Re: [Bug 10328] New: [regression] performance drop for glx

Andrew Morton
2008-03-25T22:29:22Z

(switched to email. Please respond via emailed reply-to-all, not via the
bugzilla web interface).

On Tue, 25 Mar 2008 15:11:15 -0700 (PDT)
bugme-daemon@bugzilla.kernel.org wrote:

> http://bugzilla.kernel.org/show_bug.cgi?id=10328
>
> Summary: [regression] performance drop for glx
> Product: Memory Management
> Version: 2.5
> KernelVersion: 2.6.25-rc6
> Platform: All
> OS/Version: Linux
> Tree: Mainline
> Status: NEW
> Severity: normal
> Priority: P1
> Component: Other
> AssignedTo: akpm@osdl.org
> ReportedBy: bug-track@fisher-privat.net
>
>
> after commit 4138cc3418f5eaa7524ff8e927102863f1ba0ea5 i expirience some grafik
> related perfomance issues.
>
> I used glxgears for test.
> before this patch: 1281.005 FPS
> and after: 765.000 FPS

It nearly halved.

> latest tested commit a4083c9271e0a697278e089f2c0b9a95363ada0a
> still hase bad performance.
>
> I use Pentium D with 2GB RAM, Grafick: i945G, ICH7
>

That's

: commit 4138cc3418f5eaa7524ff8e927102863f1ba0ea5
: Author: Siddha, Suresh B <suresh.b.siddha@intel.com>
: Date: Wed Jan 30 13:33:43 2008 +0100
:
: x86: set strong uncacheable where UC is really desired
:
: Also use _PAGE_PWT for all the mappings which need uncache mapping.
: Instead of existing PAT2 which is UC- (and can be overwritten by MTRRs),
: we now use PAT3 which is strong uncacheable.
:
: This makes it consistent with pgprot_noncached()
:
: Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
: Signed-off-by: Ingo Molnar <mingo@elte.hu>
: Signed-off-by: Thomas Gleixner <tglx@linutronix.de>