Hi Tvrtko, > -----Original Message----- > From: Tvrtko Ursulin [mailto:tvrtko.ursu...@linux.intel.com] > Sent: Friday, September 21, 2018 6:10 PM > To: J Karanje, Kedar <kedar.j.kara...@intel.com>; intel- > g...@lists.freedesktop.org > Cc: Diwakar, Praveen <praveen.diwa...@intel.com>; Marathe, Yogesh > <yogesh.mara...@intel.com>; Navik, Ankit P <ankit.p.na...@intel.com>; > Muthukumar, Aravindan <aravindan.muthuku...@intel.com> > Subject: Re: [Intel-gfx] [PATCH 1/4] drm/i915: Get active pending request for > given context > > > On 21/09/2018 10:13, kedar.j.kara...@intel.com wrote: > > From: Praveen Diwakar <praveen.diwa...@intel.com> > > > > This patch gives us the active pending request count which is yet to > > be submitted to the GPU > > > > Change-Id: I10c2828ad0f1a0b7af147835737134e07a2d5b6d > > Signed-off-by: Praveen Diwakar <praveen.diwa...@intel.com> > > Signed-off-by: Yogesh Marathe <yogesh.mara...@intel.com> > > Signed-off-by: Aravindan Muthukumar <aravindan.muthuku...@intel.com> > > Signed-off-by: Kedar J Karanje <kedar.j.kara...@intel.com> > > Signed-off-by: Ankit Navik <ankit.p.na...@intel.com> > > --- > > drivers/gpu/drm/i915/i915_drv.c | 1 + > > drivers/gpu/drm/i915/i915_drv.h | 5 +++++ > > drivers/gpu/drm/i915/i915_gem_context.c | 1 + > > drivers/gpu/drm/i915/i915_gem_context.h | 6 ++++++ > > drivers/gpu/drm/i915/i915_gem_execbuffer.c | 5 +++++ > > drivers/gpu/drm/i915/intel_lrc.c | 6 ++++++ > > 6 files changed, 24 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.c > > b/drivers/gpu/drm/i915/i915_drv.c index f8cfd16..d37c46e 100644 > > --- a/drivers/gpu/drm/i915/i915_drv.c > > +++ b/drivers/gpu/drm/i915/i915_drv.c > > @@ -903,6 +903,7 @@ static int i915_driver_init_early(struct > drm_i915_private *dev_priv, > > mutex_init(&dev_priv->av_mutex); > > mutex_init(&dev_priv->wm.wm_mutex); > > mutex_init(&dev_priv->pps_mutex); > > + mutex_init(&dev_priv->pred_mutex); > > > > i915_memcpy_init_early(dev_priv); > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h > > b/drivers/gpu/drm/i915/i915_drv.h index 4aca534..137ec33 100644 > > --- a/drivers/gpu/drm/i915/i915_drv.h > > +++ b/drivers/gpu/drm/i915/i915_drv.h > > @@ -1609,6 +1609,11 @@ struct drm_i915_private { > > * controller on different i2c buses. */ > > struct mutex gmbus_mutex; > > > > + /** pred_mutex protects against councurrent usage of pending > > + * request counter for multiple contexts > > + */ > > + struct mutex pred_mutex; > > + > > /** > > * Base address of the gmbus and gpio block. > > */ > > diff --git a/drivers/gpu/drm/i915/i915_gem_context.c > > b/drivers/gpu/drm/i915/i915_gem_context.c > > index b10770c..30932d9 100644 > > --- a/drivers/gpu/drm/i915/i915_gem_context.c > > +++ b/drivers/gpu/drm/i915/i915_gem_context.c > > @@ -387,6 +387,7 @@ i915_gem_create_context(struct drm_i915_private > *dev_priv, > > } > > > > trace_i915_context_create(ctx); > > + ctx->req_cnt = 0; > > > > return ctx; > > } > > diff --git a/drivers/gpu/drm/i915/i915_gem_context.h > > b/drivers/gpu/drm/i915/i915_gem_context.h > > index b116e49..243ea22 100644 > > --- a/drivers/gpu/drm/i915/i915_gem_context.h > > +++ b/drivers/gpu/drm/i915/i915_gem_context.h > > @@ -194,6 +194,12 @@ struct i915_gem_context { > > * context close. > > */ > > struct list_head handles_list; > > + > > + /** req_cnt: tracks the pending commands, based on which we decide > to > > + * go for low/medium/high load configuration of the GPU, this is > > + * controlled via a mutex > > + */ > > + u64 req_cnt; > > 64-bit is too wide and mutex causes you problems later in the series. > I'd suggest atomic_t. Changes done in v2. > > > }; > > > > static inline bool i915_gem_context_is_closed(const struct > > i915_gem_context *ctx) diff --git > > a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > index 3f0c612..f799ff9 100644 > > --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > @@ -2178,6 +2178,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, > > struct drm_syncobj **fences) > > { > > struct i915_execbuffer eb; > > + struct drm_i915_private *dev_priv = to_i915(dev); > > struct dma_fence *in_fence = NULL; > > struct sync_file *out_fence = NULL; > > int out_fence_fd = -1; > > @@ -2390,6 +2391,10 @@ i915_gem_do_execbuffer(struct drm_device *dev, > > */ > > eb.request->batch = eb.batch; > > > > + mutex_lock(&dev_priv->pred_mutex); > > + eb.ctx->req_cnt++; > > + mutex_unlock(&dev_priv->pred_mutex); > > + > > trace_i915_request_queue(eb.request, eb.batch_flags); > > err = eb_submit(&eb); > > err_request: > > diff --git a/drivers/gpu/drm/i915/intel_lrc.c > > b/drivers/gpu/drm/i915/intel_lrc.c > > index 1744792..039fbdb 100644 > > --- a/drivers/gpu/drm/i915/intel_lrc.c > > +++ b/drivers/gpu/drm/i915/intel_lrc.c > > @@ -728,6 +728,12 @@ static void execlists_dequeue(struct intel_engine_cs > *engine) > > trace_i915_request_in(rq, port_index(port, execlists)); > > last = rq; > > submit = true; > > + > > + mutex_lock(&rq->i915->pred_mutex); > > + if (rq->gem_context->req_cnt > 0) { > > Presumably you hit underflow here and then added the protection. This was a > hint the accounting does not work as expected. Preemption for instance would > wreak havoc with it. :) > > Have a look at my per engine queued/runnable counters for how to do it > correctly, only that you would need to make it per context and merge into one > aggregated queued+runnable instead of two separate counters, if you wanted > to preserve your heuristics. > > https://patchwork.freedesktop.org/patch/227981/ > https://patchwork.freedesktop.org/patch/227976/
We will wait for these patches to get merged and we will continue to investigate on how to incorporate this in our changes. Regards, Ankit > > Regards, > > Tvrtko > > > + rq->gem_context->req_cnt--; > > + } > > + mutex_unlock(&rq->i915->pred_mutex); > > } > > > > rb_erase_cached(&p->node, &execlists->queue); > > _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
