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| author | Christoph Lameter | 2007-05-06 23:49:40 +0200 |
|---|---|---|
| committer | Linus Torvalds | 2007-05-07 21:12:53 +0200 |
| commit | 6d7779538f765963ced45a3fa4bed7ba8d2c277d (patch) | |
| tree | 07d47e6ff1ab30309004e2ba0674dcabd83945c1 /mm/slab.c | |
| parent | Make page->private usable in compound pages (diff) | |
| download | kernel-qcow2-linux-6d7779538f765963ced45a3fa4bed7ba8d2c277d.tar.gz kernel-qcow2-linux-6d7779538f765963ced45a3fa4bed7ba8d2c277d.tar.xz kernel-qcow2-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 'mm/slab.c')
0 files changed, 0 insertions, 0 deletions