The patch titled
Subject: swap-reduce-lock-contention-on-swap-cache-from-swap-slots-allocation-v4
has been added to the -mm tree. Its filename is
swap-reduce-lock-contention-on-swap-cache-from-swap-slots-allocation-v4.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/swap-reduce-lock-contention-on-swap-cache-from-swap-slots-allocation-v4.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/swap-reduce-lock-contention-on-swap-cache-from-swap-slots-allocation-v4.patch
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------------------------------------------------------
From: Huang Ying <ying.huang@xxxxxxxxx>
Subject: swap-reduce-lock-contention-on-swap-cache-from-swap-slots-allocation-v4
- Fix wrong ALIGN() usage with ALIGN_DOWN(). Thanks Daniel's comments!
- Add some comments. Thanks Daniel's comments!
Link: http://lkml.kernel.org/r/20200529010840.928819-1-ying.huang@xxxxxxxxx
Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Reviewed-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swapfile.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/mm/swapfile.c~swap-reduce-lock-contention-on-swap-cache-from-swap-slots-allocation-v4
+++ a/mm/swapfile.c
@@ -613,7 +613,8 @@ new_cluster:
} else if (!cluster_list_empty(&si->discard_clusters)) {
/*
* we don't have free cluster but have some clusters in
- * discarding, do discard now and reclaim them
+ * discarding, do discard now and reclaim them, then
+ * reread cluster_next_cpu since we dropped si->lock
*/
swap_do_scheduled_discard(si);
*scan_base = this_cpu_read(*si->cluster_next_cpu);
@@ -745,7 +746,7 @@ static void set_cluster_next(struct swap
return;
next = si->lowest_bit +
prandom_u32_max(si->highest_bit - si->lowest_bit + 1);
- next = ALIGN(next, SWAP_ADDRESS_SPACE_PAGES);
+ next = ALIGN_DOWN(next, SWAP_ADDRESS_SPACE_PAGES);
next = max_t(unsigned int, next, si->lowest_bit);
}
this_cpu_write(*si->cluster_next_cpu, next);
_
Patches currently in -mm which might be from ying.huang@xxxxxxxxx are
swap-try-to-scan-more-free-slots-even-when-fragmented.patch
mm-swap-use-prandom_u32_max.patch
swap-reduce-lock-contention-on-swap-cache-from-swap-slots-allocation.patch
swap-reduce-lock-contention-on-swap-cache-from-swap-slots-allocation-v3.patch
swap-reduce-lock-contention-on-swap-cache-from-swap-slots-allocation-v4.patch
proc-pid-smaps-add-pmd-migration-entry-parsing.patch
