[Intel-gfx] [PATCH V2] drm/i915/gem: Use large rings for compute contexts

[Upadhyay, Tejas]

> -----Original Message-----
> From: Andi Shyti <andi.shyti at linux.intel.com>
> Sent: Wednesday, May 31, 2023 2:42 AM
> To: Upadhyay, Tejas <tejas.upadhyay at intel.com>
> Cc: intel-gfx at lists.freedesktop.org; Wilson, Chris P
> <chris.p.wilson at intel.com>
> Subject: Re: [Intel-gfx] [PATCH V2] drm/i915/gem: Use large rings for
> compute contexts
> 
> Hi Tejas,
> 
> Just one note...

Thanks, Noted.

> 
> On Wed, May 17, 2023 at 07:27:54PM +0530, Tejas Upadhyay wrote:
> > From: Chris Wilson <chris.p.wilson at intel.com>
> >
> > Allow compute contexts to submit the maximal amount of work without
> > blocking userspace.
> >
> > The original size for user LRC ring's (SZ_16K) was chosen to minimise
> > memory consumption, without being so small as to frequently stall in
> > the middle of workloads. With the main consumers being GL / media
> > pipelines of 2 or 3 batches per frame, we want to support ~10 requests
> > in flight to allow for the application to control throttling without
> > stalling within a frame.
> >
> > v2:
> >   - cover with else part
> >
> > Signed-off-by: Chris Wilson <chris.p.wilson at intel.com>
> 
> ... please, next time add your SoB here as you are sending it.
> 
> No need to resend, I will add it.
> 
> Andi
> 
> > ---
> >  drivers/gpu/drm/i915/gem/i915_gem_context.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > index 5402a7bbcb1d..9a9ff84c90d7 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > @@ -964,7 +964,11 @@ static int intel_context_set_gem(struct
> intel_context *ce,
> >  	RCU_INIT_POINTER(ce->gem_context, ctx);
> >
> >  	GEM_BUG_ON(intel_context_is_pinned(ce));
> > -	ce->ring_size = SZ_16K;
> > +
> > +	if (ce->engine->class == COMPUTE_CLASS)
> > +		ce->ring_size = SZ_512K;
> > +	else
> > +		ce->ring_size = SZ_16K;
> >
> >  	i915_vm_put(ce->vm);
> >  	ce->vm = i915_gem_context_get_eb_vm(ctx);
> > --
> > 2.25.1