[PATCH] Module per-cpu alignment cannot always be met
authorRusty Russell <rusty@rustcorp.com.au>
Tue, 2 Aug 2005 04:11:47 +0000 (21:11 -0700)
committerLinus Torvalds <torvalds@g5.osdl.org>
Tue, 2 Aug 2005 04:38:01 +0000 (21:38 -0700)
commit842bbaaa7394820c8f1fe0629cd15478653caf86
tree5934040b40357f479b16d638ffd2fe435f4837e8
parent561fb765b97f287211a2c73a844c5edb12f44f1d
[PATCH] Module per-cpu alignment cannot always be met

The module code assumes noone will ever ask for a per-cpu area more than
SMP_CACHE_BYTES aligned.  However, as these cases show, gcc asks sometimes
asks for 32-byte alignment for the per-cpu section on a module, and if
CONFIG_X86_L1_CACHE_SHIFT is 4, we hit that BUG_ON().  This is obviously an
unusual combination, as there have been few reports, but better to warn
than die.

See:
http://www.ussg.iu.edu/hypermail/linux/kernel/0409.0/0768.html

And more recently:
http://bugs.gentoo.org/show_bug.cgi?id=97006

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
kernel/module.c