Bug 12417 - glx performance drop with: "x86: PAT: implement track/untrack of pfnmap regions for x86 - v3"
glx performance drop with: "x86: PAT: implement track/untrack of pfnmap regio...
Status: CLOSED CODE_FIX
Product: Platform Specific/Hardware
Classification: Unclassified
Component: x86-64
All Linux
: P1 normal
Assigned To: platform_x86_64@kernel-bugs.osdl.org
:
Depends on:
Blocks: 12398
  Show dependency treegraph
 
Reported: 2009-01-10 16:47 UTC by Rafael J. Wysocki
Modified: 2009-02-04 16:55 UTC (History)
2 users (show)

See Also:
Kernel Version: commit 5899329b19100c0b82dc78e9b21ed8b920c9ffb3
Tree: Mainline
Regression: Yes


Attachments

Description Rafael J. Wysocki 2009-01-10 16:47:55 UTC
Subject    : [regression] glx performance drop with: "x86: PAT: implement track/untrack of pfnmap regions for x86 - v3"
Submitter  : Alexey Fisher <bug-track@fisher-privat.net>
Date       : 2009-01-06 18:46
References : http://marc.info/?l=linux-kernel&m=123126782822696&w=4
Handled-By : "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>

This entry is being used for tracking a regression from 2.6.28.  Please don't
close it until the problem is fixed in the mainline.

Introduced by:

commit 5899329b19100c0b82dc78e9b21ed8b920c9ffb3
Author: venkatesh.pallipadi@intel.com <venkatesh.pallipadi@intel.com>
Date:   Thu Dec 18 11:41:30 2008 -0800

    x86: PAT: implement track/untrack of pfnmap regions for x86 - v3

    Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
    Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
    Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Comment 1 Rafael J. Wysocki 2009-01-10 16:48:19 UTC
First-Bad-Commit : 5899329b19100c0b82dc78e9b21ed8b920c9ffb3
Comment 2 Brian Rogers 2009-01-22 03:18:20 UTC
I just bisected a freeze back to this same commit. On my 64-bit laptop system, any kernel past this commit with PAT enabled will freeze when I VT switch from X to a console, leaving a mostly black image with a few scatterings of text.
Comment 3 Ingo Molnar 2009-01-22 04:02:37 UTC
> I just bisected a freeze back to this same commit. On my 64-bit laptop 
> system, any kernel past this commit with PAT enabled will freeze when I 
> VT switch from X to a console, leaving a mostly black image with a few 
> scatterings of text.

There are a handful of PAT bugs fixed in the -tip tree:

  http://people.redhat.com/mingo/tip.git/README

Could you please double-check whether your box gets fixed by them too?

	Ingo

Comment 4 Brian Rogers 2009-01-22 15:59:13 UTC
VT switching works on tip/master with PAT enabled. Appears to be solved.
Comment 5 Rafael J. Wysocki 2009-02-04 04:19:45 UTC
Handled-By : Ingo Molnar <mingo@elte.hu>
Comment 6 Rafael J. Wysocki 2009-02-04 16:54:30 UTC
On Wednesday 04 February 2009, Alexey Fisher wrote:
> Ingo Molnar schrieb:
> > * Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > 
> >> This message has been generated automatically as a part of a report
> >> of recent regressions.
> >>
> >> The following bug entry is on the current list of known regressions
> >> from 2.6.28.  Please verify if it still should be listed and let me know
> >> (either way).
> >>
> >>
> >> Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=12417
> >> Subject		: glx performance drop with: "x86: PAT: implement track/untrack of pfnmap regions for x86 - v3"
> >> Submitter	: Alexey Fisher <bug-track@fisher-privat.net>
> >> Date		: 2009-01-06 18:46 (30 days old)
> >> First-Bad-Commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=5899329b19100c0b82dc78e9b21ed8b920c9ffb3
> >> References	: http://marc.info/?l=linux-kernel&m=123126782822696&w=4
> >> Handled-By	: Pallipadi, Venkatesh <venkatesh.pallipadi@intel.com>
> >> 		  Ingo Molnar <mingo@elte.hu>
> >>
> > 
> > this should be fixed in latest -git. Alexey, can you confirm?
> > 
> > 	Ingo
> 
> I confirm it. It working  great with latest git 2.6.29-rc3-00495-gdcf6a79.
> 	Alexey


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