The patch titled
Subject: mm/zswap.c: avoid unnecessary copy-in at map time
has been removed from the -mm tree. Its filename was
mm-zswapc-avoid-unnecessary-copy-in-at-map-time.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Subject: mm/zswap.c: avoid unnecessary copy-in at map time
The buf mapped via zpool_map_handle() is only used to store compressed
page buffer and there is no information to extract from it. So we could
use ZPOOL_MM_WO instead to avoid unnecessary copy-in at map time.
Link: https://lkml.kernel.org/r/20210522092242.3233191-3-linmiaohe@xxxxxxxxxx
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Cc: Dan Streetman <ddstreet@xxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Seth Jennings <sjenning@xxxxxxxxxx>
Cc: Tian Tao <tiantao6@xxxxxxxxxxxxx>
Cc: Vitaly Wool <vitaly.wool@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/zswap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/zswap.c~mm-zswapc-avoid-unnecessary-copy-in-at-map-time
+++ a/mm/zswap.c
@@ -1203,7 +1203,7 @@ static int zswap_frontswap_store(unsigne
zswap_reject_alloc_fail++;
goto put_dstmem;
}
- buf = zpool_map_handle(entry->pool->zpool, handle, ZPOOL_MM_RW);
+ buf = zpool_map_handle(entry->pool->zpool, handle, ZPOOL_MM_WO);
memcpy(buf, &zhdr, hlen);
memcpy(buf + hlen, dst, dlen);
zpool_unmap_handle(entry->pool->zpool, handle);
_
Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are
mm-zsmallocc-combine-two-atomic-ops-in-zs_pool_dec_isolated.patch
