From 8659dea64769b581d9f1f67fd3615b245359b46a Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 22 Oct 2015 09:03:32 +1100 Subject: [PATCH] page-flags: define behavior of FS/IO-related flags on compound pages MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit It seems we don't have compound page on FS/IO path currently. Use PF_NO_COMPOUND to catch if we have. The odd exception is PG_dirty: sound uses compound pages and maps them with PTEs. PF_NO_COMPOUND triggers VM_BUG_ON() in set_page_dirty() on handling shared fault. Let's use PF_HEAD for PG_dirty. Signed-off-by: Kirill A. Shutemov Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Dave Hansen Cc: Mel Gorman Cc: Rik van Riel Cc: Vlastimil Babka Cc: Christoph Lameter Cc: Naoya Horiguchi Cc: Steve Capper Cc: "Aneesh Kumar K.V" Cc: Johannes Weiner Cc: Michal Hocko Cc: Jerome Marchand Cc: Jérôme Glisse Signed-off-by: Andrew Morton --- include/linux/page-flags.h | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 32c87eb470cb..2493f80b949b 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -257,16 +257,16 @@ static inline int __TestClearPage##uname(struct page *page) { return 0; } TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) __PAGEFLAG(Locked, locked, PF_NO_TAIL) -PAGEFLAG(Error, error, PF_ANY) TESTCLEARFLAG(Error, error, PF_ANY) +PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND) PAGEFLAG(Referenced, referenced, PF_ANY) TESTCLEARFLAG(Referenced, referenced, PF_ANY) __SETPAGEFLAG(Referenced, referenced, PF_ANY) -PAGEFLAG(Dirty, dirty, PF_ANY) TESTSCFLAG(Dirty, dirty, PF_ANY) - __CLEARPAGEFLAG(Dirty, dirty, PF_ANY) +PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) + __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) PAGEFLAG(LRU, lru, PF_ANY) __CLEARPAGEFLAG(LRU, lru, PF_ANY) PAGEFLAG(Active, active, PF_ANY) __CLEARPAGEFLAG(Active, active, PF_ANY) TESTCLEARFLAG(Active, active, PF_ANY) __PAGEFLAG(Slab, slab, PF_ANY) -PAGEFLAG(Checked, checked, PF_ANY) /* Used by some filesystems */ +PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */ PAGEFLAG(Pinned, pinned, PF_ANY) TESTSCFLAG(Pinned, pinned, PF_ANY) /* Xen */ PAGEFLAG(SavePinned, savepinned, PF_ANY); /* Xen */ PAGEFLAG(Foreign, foreign, PF_ANY); /* Xen */ @@ -292,12 +292,15 @@ PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY) * Only test-and-set exist for PG_writeback. The unconditional operators are * risky: they bypass page accounting. */ -TESTPAGEFLAG(Writeback, writeback, PF_ANY) TESTSCFLAG(Writeback, writeback, PF_ANY) -PAGEFLAG(MappedToDisk, mappedtodisk, PF_ANY) +TESTPAGEFLAG(Writeback, writeback, PF_NO_COMPOUND) + TESTSCFLAG(Writeback, writeback, PF_NO_COMPOUND) +PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_COMPOUND) /* PG_readahead is only used for reads; PG_reclaim is only for writes */ -PAGEFLAG(Reclaim, reclaim, PF_ANY) TESTCLEARFLAG(Reclaim, reclaim, PF_ANY) -PAGEFLAG(Readahead, reclaim, PF_ANY) TESTCLEARFLAG(Readahead, reclaim, PF_ANY) +PAGEFLAG(Reclaim, reclaim, PF_NO_COMPOUND) + TESTCLEARFLAG(Reclaim, reclaim, PF_NO_COMPOUND) +PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND) + TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND) #ifdef CONFIG_HIGHMEM /* @@ -413,7 +416,7 @@ static inline int PageUptodate(struct page *page) static inline void __SetPageUptodate(struct page *page) { smp_wmb(); - __set_bit(PG_uptodate, &(page)->flags); + __set_bit(PG_uptodate, &page->flags); } static inline void SetPageUptodate(struct page *page) @@ -424,7 +427,7 @@ static inline void SetPageUptodate(struct page *page) * uptodate are actually visible before PageUptodate becomes true. */ smp_wmb(); - set_bit(PG_uptodate, &(page)->flags); + set_bit(PG_uptodate, &page->flags); } CLEARPAGEFLAG(Uptodate, uptodate, PF_ANY) -- 2.39.5