Re: i915.ko WC writes are slow after ea8596bb2d8d379

* Chris Wilson wrote: > > > A bisection pointed to > > > > > > commit ea8596bb2d8d37957f3e92db9511c50801689180 > > > Author: Masami Hiramatsu > > > Date: Thu Jul 18 20:47:53 2013 +0900 > > > > > > kprobes/x86: Remove unused text_poke_smp() and text_poke_smp_batch() > > > functions >

Re: i915.ko WC writes are slow after ea8596bb2d8d379

* Andy Lutomirski wrote: > On Wed, Nov 18, 2015 at 6:48 AM, Chris Wilson > wrote: > > Although > > > > diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h > > index d2abbdb..ff4f029 100644 > > --- a/include/linux/stop_machine.h > > +++ b/include/linux/stop_machine.h > >

Re: i915.ko WC writes are slow after ea8596bb2d8d379

* Andy Lutomirski wrote: > On Wed, Nov 18, 2015 at 6:48 AM, Chris Wilson > wrote: > > Although > > > > diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h > > index d2abbdb..ff4f029 100644 > > ---

Re: i915.ko WC writes are slow after ea8596bb2d8d379

* Chris Wilson wrote: > > > A bisection pointed to > > > > > > commit ea8596bb2d8d37957f3e92db9511c50801689180 > > > Author: Masami Hiramatsu > > > Date: Thu Jul 18 20:47:53 2013 +0900 > > > > > > kprobes/x86: Remove unused

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Wed, Nov 18, 2015 at 6:48 AM, Chris Wilson wrote: > Although > > diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h > index d2abbdb..ff4f029 100644 > --- a/include/linux/stop_machine.h > +++ b/include/linux/stop_machine.h > @@ -97,7 +97,7 @@ static inline int

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Wed, Oct 08, 2014 at 05:10:59AM -0500, Chuck Ebbert wrote: > On Wed, 8 Oct 2014 10:03:36 +0100 > Chris Wilson wrote: > > > > > I ran into a problem on a Sandybridge i5-2500s whilst measuring the > > performance of GTT write-combining access. I found subsequent runs were > > about 10-40x

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Wed, Nov 18, 2015 at 6:48 AM, Chris Wilson wrote: > Although > > diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h > index d2abbdb..ff4f029 100644 > --- a/include/linux/stop_machine.h > +++ b/include/linux/stop_machine.h > @@ -97,7 +97,7 @@

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Wed, Oct 08, 2014 at 05:10:59AM -0500, Chuck Ebbert wrote: > On Wed, 8 Oct 2014 10:03:36 +0100 > Chris Wilson wrote: > > > > > I ran into a problem on a Sandybridge i5-2500s whilst measuring the > > performance of GTT write-combining access. I found subsequent runs

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Thu, Oct 09, 2014 at 09:46:37AM -0500, Chuck Ebbert wrote: > Well they're all the same. > > Hmm, x86info is not dumping all the variable MTRRs. You have 10, but > it only prints the first 8. I don't know if it will show anything > different, but can you try fixing it with this patch? Source

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Thu, 9 Oct 2014 14:00:47 +0100 Chris Wilson wrote: > On Thu, Oct 09, 2014 at 07:44:16AM -0500, Chuck Ebbert wrote: > > Could you try installing x86info and running "x86info --mtrr > > --all-cpus" while running the broken kernel? > > # /opt/xorg/src/intel-gpu-tools/tests/gem_gtt_speed >

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Thu, Oct 09, 2014 at 07:44:16AM -0500, Chuck Ebbert wrote: > Could you try installing x86info and running "x86info --mtrr > --all-cpus" while running the broken kernel? # /opt/xorg/src/intel-gpu-tools/tests/gem_gtt_speed IGT-Version: 1.8-g32a0308 (x86_64) (Linux: 3.17.0+ x86_64) Time to read

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Thu, 9 Oct 2014 07:53:31 +0100 Chris Wilson wrote: > # cat /proc/mtrr > reg00: base=0x0 (0MB), size= 2048MB, count=1: write-back > reg01: base=0x08000 ( 2048MB), size= 256MB, count=1: write-back > reg02: base=0x08e00 ( 2272MB), size= 32MB, count=1: uncachable > reg03:

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Wed, Oct 08, 2014 at 02:36:49PM -0700, H. Peter Anvin wrote: > On 10/08/2014 12:49 PM, Chris Wilson wrote: > > > > Indeed, this appears to be the explanation. (And here I thought PAT > > superseded mtrrs - i915.ko stopped trying to use assign an mtrr for its > > GTT quite a while ago.) > > >

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Wed, Oct 08, 2014 at 02:36:49PM -0700, H. Peter Anvin wrote: On 10/08/2014 12:49 PM, Chris Wilson wrote: Indeed, this appears to be the explanation. (And here I thought PAT superseded mtrrs - i915.ko stopped trying to use assign an mtrr for its GTT quite a while ago.) Replacing

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Thu, 9 Oct 2014 07:53:31 +0100 Chris Wilson ch...@chris-wilson.co.uk wrote: # cat /proc/mtrr reg00: base=0x0 (0MB), size= 2048MB, count=1: write-back reg01: base=0x08000 ( 2048MB), size= 256MB, count=1: write-back reg02: base=0x08e00 ( 2272MB), size= 32MB, count=1:

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Thu, Oct 09, 2014 at 07:44:16AM -0500, Chuck Ebbert wrote: Could you try installing x86info and running x86info --mtrr --all-cpus while running the broken kernel? # /opt/xorg/src/intel-gpu-tools/tests/gem_gtt_speed IGT-Version: 1.8-g32a0308 (x86_64) (Linux: 3.17.0+ x86_64) Time to read 16k

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Thu, 9 Oct 2014 14:00:47 +0100 Chris Wilson ch...@chris-wilson.co.uk wrote: On Thu, Oct 09, 2014 at 07:44:16AM -0500, Chuck Ebbert wrote: Could you try installing x86info and running x86info --mtrr --all-cpus while running the broken kernel? #

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Thu, Oct 09, 2014 at 09:46:37AM -0500, Chuck Ebbert wrote: Well they're all the same. Hmm, x86info is not dumping all the variable MTRRs. You have 10, but it only prints the first 8. I don't know if it will show anything different, but can you try fixing it with this patch? Source

Re: i915.ko WC writes are slow after ea8596bb2d8d379

(2014/10/09 2:47), Chuck Ebbert wrote: > On Wed, 8 Oct 2014 10:03:36 +0100 > Chris Wilson wrote: > >> and adding that back into the current build, e.g. >> >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >> index 3632743..48a8a69 100644 >> --- a/arch/x86/Kconfig >> +++ b/arch/x86/Kconfig >>

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On 10/08/2014 12:49 PM, Chris Wilson wrote: > > Indeed, this appears to be the explanation. (And here I thought PAT > superseded mtrrs - i915.ko stopped trying to use assign an mtrr for its > GTT quite a while ago.) > > Replacing the stop_machine there with on_each_cpu does the trick: > It

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Wed, Oct 08, 2014 at 05:10:59AM -0500, Chuck Ebbert wrote: > On Wed, 8 Oct 2014 10:03:36 +0100 > Chris Wilson wrote: > > > > > I ran into a problem on a Sandybridge i5-2500s whilst measuring the > > performance of GTT write-combining access. I found subsequent runs were > > about 10-40x

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Wed, 8 Oct 2014 10:03:36 +0100 Chris Wilson wrote: > and adding that back into the current build, e.g. > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 3632743..48a8a69 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -87,6 +87,7 @@ config X86 > select

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Wed, 8 Oct 2014 10:03:36 +0100 Chris Wilson wrote: > > I ran into a problem on a Sandybridge i5-2500s whilst measuring the > performance of GTT write-combining access. I found subsequent runs were > about 10-40x slower than the first. For example, > > igt/gem_gtt_speed: > > Time to read

i915.ko WC writes are slow after ea8596bb2d8d379

I ran into a problem on a Sandybridge i5-2500s whilst measuring the performance of GTT write-combining access. I found subsequent runs were about 10-40x slower than the first. For example, igt/gem_gtt_speed: Time to read 16k through a GTT map: 325.285µs Time to write 16k through a

i915.ko WC writes are slow after ea8596bb2d8d379

I ran into a problem on a Sandybridge i5-2500s whilst measuring the performance of GTT write-combining access. I found subsequent runs were about 10-40x slower than the first. For example, igt/gem_gtt_speed: Time to read 16k through a GTT map: 325.285µs Time to write 16k through a

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Wed, 8 Oct 2014 10:03:36 +0100 Chris Wilson ch...@chris-wilson.co.uk wrote: I ran into a problem on a Sandybridge i5-2500s whilst measuring the performance of GTT write-combining access. I found subsequent runs were about 10-40x slower than the first. For example, igt/gem_gtt_speed:

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Wed, 8 Oct 2014 10:03:36 +0100 Chris Wilson ch...@chris-wilson.co.uk wrote: and adding that back into the current build, e.g. diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 3632743..48a8a69 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -87,6 +87,7 @@ config X86

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On Wed, Oct 08, 2014 at 05:10:59AM -0500, Chuck Ebbert wrote: On Wed, 8 Oct 2014 10:03:36 +0100 Chris Wilson ch...@chris-wilson.co.uk wrote: I ran into a problem on a Sandybridge i5-2500s whilst measuring the performance of GTT write-combining access. I found subsequent runs were

Re: i915.ko WC writes are slow after ea8596bb2d8d379

On 10/08/2014 12:49 PM, Chris Wilson wrote: Indeed, this appears to be the explanation. (And here I thought PAT superseded mtrrs - i915.ko stopped trying to use assign an mtrr for its GTT quite a while ago.) Replacing the stop_machine there with on_each_cpu does the trick: It should,

Re: i915.ko WC writes are slow after ea8596bb2d8d379

(2014/10/09 2:47), Chuck Ebbert wrote: On Wed, 8 Oct 2014 10:03:36 +0100 Chris Wilson ch...@chris-wilson.co.uk wrote: and adding that back into the current build, e.g. diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 3632743..48a8a69 100644 --- a/arch/x86/Kconfig +++