From eacde32757c7566d3aa760609585c78909532e40 Mon Sep 17 00:00:00 2001 From: Miaohe Lin Date: Thu, 19 May 2022 14:08:51 -0700 Subject: mm/swap: avoid calling swp_swap_info when try to check SWP_STABLE_WRITES Use flags of si directly to check SWP_STABLE_WRITES to avoid possible READ_ONCE and thus save some cpu cycles. [akpm@linux-foundation.org: use data_race() on si->flags, per Neil] Link: https://lkml.kernel.org/r/20220509131416.17553-10-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Cc: Alistair Popple Cc: David Hildenbrand Cc: David Howells Cc: Matthew Wilcox Cc: Naoya Horiguchi Cc: NeilBrown Cc: Peter Xu Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Oscar Salvador Signed-off-by: Andrew Morton --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/memory.c') diff --git a/mm/memory.c b/mm/memory.c index f4b2c05707b9..2bf5bca39567 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3889,7 +3889,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) */ exclusive = true; } else if (exclusive && PageWriteback(page) && - (swp_swap_info(entry)->flags & SWP_STABLE_WRITES)) { + data_race(si->flags & SWP_STABLE_WRITES)) { /* * This is tricky: not all swap backends support * concurrent page modifications while under writeback. -- cgit v1.2.3