https://github.com/torvalds/linux
Revision 9282012fc0aa248b77a69f5eb802b67c5a16bb13 authored by Jaewon Kim on 25 July 2022, 09:52:12 UTC, committed by Andrew Morton on 29 July 2022, 18:33:37 UTC
There was a report that a task is waiting at the throttle_direct_reclaim. The pgscan_direct_throttle in vmstat was increasing. This is a bug where zone_watermark_fast returns true even when the free is very low. The commit f27ce0e14088 ("page_alloc: consider highatomic reserve in watermark fast") changed the watermark fast to consider highatomic reserve. But it did not handle a negative value case which can be happened when reserved_highatomic pageblock is bigger than the actual free. If watermark is considered as ok for the negative value, allocating contexts for order-0 will consume all free pages without direct reclaim, and finally free page may become depleted except highatomic free. Then allocating contexts may fall into throttle_direct_reclaim. This symptom may easily happen in a system where wmark min is low and other reclaimers like kswapd does not make free pages quickly. Handle the negative case by using MIN. Link: https://lkml.kernel.org/r/20220725095212.25388-1-jaewon31.kim@samsung.com Fixes: f27ce0e14088 ("page_alloc: consider highatomic reserve in watermark fast") Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> Reported-by: GyeongHwan Hong <gh21.hong@samsung.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Yong-Taek Lee <ytk.lee@samsung.com> Cc: <stable@vger.kerenl.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Tip revision: 9282012fc0aa248b77a69f5eb802b67c5a16bb13 authored by Jaewon Kim on 25 July 2022, 09:52:12 UTC
page_alloc: fix invalid watermark check on a negative value
page_alloc: fix invalid watermark check on a negative value
Tip revision: 9282012
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Makefile | -rw-r--r-- | 1.1 KB |
checks.c | -rw-r--r-- | 53.7 KB |
data.c | -rw-r--r-- | 4.5 KB |
dt_to_config | -rwxr-xr-x | 40.8 KB |
dtc-lexer.l | -rw-r--r-- | 6.1 KB |
dtc-parser.y | -rw-r--r-- | 10.6 KB |
dtc.c | -rw-r--r-- | 9.2 KB |
dtc.h | -rw-r--r-- | 9.6 KB |
dtx_diff | -rwxr-xr-x | 8.9 KB |
fdtget.c | -rw-r--r-- | 7.9 KB |
fdtoverlay.c | -rw-r--r-- | 4.2 KB |
fdtput.c | -rw-r--r-- | 7.7 KB |
flattree.c | -rw-r--r-- | 21.5 KB |
fstree.c | -rw-r--r-- | 1.5 KB |
livetree.c | -rw-r--r-- | 20.3 KB |
of_unittest_expect | -rwxr-xr-x | 9.4 KB |
srcpos.c | -rw-r--r-- | 8.6 KB |
srcpos.h | -rw-r--r-- | 2.9 KB |
treesource.c | -rw-r--r-- | 6.8 KB |
update-dtc-source.sh | -rwxr-xr-x | 2.5 KB |
util.c | -rw-r--r-- | 8.5 KB |
util.h | -rw-r--r-- | 7.0 KB |
version_gen.h | -rw-r--r-- | 42 bytes |
yamltree.c | -rw-r--r-- | 6.3 KB |
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