From d688abf50bd5a30d2c44dea2a72dd59052cd3cce Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Thu, 19 Jul 2007 01:49:17 -0700 Subject: [PATCH] move page writeback acounting out of macros page-writeback accounting is presently performed in the page-flags macros. This is inconsistent and a bit ugly and makes it awkward to implement per-backing_dev under-writeback page accounting. So move this accounting down to the callsite(s). Acked-by: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/page-flags.h | 38 ++++++++------------------------------ mm/page-writeback.c | 4 ++++ 2 files changed, 12 insertions(+), 30 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index a454176c3e30..209d3a47f50f 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -189,37 +189,15 @@ static inline void SetPageUptodate(struct page *page) #define __SetPagePrivate(page) __set_bit(PG_private, &(page)->flags) #define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags) +/* + * Only test-and-set exist for PG_writeback. The unconditional operators are + * risky: they bypass page accounting. + */ #define PageWriteback(page) test_bit(PG_writeback, &(page)->flags) -#define SetPageWriteback(page) \ - do { \ - if (!test_and_set_bit(PG_writeback, \ - &(page)->flags)) \ - inc_zone_page_state(page, NR_WRITEBACK); \ - } while (0) -#define TestSetPageWriteback(page) \ - ({ \ - int ret; \ - ret = test_and_set_bit(PG_writeback, \ - &(page)->flags); \ - if (!ret) \ - inc_zone_page_state(page, NR_WRITEBACK); \ - ret; \ - }) -#define ClearPageWriteback(page) \ - do { \ - if (test_and_clear_bit(PG_writeback, \ - &(page)->flags)) \ - dec_zone_page_state(page, NR_WRITEBACK); \ - } while (0) -#define TestClearPageWriteback(page) \ - ({ \ - int ret; \ - ret = test_and_clear_bit(PG_writeback, \ - &(page)->flags); \ - if (ret) \ - dec_zone_page_state(page, NR_WRITEBACK); \ - ret; \ - }) +#define TestSetPageWriteback(page) test_and_set_bit(PG_writeback, \ + &(page)->flags) +#define TestClearPageWriteback(page) test_and_clear_bit(PG_writeback, \ + &(page)->flags) #define PageBuddy(page) test_bit(PG_buddy, &(page)->flags) #define __SetPageBuddy(page) __set_bit(PG_buddy, &(page)->flags) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 51b3eb6ab445..63512a9ed57e 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -987,6 +987,8 @@ int test_clear_page_writeback(struct page *page) } else { ret = TestClearPageWriteback(page); } + if (ret) + dec_zone_page_state(page, NR_WRITEBACK); return ret; } @@ -1012,6 +1014,8 @@ int test_set_page_writeback(struct page *page) } else { ret = TestSetPageWriteback(page); } + if (!ret) + inc_zone_page_state(page, NR_WRITEBACK); return ret; } -- 2.30.2