From 2b47a24cee0eedbb9b106ef3e992db0ddf48f740 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 e716f2eb24de ("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 0ec6321e9887..e71b563cda7b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3895,7 +3895,7 @@ static int kswapd(void *p) 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); -- GitLab