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| author | Christoph Lameter <clameter@sgi.com> | 2007-05-06 14:49:40 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-07 12:12:53 -0700 |
| commit | 6d7779538f765963ced45a3fa4bed7ba8d2c277d (patch) | |
| tree | 07d47e6ff1ab30309004e2ba0674dcabd83945c1 /lib/klist.c | |
| parent | d85f33855c303acfa87fa457157cef755b6087df (diff) | |
| download | talos-op-linux-6d7779538f765963ced45a3fa4bed7ba8d2c277d.tar.gz talos-op-linux-6d7779538f765963ced45a3fa4bed7ba8d2c277d.zip | |
mm: optimize compound_head() by avoiding a shared page flag
The patch adds PageTail(page) and PageHead(page) to check if a page is the
head or the tail of a compound page. This is done by masking the two bits
describing the state of a compound page and then comparing them. So one
comparision and a branch instead of two bit checks and two branches.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/klist.c')
0 files changed, 0 insertions, 0 deletions
