Mel Gorman 1b4e3f26f9 mm: vmscan: Reduce throttling due to a failure to make progress ... Mike Galbraith, Alexey Avramov and Darrick Wong all reported similar problems due to reclaim throttling for excessive lengths of time. In Alexey's case, a memory hog that should go OOM quickly stalls for several minutes before stalling. In Mike and Darrick's cases, a small memcg environment stalled excessively even though the system had enough memory overall. Commit 69392a403f ("mm/vmscan: throttle reclaim when no progress is being made") introduced the problem although commit a19594ca4a ("mm/vmscan: increase the timeout if page reclaim is not making progress") made it worse. Systems at or near an OOM state that cannot be recovered must reach OOM quickly and memcg should kill tasks if a memcg is near OOM. To address this, only stall for the first zone in the zonelist, reduce the timeout to 1 tick for VMSCAN_THROTTLE_NOPROGRESS and only stall if the scan control nr_reclaimed is 0, kswapd is still active and there were excessive pages pending for writeback. If kswapd has stopped reclaiming due to excessive failures, do not stall at all so that OOM triggers relatively quickly. Similarly, if an LRU is simply congested, only lightly throttle similar to NOPROGRESS. Alexey's original case was the most straight forward for i in {1..3}; do tail /dev/zero; done On vanilla 5.16-rc1, this test stalled heavily, after the patch the test completes in a few seconds similar to 5.15. Alexey's second test case added watching a youtube video while tail runs 10 times. On 5.15, playback only jitters slightly, 5.16-rc1 stalls a lot with lots of frames missing and numerous audio glitches. With this patch applies, the video plays similarly to 5.15. [lkp@intel.com: Fix W=1 build warning] Link: https://lore.kernel.org/r/99e779783d6c7fce96448a3402061b9dc1b3b602.camel@gmx.de Link: https://lore.kernel.org/r/20211124011954.7cab9bb4@mail.inbox.lv Link: https://lore.kernel.org/r/20211022144651.19914-1-mgorman@techsingularity.net Link: https://lore.kernel.org/r/20211202150614.22440-1-mgorman@techsingularity.net Link: https://linux-regtracking.leemhuis.info/regzbot/regression/20211124011954.7cab9bb4@mail.inbox.lv/ Reported-and-tested-by: Alexey Avramov <hakavlad@inbox.lv> Reported-and-tested-by: Mike Galbraith <efault@gmx.de> Reported-and-tested-by: Darrick J. Wong <djwong@kernel.org> Reported-by: kernel test robot <lkp@intel.com> Acked-by: Hugh Dickins <hughd@google.com> Tracked-by: Thorsten Leemhuis <regressions@leemhuis.info> Fixes: 69392a403f ("mm/vmscan: throttle reclaim when no progress is being made") Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2021-12-31 11:17:07 -08:00
..
acpi	Merge branches 'acpica', 'acpi-ec', 'acpi-pmic' and 'acpi-video'	2021-11-10 14:03:14 +01:00
asm-generic	Add linux/cacheflush.h	2021-11-17 10:36:15 -05:00
clocksource	ARM:	2021-11-02 11:24:14 -07:00
crypto
drm	Removed the TTM Huge Page functionnality to address a crash, a timeout	2021-11-11 08:14:19 +10:00
dt-bindings	dt-bindings: Rename Ingenic CGU headers to ingenic,*.h	2021-11-11 22:27:14 -06:00
keys
kunit	include/kunit/test.h: replace kernel.h with the necessary inclusions	2021-11-09 10:02:49 -08:00
kvm
linux	mm: vmscan: Reduce throttling due to a failure to make progress	2021-12-31 11:17:07 -08:00
math-emu
media	Merge branch 'akpm' (patches from Andrew)	2021-11-09 10:11:53 -08:00
memory
misc
net	sctp: use call_rcu to free endpoint	2021-12-25 17:13:37 +00:00
pcmcia
ras
rdma	RDMA/netlink: Add __maybe_unused to static inline in C file	2021-11-16 13:13:08 -04:00
scsi	SCSI misc on 20211112	2021-11-12 12:25:50 -08:00
soc	net: mscc: ocelot: create a function that replaces an existing VCAP filter	2021-11-26 11:38:20 -08:00
sound	ASoC: Fixes for v5.16	2021-11-25 14:35:24 +01:00
target
trace	mm: vmscan: Reduce throttling due to a failure to make progress	2021-12-31 11:17:07 -08:00
uapi	Networking fixes for 5.16-rc8, including fixes from.. Santa?	2021-12-30 11:12:12 -08:00
vdso
video
xen	xen/console: harden hvc_xen against event channel storms	2021-12-16 08:24:08 +01:00