently in -mm which might be from mhocko@xxxxxxx are linux-next.patch mm-fix-a-regression-with-highmem-introduced-by-changeset-7f1290f2f2a4d.patch thp-clean-up-__collapse_huge_page_isolate.patch thp-clean-up-__collapse_huge_page_isolate-v2.patch mm-introduce-mm_find_pmd.patch mm-introduce-mm_find_pmd-fix.patch thp-introduce-hugepage_vma_check.patch thp-cleanup-introduce-mk_huge_pmd.patch memory-hotplug-allocate-zones-pcp-before-onlining-pages-fix.patch memcg-make-it-possible-to-use-the-stock-for-more-than-one-page.patch memcg-reclaim-when-more-than-one-page-needed.patch memcg-change-defines-to-an-enum.patch memcg-kmem-accounting-basic-infrastructure.patch mm-add-a-__gfp_kmemcg-flag.patch memcg-kmem-controller-infrastructure.patch mm-allocate-kernel-pages-to-the-right-memcg.patch res_counter-return-amount-of-charges-after-res_counter_uncharge.patch memcg-kmem-accounting-lifecycle-management.patch memcg-use-static-branches-when-code-not-in-use.patch memcg-allow-a-memcg-with-kmem-charges-to-be-destructed.patch memcg-execute-the-whole-memcg-freeing-in-free_worker.patch fork-protect-architectures-where-thread_size-=-page_size-against-fork-bombs.patch memcg-add-documentation-about-the-kmem-controller.patch slab-slub-struct-memcg_params.patch slab-annotate-on-slab-caches-nodelist-locks.patch slab-slub-consider-a-memcg-parameter-in-kmem_create_cache.patch memcg-allocate-memory-for-memcg-caches-whenever-a-new-memcg-appears.patch memcg-infrastructure-to-match-an-allocation-to-the-right-cache.patch memcg-skip-memcg-kmem-allocations-in-specified-code-regions.patch slb-always-get-the-cache-from-its-page-in-kmem_cache_free.patch slb-allocate-objects-from-memcg-cache.patch memcg-destroy-memcg-caches.patch memcg-slb-track-all-the-memcg-children-of-a-kmem_cache.patch memcg-slb-shrink-dead-caches.patch memcg-aggregate-memcg-cache-values-in-slabinfo.patch slab-propagate-tunable-values.patch slub-slub-specific-propagation-changes.patch slub-slub-specific-propagation-changes-fix.patch kmem-add-slab-specific-documentation-about-the-kmem-controller.patch memcg-oom-fix-totalpages-calculation-for-memoryswappiness==0.patch memcg-oom-fix-totalpages-calculation-for-memoryswappiness==0-fix.patch drop_caches-add-some-documentation-and-info-messsge.patch drop_caches-add-some-documentation-and-info-messsge-checkpatch-fixes.patch mm-memblock-reduce-overhead-in-binary-search.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html