diff options
| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2020-10-13 16:51:41 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-13 18:38:29 -0700 |
| commit | a8cf7f272b5a28a62ecfc39d6f7d75b4f486e350 (patch) | |
| tree | f87bdb5a32aa1647c5233f9dbca92ef90b81b287 /mm/filemap.c | |
| parent | 63ec1973ddf3eb70feb5728088ca190f1af449cb (diff) | |
mm: add find_lock_head
Add a new FGP_HEAD flag which avoids calling find_subpage() and add a
convenience wrapper for it.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Link: https://lkml.kernel.org/r/20200910183318.20139-9-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/filemap.c')
| -rw-r--r-- | mm/filemap.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index b44346a748fa..63d2fed539d7 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1737,6 +1737,8 @@ repeat: * * * %FGP_ACCESSED - The page will be marked accessed. * * %FGP_LOCK - The page is returned locked. + * * %FGP_HEAD - If the page is present and a THP, return the head page + * rather than the exact page specified by the index. * * %FGP_CREAT - If no page is present then a new page is allocated using * @gfp_mask and added to the page cache and the VM's LRU list. * The page is returned locked and with an increased refcount. @@ -1765,7 +1767,6 @@ repeat: page = NULL; if (!page) goto no_page; - page = find_subpage(page, index); if (fgp_flags & FGP_LOCK) { if (fgp_flags & FGP_NOWAIT) { @@ -1778,12 +1779,12 @@ repeat: } /* Has the page been truncated? */ - if (unlikely(compound_head(page)->mapping != mapping)) { + if (unlikely(page->mapping != mapping)) { unlock_page(page); put_page(page); goto repeat; } - VM_BUG_ON_PAGE(page->index != index, page); + VM_BUG_ON_PAGE(!thp_contains(page, index), page); } if (fgp_flags & FGP_ACCESSED) @@ -1793,6 +1794,8 @@ repeat: if (page_is_idle(page)) clear_page_idle(page); } + if (!(fgp_flags & FGP_HEAD)) + page = find_subpage(page, index); no_page: if (!page && (fgp_flags & FGP_CREAT)) { |