[Intel-gfx] [PATCH] RFC drm/i915: Slaughter the thundering i915_wait_request herd

[Gong, Zhipeng]

> -----Original Message-----
> From: Chris Wilson [mailto:chris at chris-wilson.co.uk]
> Sent: Monday, November 02, 2015 5:59 PM
> To: Gong, Zhipeng
> Cc: intel-gfx at lists.freedesktop.org; Rogozhkin, Dmitry V
> Subject: Re: [PATCH] RFC drm/i915: Slaughter the thundering
> i915_wait_request herd
> 
> On Mon, Nov 02, 2015 at 05:39:54AM +0000, Gong, Zhipeng wrote:
> > Chris-
> >
> > The patch cannot be applied on the latest drm-intel-nightly directly.
> > I modified it a little bit to make it applied.
> > The patch can help much in HSW, but a little bit in BDW.
> > The test is to transcode 26 streams, which creates 244 threads.
> >
> > CPU util      |	w/o patch  |   w/ patch
> > ----------------------------------------------------------
> > HSW async 1   |   102%     |     61%
> > HSW async 5   |   114%     |     46%
> > BDW async 1   |   116%     |     116%
> > BDW async 5   |   111%     |     107%
> 
> Could I get the perf report for the kernel time? One aspect that I find hard to
> believe is that it is not the execbuf/mutex-contention that is the ratelimiting
> step.

Sure, what command would you like to run with "perf"?

-Zhipeng