Re: runtime regression with "x86/mm/pat: Emulate PAT when it is disabled"

[Toshi Kani <toshi.kani@hpe.com>]

On Mon, 2016-03-07 at 22:16 -0500, Paul Gortmaker wrote:
> [Re: runtime regression with "x86/mm/pat: Emulate PAT when it is
> disabled"] On 07/03/2016 (Mon 17:56) Toshi Kani wrote:
> 
> [..]
> 
> 
> > > > It may have seemed working before, but you did not have WC
> > > > configured
> > > > to PAT without calling pat_init().  There was not a proper check in
> > > > place to detect this error before.  Can you please check your code
> > > > to
> > > > see what caused this skip of pat_init()?  If you have a git tree, I
> > > > can
> > > > take a look as well. 
> > > 
> > > You already have git copies of what I'm running, since it is vanilla
> > > mainline commits.  No code changes at this end whatsoever.  I did the
> > > bisect on vanilla mainline.  All I took from yocto was their
> > > ".config"
> > > 
> > > To recap, v4.1-rc5-21-g9dac62909451 works,  v4.1-rc5-22-g9cd25aac1f44
> > > fails, and v4.5-rc6 also fails.  If pat_init() isn't called then this
> > > is a bug in current mainline.  I'll have a look later myself and see
> > > if I can trace out how we expect to get to pat_init() and how that
> > > might be skipped inadvertently unless someone beats me to it.
> > 
> > Oh, I see.  Can you send me the ".config" file?
> 
> I packaged the .config file for every bisect point in the original
> reproducer tarball.  Let me know if you can't find them.  It should
> look like this:
> 
> paul@dell760-paul:~/qemu-fail$ ls -al 00-configs/
> total 92
> drwxrwxr-x 23 paul paul 4096 Mar  3 10:59 .
> drwxrwxr-x  5 paul paul 4096 Mar  3 11:01 ..
> -rw-rw-r--  1 paul paul    0 Mar  3 10:59 00-all-dot-configs-are-in-here
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-1281-g43224b96af31
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-1625-g44d21c3f3a2e
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-3251-g4e241557fc1c
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-6547-g4570a37169d4
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-912-ge75c73ad6447
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-rc4-85-gd4688bdc6335
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-rc5-21-g9dac62909451
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-rc5-22-g9cd25aac1f44
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-rc5-23-g7202fdb1b329
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-rc5-27-gd838270e2516
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-rc5-35-g7ea402d01cb6
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-rc6-256-g9dda1658a9bd
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.1-rc6-296-g7ef3d7d58d9d
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.2
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.2-rc1
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.3
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.4
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.4.1
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.4.1-348-g0194c7658611
> drwxrwxr-x  2 paul paul 4096 Mar  3 10:59 v4.5-rc6
> paul@dell760-paul:~/qemu-fail$ 
> 
> Please check if they are present in the reproducer you downloaded.
> Maybe somehow I uploaded a version without the config files.

Yes, I have these directories, but I do not see anything under them...  Now
that I do not think there is anything unique in your .config file, but it'd
be still good to check.  Please send me .config file for v4.5-rc6 (if you
do not have it now, .config for other ver is OK as well).

$ ls -Rl
.:
total 84
-rw-rw-r--. 1 toshi toshi    0 Mar  3 08:59 00-all-dot-configs-are-in-here
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-1281-g43224b96af31
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-1625-g44d21c3f3a2e
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-3251-g4e241557fc1c
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-6547-g4570a37169d4
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-912-ge75c73ad6447
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-rc4-85-gd4688bdc6335
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-rc5-21-g9dac62909451
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-rc5-22-g9cd25aac1f44
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-rc5-23-g7202fdb1b329
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-rc5-27-gd838270e2516
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-rc5-35-g7ea402d01cb6
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-rc6-256-g9dda1658a9bd
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.1-rc6-296-g7ef3d7d58d9d
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.2
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.2-rc1
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.3
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.4
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.4.1
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.4.1-348-g0194c7658611
drwxrwxr-x. 2 toshi toshi 4096 Mar  3 08:59 v4.5-rc6

./v4.1:
total 0

./v4.1-1281-g43224b96af31:
total 0

./v4.1-1625-g44d21c3f3a2e:
total 0

./v4.1-3251-g4e241557fc1c:
total 0
./v4.1-6547-g4570a37169d4:
total 0

./v4.1-912-ge75c73ad6447:
total 0

./v4.1-rc4-85-gd4688bdc6335:
total 0

./v4.1-rc5-21-g9dac62909451:
total 0

./v4.1-rc5-22-g9cd25aac1f44:
total 0

./v4.1-rc5-23-g7202fdb1b329:
total 0

./v4.1-rc5-27-gd838270e2516:
total 0
./v4.1-rc5-35-g7ea402d01cb6:
total 0

./v4.1-rc6-256-g9dda1658a9bd:
total 0

./v4.1-rc6-296-g7ef3d7d58d9d:
total 0

./v4.2:
total 0

./v4.2-rc1:
total 0

./v4.3:
total 0

./v4.4:
total 0
./v4.4.1:
total 0

./v4.4.1-348-g0194c7658611:
total 0

./v4.5-rc6:
total 0

Thanks,
-Toshi