Re: [tip:x86/urgent] x86/mm/cpa: Convert noop to functional fix

[Andrea Arcangeli <aarcange@redhat.com>]

Hi,

On Thu, Apr 11, 2013 at 02:29:18PM +0200, Ingo Molnar wrote:
> 
> 
> * tip-bot for Andrea Arcangeli <tipbot@zytor.com> wrote:
> 
> > Commit-ID:  f76cfa3c2496c462b5bc01bd0c9340c2715b73ca
> > Gitweb:     http://git.kernel.org/tip/f76cfa3c2496c462b5bc01bd0c9340c2715b73ca
> > Author:     Andrea Arcangeli <aarcange@redhat.com>
> > AuthorDate: Wed, 10 Apr 2013 15:28:25 +0200
> > Committer:  Ingo Molnar <mingo@kernel.org>
> > CommitDate: Thu, 11 Apr 2013 10:34:42 +0200
> > 
> > x86/mm/cpa: Convert noop to functional fix
> 
> I think it's this commit that causes the following cpa-selftest failure:
> 
> CPA self-test:
> ffff880038000000 level 2 but not PSE 8000000038000062
> ffff880038200000 level 2 but not PSE 8000000038200062
> ffff880038400000 level 2 but not PSE 8000000038400062
> ffff880038600000 level 2 but not PSE 8000000038600062
> ffff880038800000 level 2 but not PSE 8000000038800062
> ffff880038a00000 level 2 but not PSE 8000000038a00062
> ffff880038c00000 level 2 but not PSE 8000000038c00062
> ffff880038e00000 level 2 but not PSE 8000000038e00062
> 
> ...
> 
>  4k 134128 large 250 gb 0 x 1[ffff88000009a000-ffff88000009a000] miss 0
> ------------[ cut here ]------------
> WARNING: at arch/x86/mm/pageattr-test.c:226 pageattr_test+0x3e1/0x410()
> NOT PASSED. Please report.
> Pid: 32, comm: pageattr-test Not tainted 3.9.0-rc6+ #222036
> Call Trace:
>  [<ffffffff8104fdd3>] warn_slowpath_common+0x62/0x7b
>  [<ffffffff8104fe5a>] warn_slowpath_fmt+0x46/0x48
>  [<ffffffff8102b3d9>] ? lookup_address+0xad/0x127
>  [<ffffffff8102c766>] pageattr_test+0x3e1/0x410
>  [<ffffffff8102c795>] ? pageattr_test+0x410/0x410
>  [<ffffffff8102c7af>] do_pageattr_test+0x1a/0x3d
>  [<ffffffff81070a8d>] kthread+0xa2/0xaa
>  [<ffffffff810709eb>] ? __kthread_parkme+0x65/0x65
>  [<ffffffff81aad73c>] ret_from_fork+0x7c/0xb0
>  [<ffffffff810709eb>] ? __kthread_parkme+0x65/0x65
> ---[ end trace 582fec3a45bb42b7 ]---
> device: 'vcs2': device_add

This looks a warning resulting from a false positive in the CPA self
test, not a bug in f76cfa3c2496c462b5bc01bd0c9340c2715b73ca. I'll send
a patch to correct it. I can't reproduce it here so it would be great
if you could test the fix on your system above to verify.

Thanks,
Andrea