| commit | 6d7779538f765963ced45a3fa4bed7ba8d2c277d | [log] [tgz] |
|---|---|---|
| author | Christoph Lameter <clameter@sgi.com> | Sun May 06 14:49:40 2007 -0700 |
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | Mon May 07 12:12:53 2007 -0700 |
| tree | 07d47e6ff1ab30309004e2ba0674dcabd83945c1 | |
| parent | d85f33855c303acfa87fa457157cef755b6087df [diff] |
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>