diff mbox

[RESEND,GIT,tj-percpu] percpu: fix spurious alignment WARN in legacy SMP percpu allocator

Message ID 49B75215.5010707@kernel.org (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Tejun Heo March 11, 2009, 5:54 a.m. UTC 
Impact: remove spurious WARN on legacy SMP percpu allocator

Commit f2a8205c4ef1af917d175c36a4097ae5587791c8 incorrectly added too
tight WARN_ON_ONCE() on alignments for UP and legacy SMP percpu
allocator.  Commit e317603694bfd17b28a40de9d65e1a4ec12f816e fixed it
for UP but legacy SMP allocator was forgotten.  Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Sachin P. Sant <sachinp@in.ibm.com>
---
(RESEND: cc'ing Ingo. :-)

Oops, that was a stupid omission.  This patch should fix it.  Ingo,
please pull from the following git vector to receive the first first
four patches from the use-dynamic-percpu-allocator-by-default patchset
(without the actual conversion which can disrupt archs) + this patch.
I moved the actual conversion patch into #tj-percpu-exp branch, so the
pull should be safe.

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git tj-percpu

Thanks.

 mm/allocpercpu.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

Comments

Sachin P. Sant March 11, 2009, 6:48 a.m. UTC | #1 
Tejun Heo wrote:
> Impact: remove spurious WARN on legacy SMP percpu allocator
>
> Commit f2a8205c4ef1af917d175c36a4097ae5587791c8 incorrectly added too
> tight WARN_ON_ONCE() on alignments for UP and legacy SMP percpu
> allocator.  Commit e317603694bfd17b28a40de9d65e1a4ec12f816e fixed it
> for UP but legacy SMP allocator was forgotten.  Fix it.
>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Reported-by: Sachin P. Sant <sachinp@in.ibm.com>
> ---
Thanks. The patch fixes the warning.

Tested-by : Sachin Sant <sachinp@in.ibm.com>
Ingo Molnar March 11, 2009, 9:31 a.m. UTC | #2 
* Tejun Heo <tj@kernel.org> wrote:

> Impact: remove spurious WARN on legacy SMP percpu allocator
> 
> Commit f2a8205c4ef1af917d175c36a4097ae5587791c8 incorrectly added too
> tight WARN_ON_ONCE() on alignments for UP and legacy SMP percpu
> allocator.  Commit e317603694bfd17b28a40de9d65e1a4ec12f816e fixed it
> for UP but legacy SMP allocator was forgotten.  Fix it.
> 
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Reported-by: Sachin P. Sant <sachinp@in.ibm.com>
> ---
> (RESEND: cc'ing Ingo. :-)
> 
> Oops, that was a stupid omission.  This patch should fix it.  Ingo,
> please pull from the following git vector to receive the first first
> four patches from the use-dynamic-percpu-allocator-by-default patchset
> (without the actual conversion which can disrupt archs) + this patch.
> I moved the actual conversion patch into #tj-percpu-exp branch, so the
> pull should be safe.
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git tj-percpu
> 
> Thanks.

Pulled into tip:core/percpu, thanks a lot Tejun!

	Ingo
diff mbox

Patch

diff --git a/mm/allocpercpu.c b/mm/allocpercpu.c
index 3653c57..1882923 100644
--- a/mm/allocpercpu.c
+++ b/mm/allocpercpu.c
@@ -120,7 +120,7 @@  void *__alloc_percpu(size_t size, size_t align)
 	 * on it.  Larger alignment should only be used for module
 	 * percpu sections on SMP for which this path isn't used.
 	 */
-	WARN_ON_ONCE(align > __alignof__(unsigned long long));
+	WARN_ON_ONCE(align > SMP_CACHE_BYTES);
 
 	if (unlikely(!pdata))
 		return NULL;