diff options
| author | Kairui Song <kasong@tencent.com> | 2023-10-17 09:17:28 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-10-25 16:47:11 -0700 |
| commit | e5b306a082982cb98bc7ec48a382225522401a61 (patch) | |
| tree | e00b6ae62076aebb9089890881ef918f4e799a46 /mm/swap_state.c | |
| parent | e56808fef8f71a192b2740c0b6ea8be7ab865d54 (diff) | |
mm/swap: avoid a xa load for swapout path
A variable is never used for swapout path (shadowp is NULL) and compiler
is unable to optimize out the unneeded load since it's a function call.
The was introduced by 3852f6768ede ("mm/swapcache: support to handle the
shadow entries").
Link: https://lkml.kernel.org/r/20231017011728.37508-1-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/swap_state.c')
| -rw-r--r-- | mm/swap_state.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/swap_state.c b/mm/swap_state.c index b3b14bd0dd64..ab79ffb71736 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -109,9 +109,9 @@ int add_to_swap_cache(struct folio *folio, swp_entry_t entry, goto unlock; for (i = 0; i < nr; i++) { VM_BUG_ON_FOLIO(xas.xa_index != idx + i, folio); - old = xas_load(&xas); - if (xa_is_value(old)) { - if (shadowp) + if (shadowp) { + old = xas_load(&xas); + if (xa_is_value(old)) *shadowp = old; } xas_store(&xas, folio); |