]> git.baikalelectronics.ru Git - kernel.git/commit
mm: workingset: restore refault tracking for single-page files
authorJohannes Weiner <hannes@cmpxchg.org>
Tue, 13 Dec 2016 00:43:55 +0000 (16:43 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 13 Dec 2016 02:55:08 +0000 (18:55 -0800)
commitc89d2ec0ce5f3f04ff2ff1463ec5c0bc23c04655
tree869be21f6babac4c47c9ee607004620ffb790f5e
parenta08afe440d7c64385a0192d46c476b7973b3e4cb
mm: workingset: restore refault tracking for single-page files

Shadow entries in the page cache used to be accounted behind the radix
tree implementation's back in the upper bits of node->count, and the
radix tree code extending a single-entry tree with a shadow entry in
root->rnode would corrupt that counter.  As a result, we could not put
shadow entries at index 0 if the tree didn't have any other entries, and
that means no refault detection for any single-page file.

Now that the shadow entries are tracked natively in the radix tree's
exceptional counter, this is no longer necessary.  Extending and
shrinking the tree from and to single entries in root->rnode now does
the right thing when the entry is exceptional, remove that limitation.

Link: http://lkml.kernel.org/r/20161117193244.GF23430@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/filemap.c