The patch titled
Subject: mm/frontswap.c: use non-atomic '__set_bit()' when possible
has been added to the -mm tree. Its filename is
mm-mempool-use-non-atomic-__set_bit-when-possible.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-mempool-use-non-atomic-__set_bit-when-possible.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-mempool-use-non-atomic-__set_bit-when-possible.patch
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------------------------------------------------------
From: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Subject: mm/frontswap.c: use non-atomic '__set_bit()' when possible
the 'a' and 'b' bitmaps are local to this function, so no concurrent
access can occur. So the non-atomic '__set_bit()' can be used to save a
few cycles.
Link: https://lkml.kernel.org/r/e52476da5cee57151745c5c3c934a69798dc6fa4.1638132190.git.christophe.jaillet@xxxxxxxxxx
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/frontswap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/frontswap.c~mm-mempool-use-non-atomic-__set_bit-when-possible
+++ a/mm/frontswap.c
@@ -127,7 +127,7 @@ void frontswap_register_ops(struct front
spin_lock(&swap_lock);
plist_for_each_entry(si, &swap_active_head, list) {
if (!WARN_ON(!si->frontswap_map))
- set_bit(si->type, a);
+ __set_bit(si->type, a);
}
spin_unlock(&swap_lock);
@@ -149,7 +149,7 @@ void frontswap_register_ops(struct front
spin_lock(&swap_lock);
plist_for_each_entry(si, &swap_active_head, list) {
if (si->frontswap_map)
- set_bit(si->type, b);
+ __set_bit(si->type, b);
}
spin_unlock(&swap_lock);
_
Patches currently in -mm which might be from christophe.jaillet@xxxxxxxxxx are
mm-mempool-use-non-atomic-__set_bit-when-possible.patch
