Messages in this thread Patch in this message |  | | From | Miaohe Lin <> | Subject | [PATCH 2/3] mm/zswap.c: avoid unnecessary copy-in at map time | Date | Sat, 22 May 2021 17:22:41 +0800 |
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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.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- mm/zswap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/zswap.c b/mm/zswap.c index e93459319fdb..c27ce9f2cdf8 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1203,7 +1203,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, 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); -- 2.23.0
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