From 6f26b2892bb561d713246311075235a4eef18634 Mon Sep 17 00:00:00 2001 From: Lukas Bulwahn Date: Mon, 14 Dec 2020 19:12:18 -0800 Subject: [PATCH] mm/vmscan: drop unneeded assignment in kswapd() The refactoring to kswapd() in commit c70935eb5c59 ("mm, vmscan: prevent kswapd sleeping prematurely due to mismatched classzone_idx") turned an assignment to reclaim_order into a dead store, as in all further paths, reclaim_order will be assigned again before it is used. make clang-analyzer on x86_64 tinyconfig caught my attention with: mm/vmscan.c: warning: Although the value stored to 'reclaim_order' is used in the enclosing expression, the value is never actually read from 'reclaim_order' [clang-analyzer-deadcode.DeadStores] Compilers will detect this unneeded assignment and optimize this anyway. So, the resulting binary is identical before and after this change. Simplify the code and remove unneeded assignment to make clang-analyzer happy. No functional change. No change in binary code. Link: https://lkml.kernel.org/r/20201004125827.17679-1-lukas.bulwahn@gmail.com Signed-off-by: Lukas Bulwahn Acked-by: Mel Gorman Cc: Vlastimil Babka Cc: Michal Hocko Cc: Nathan Chancellor Cc: Nick Desaulniers Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 0ec6321e98878..e71b563cda7ba 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3895,7 +3895,7 @@ kswapd_try_sleep: highest_zoneidx); /* Read the new order and highest_zoneidx */ - alloc_order = reclaim_order = READ_ONCE(pgdat->kswapd_order); + alloc_order = READ_ONCE(pgdat->kswapd_order); highest_zoneidx = kswapd_highest_zoneidx(pgdat, highest_zoneidx); WRITE_ONCE(pgdat->kswapd_order, 0); -- 2.39.5