From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: + =?US-ASCII?Q?mm-allow-swappiness-that-prefers-reclaiming-anon-over-the-f?= =?US-ASCII?Q?ile-workingset.patch?= added to -mm tree Date: Wed, 20 May 2020 20:31:49 -0700 Message-ID: <20200521033149.EqT3ATBEJ%akpm@linux-foundation.org> References: <20200513175005.1f4839360c18c0238df292d1@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Return-path: Received: from mail.kernel.org ([198.145.29.99]:34844 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727998AbgEUDbv (ORCPT ); Wed, 20 May 2020 23:31:51 -0400 In-Reply-To: <20200513175005.1f4839360c18c0238df292d1@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: hannes@cmpxchg.org, iamjoonsoo.kim@lge.com, mhocko@suse.com, minchan@kernel.org, mm-commits@vger.kernel.org, riel@redhat.com The patch titled Subject: mm: allow swappiness that prefers reclaiming anon over the file workingset has been added to the -mm tree. Its filename is mm-allow-swappiness-that-prefers-reclaiming-anon-over-the-file-workingset.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-allow-swappiness-that-prefers-reclaiming-anon-over-the-file-workingset.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-allow-swappiness-that-prefers-reclaiming-anon-over-the-file-workingset.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/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Johannes Weiner Subject: mm: allow swappiness that prefers reclaiming anon over the file workingset With the advent of fast random IO devices (SSDs, PMEM) and in-memory swap devices such as zswap, it's possible for swap to be much faster than filesystems, and for swapping to be preferable over thrashing filesystem caches. Allow setting swappiness - which defines the rough relative IO cost of cache misses between page cache and swap-backed pages - to reflect such situations by making the swap-preferred range configurable. Link: http://lkml.kernel.org/r/20200520232525.798933-4-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Cc: Joonsoo Kim Cc: Michal Hocko Cc: Minchan Kim Cc: Rik van Riel Signed-off-by: Andrew Morton --- Documentation/admin-guide/sysctl/vm.rst | 23 +++++++++++++++++----- kernel/sysctl.c | 3 +- mm/vmscan.c | 2 - 3 files changed, 21 insertions(+), 7 deletions(-) --- a/Documentation/admin-guide/sysctl/vm.rst~mm-allow-swappiness-that-prefers-reclaiming-anon-over-the-file-workingset +++ a/Documentation/admin-guide/sysctl/vm.rst @@ -831,14 +831,27 @@ tooling to work, you can do:: swappiness ========== -This control is used to define how aggressive the kernel will swap -memory pages. Higher values will increase aggressiveness, lower values -decrease the amount of swap. A value of 0 instructs the kernel not to -initiate swap until the amount of free and file-backed pages is less -than the high water mark in a zone. +This control is used to define the rough relative IO cost of swapping +and filesystem paging, as a value between 0 and 200. At 100, the VM +assumes equal IO cost and will thus apply memory pressure to the page +cache and swap-backed pages equally; lower values signify more +expensive swap IO, higher values indicates cheaper. + +Keep in mind that filesystem IO patterns under memory pressure tend to +be more efficient than swap's random IO. An optimal value will require +experimentation and will also be workload-dependent. The default value is 60. +For in-memory swap, like zram or zswap, as well as hybrid setups that +have swap on faster devices than the filesystem, values beyond 100 can +be considered. For example, if the random IO against the swap device +is on average 2x faster than IO from the filesystem, swappiness should +be 133 (x + 2x = 200, 2x = 133.33). + +At 0, the kernel will not initiate swap until the amount of free and +file-backed pages is less than the high watermark in a zone. + unprivileged_userfaultfd ======================== --- a/kernel/sysctl.c~mm-allow-swappiness-that-prefers-reclaiming-anon-over-the-file-workingset +++ a/kernel/sysctl.c @@ -131,6 +131,7 @@ static unsigned long zero_ul; static unsigned long one_ul = 1; static unsigned long long_max = LONG_MAX; static int one_hundred = 100; +static int two_hundred = 200; static int one_thousand = 1000; #ifdef CONFIG_PRINTK static int ten_thousand = 10000; @@ -1391,7 +1392,7 @@ static struct ctl_table vm_table[] = { .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = SYSCTL_ZERO, - .extra2 = &one_hundred, + .extra2 = &two_hundred, }, #ifdef CONFIG_HUGETLB_PAGE { --- a/mm/vmscan.c~mm-allow-swappiness-that-prefers-reclaiming-anon-over-the-file-workingset +++ a/mm/vmscan.c @@ -161,7 +161,7 @@ struct scan_control { #endif /* - * From 0 .. 100. Higher means more swappy. + * From 0 .. 200. Higher means more swappy. */ int vm_swappiness = 60; /* _ Patches currently in -mm which might be from hannes@cmpxchg.org are mm-fix-numa-node-file-count-error-in-replace_page_cache.patch mm-memcontrol-fix-stat-corrupting-race-in-charge-moving.patch mm-memcontrol-drop-compound-parameter-from-memcg-charging-api.patch mm-shmem-remove-rare-optimization-when-swapin-races-with-hole-punching.patch mm-memcontrol-move-out-cgroup-swaprate-throttling.patch mm-memcontrol-convert-page-cache-to-a-new-mem_cgroup_charge-api.patch mm-memcontrol-prepare-uncharging-for-removal-of-private-page-type-counters.patch mm-memcontrol-prepare-move_account-for-removal-of-private-page-type-counters.patch mm-memcontrol-prepare-cgroup-vmstat-infrastructure-for-native-anon-counters.patch mm-memcontrol-switch-to-native-nr_file_pages-and-nr_shmem-counters.patch mm-memcontrol-switch-to-native-nr_anon_mapped-counter.patch mm-memcontrol-switch-to-native-nr_anon_thps-counter.patch mm-memcontrol-switch-to-native-nr_anon_thps-counter-fix.patch mm-memcontrol-convert-anon-and-file-thp-to-new-mem_cgroup_charge-api.patch mm-memcontrol-convert-anon-and-file-thp-to-new-mem_cgroup_charge-api-fix.patch mm-memcontrol-drop-unused-try-commit-cancel-charge-api.patch mm-memcontrol-prepare-swap-controller-setup-for-integration.patch mm-memcontrol-make-swap-tracking-an-integral-part-of-memory-control.patch mm-memcontrol-charge-swapin-pages-on-instantiation.patch mm-memcontrol-delete-unused-lrucare-handling.patch mm-memcontrol-update-page-mem_cgroup-stability-rules.patch mm-fix-lru-balancing-effect-of-new-transparent-huge-pages.patch mm-keep-separate-anon-and-file-statistics-on-page-reclaim-activity.patch mm-allow-swappiness-that-prefers-reclaiming-anon-over-the-file-workingset.patch mm-fold-and-remove-lru_cache_add_anon-and-lru_cache_add_file.patch mm-workingset-let-cache-workingset-challenge-anon.patch mm-remove-use-once-cache-bias-from-lru-balancing.patch mm-vmscan-drop-unnecessary-div0-avoidance-rounding-in-get_scan_count.patch mm-base-lru-balancing-on-an-explicit-cost-model.patch mm-deactivations-shouldnt-bias-the-lru-balance.patch mm-only-count-actual-rotations-as-lru-reclaim-cost.patch mm-balance-lru-lists-based-on-relative-thrashing.patch mm-vmscan-determine-anon-file-pressure-balance-at-the-reclaim-root.patch mm-vmscan-reclaim-writepage-is-io-cost.patch mm-vmscan-limit-the-range-of-lru-type-balancing.patch