Bug in mm/thrash.c function grab_swap_token()
authorMika Kukkonen <mikukkon@miku.homelinux.net>
Fri, 11 May 2007 05:22:17 +0000 (22:22 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Fri, 11 May 2007 15:29:32 +0000 (08:29 -0700)
commit7faaa5f0bf4db6ac4908038e2139adc46c165ff4
treee6efe930b1749b4f133945468dad807c43fe1732
parent069f11f9d66bc582fb40a37a7b92363f5d321969
Bug in mm/thrash.c function grab_swap_token()

Following bug was uncovered by compiling with '-W' flag:

CC mm/thrash.o
mm/thrash.c: In function â\200\230grab_swap_tokenâ\200\231:
mm/thrash.c:52: warning: comparison of unsigned expression < 0 is always false

Variable token_priority is unsigned, so decrementing first and then
checking the result does not work; fixed by reversing the test, patch
attached (compile tested only).

I am not sure if likely() makes much sense in this new situation, but
I'll let somebody else to make a decision on that.

Signed-off-by: Mika Kukkonen <mikukkon@iki.fi>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/thrash.c