From 1c824a680b1b67ad43c0908f11a70bcf37af56d5 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 29 Apr 2021 22:55:32 -0700 Subject: mm: page-writeback: simplify memcg handling in test_clear_page_writeback() Page writeback doesn't hold a page reference, which allows truncate to free a page the second PageWriteback is cleared. This used to require special attention in test_clear_page_writeback(), where we had to be careful not to rely on the unstable page->memcg binding and look up all the necessary information before clearing the writeback flag. Since commit 073861ed77b6 ("mm: fix VM_BUG_ON(PageTail) and BUG_ON(PageWriteback)") test_clear_page_writeback() is called with an explicit reference on the page, and this dance is no longer needed. Use unlock_page_memcg() and dec_lruvec_page_state() directly. This removes the last user of the lock_page_memcg() return value, change it to void. Touch up the comments in there as well. This also removes the last extern user of __unlock_page_memcg(), make it static. Further, it removes the last user of dec_lruvec_state(), delete it, along with a few other unused helpers. Link: https://lkml.kernel.org/r/YCQbYAWg4nvBFL6h@cmpxchg.org Signed-off-by: Johannes Weiner Acked-by: Hugh Dickins Reviewed-by: Shakeel Butt Acked-by: Michal Hocko Cc: Roman Gushchin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/vmstat.h | 24 +++--------------------- 1 file changed, 3 insertions(+), 21 deletions(-) (limited to 'include/linux/vmstat.h') diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index 506d625163a1..3299cd69e4ca 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -512,16 +512,10 @@ static inline void mod_lruvec_page_state(struct page *page, #endif /* CONFIG_MEMCG */ -static inline void __inc_lruvec_state(struct lruvec *lruvec, - enum node_stat_item idx) -{ - __mod_lruvec_state(lruvec, idx, 1); -} - -static inline void __dec_lruvec_state(struct lruvec *lruvec, - enum node_stat_item idx) +static inline void inc_lruvec_state(struct lruvec *lruvec, + enum node_stat_item idx) { - __mod_lruvec_state(lruvec, idx, -1); + mod_lruvec_state(lruvec, idx, 1); } static inline void __inc_lruvec_page_state(struct page *page, @@ -536,18 +530,6 @@ static inline void __dec_lruvec_page_state(struct page *page, __mod_lruvec_page_state(page, idx, -1); } -static inline void inc_lruvec_state(struct lruvec *lruvec, - enum node_stat_item idx) -{ - mod_lruvec_state(lruvec, idx, 1); -} - -static inline void dec_lruvec_state(struct lruvec *lruvec, - enum node_stat_item idx) -{ - mod_lruvec_state(lruvec, idx, -1); -} - static inline void inc_lruvec_page_state(struct page *page, enum node_stat_item idx) { -- cgit v1.3-18-gd494