Re: [PATCH] drm/i915: Restrict GPU boost to the RCS engine

From: Daniel Vetter <daniel@ffwll.ch>
To: Deepak S <deepak.s@linux.intel.com>
Cc: intel-gfx <intel-gfx@lists.freedesktop.org>
Subject: Re: [PATCH] drm/i915: Restrict GPU boost to the RCS engine
Date: Tue, 8 Jul 2014 10:25:43 +0200	[thread overview]
Message-ID: <20140708082543.GO17271@phenom.ffwll.local> (raw)
In-Reply-To: <53BCC764.2010108@linux.intel.com>

On Wed, Jul 09, 2014 at 10:09:00AM +0530, Deepak S wrote:
> 
> On Monday 07 July 2014 02:35 PM, Daniel Vetter wrote:
> >On Tue, Jun 24, 2014 at 05:22:17PM +0530, Deepak S wrote:
> >>Hi Chris/Daniel,
> >>
> >>The patch is  helping in some of the side-effects due to gpu boost. I
> >>still need to get more data. I will keep the thread updated.
> >Ping. Might as well review it, too.
> >-Daniel
> >
> >>Thanks
> >>Deepak
> >>
> >>On Thursday 12 June 2014 03:02 PM, Daniel Vetter wrote:
> >>>Adding Deepak for testing, this hopefully alleviates the bad
> >>>side-effects of the gpu booster he's seeing.
> >>>-Daniel
> >>>
> >>>On Thu, Jun 12, 2014 at 11:28 AM, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> >>>>Make the assumption that media workloads are not as latency sensitive
> >>>>for __wait_seqno, and that upclocking the GPU does not affect the BLT
> >>>>engine. Under that assumption, we only wait to forcibly upclock the GPU
> >>>>when we are stalling for results from the render pipeline.
> >>>>
> >>>>Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> >>>>---
> >>>>  drivers/gpu/drm/i915/i915_gem.c | 2 +-
> >>>>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>>>
> >>>>diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> >>>>index 5951618a6b08..242b595a0403 100644
> >>>>--- a/drivers/gpu/drm/i915/i915_gem.c
> >>>>+++ b/drivers/gpu/drm/i915/i915_gem.c
> >>>>@@ -1409,7 +1409,7 @@ static int __wait_seqno(struct intel_engine_cs *ring, u32 seqno,
> >>>>
> >>>>         timeout_expire = timeout ? jiffies + timespec_to_jiffies_timeout(timeout) : 0;
> >>>>
> >>>>-       if (INTEL_INFO(dev)->gen >= 6 && can_wait_boost(file_priv)) {
> >>>>+       if (INTEL_INFO(dev)->gen >= 6 && ring->id == RCS && can_wait_boost(file_priv)) {
> >>>>                 gen6_rps_boost(dev_priv);
> >>>>                 if (file_priv)
> >>>>                         mod_delayed_work(dev_priv->wq,
> >>>>--
> >>>>2.0.0
> >>>>
> >>>>_______________________________________________
> >>>>Intel-gfx mailing list
> >>>>Intel-gfx@lists.freedesktop.org
> >>>>http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> >>>
> Sorry for the delayed response. I am fine with this patch. This is helping us in some of the workload senarios.
> 
> Just one concern here. Since we are avoiding boost for Media related workload, we might end up running GPU at RPn. Which might impact media workload.
> I think we need another patch to run GPU at RPe if the boost is not enabled for media.
> 
> Reviewed-by: Deepak S<deepak.s@linux.intel.com>

Queued for -next, thanks for the patch.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch