[PATCH 2/4] drm/cache: Try to be smarter about clflushing on x86

2014-12-15 Thread Ben Widawsky
On Sat, Dec 13, 2014 at 08:15:22PM -0800, Matt Turner wrote: > On Sat, Dec 13, 2014 at 7:08 PM, Ben Widawsky > wrote: > > Any GEM driver which has very large objects and a slow CPU is subject to > > very > > long waits simply for clflushing incoherent objects. Generally, each > > individual > >

[Intel-gfx] [PATCH 2/4] drm/cache: Try to be smarter about clflushing on x86

2014-12-15 Thread Ben Widawsky
On Sun, Dec 14, 2014 at 08:06:20PM -0800, Jesse Barnes wrote: > On 12/14/2014 4:59 AM, Chris Wilson wrote: > >One of the things wbinvd is considered evil for is that it blocks the > >CPU for an indeterminate amount of time - upsetting latency critcial > >aspects of the OS. For example, the x86/mm

[Intel-gfx] [PATCH 2/4] drm/cache: Try to be smarter about clflushing on x86

2014-12-14 Thread Jesse Barnes
On 12/14/2014 4:59 AM, Chris Wilson wrote: > One of the things wbinvd is considered evil for is that it blocks the > CPU for an indeterminate amount of time - upsetting latency critcial > aspects of the OS. For example, the x86/mm has similar code to use > wbinvd for large clflushes that caused a

[Intel-gfx] [PATCH 2/4] drm/cache: Try to be smarter about clflushing on x86

2014-12-14 Thread Chris Wilson
On Sat, Dec 13, 2014 at 07:08:22PM -0800, Ben Widawsky wrote: > Any GEM driver which has very large objects and a slow CPU is subject to very > long waits simply for clflushing incoherent objects. Generally, each > individual > object is not a problem, but if you have very large objects, or very

[PATCH 2/4] drm/cache: Try to be smarter about clflushing on x86

2014-12-13 Thread Matt Turner
On Sat, Dec 13, 2014 at 7:08 PM, Ben Widawsky wrote: > Any GEM driver which has very large objects and a slow CPU is subject to very > long waits simply for clflushing incoherent objects. Generally, each > individual > object is not a problem, but if you have very large objects, or very many >

[PATCH 2/4] drm/cache: Try to be smarter about clflushing on x86

2014-12-13 Thread Ben Widawsky
Any GEM driver which has very large objects and a slow CPU is subject to very long waits simply for clflushing incoherent objects. Generally, each individual object is not a problem, but if you have very large objects, or very many objects, the flushing begins to show up in profiles. Because on