> -----Original Message----- > From: Joonas Lahtinen [mailto:joonas.lahtinen@xxxxxxxxxxxxxxx] > Sent: Friday, June 03, 2016 12:40 PM > To: Wang, Zhi A <zhi.a.wang@xxxxxxxxx>; intel-gfx@xxxxxxxxxxxxxxxxxxxxx; > tvrtko.ursulin@xxxxxxxxxxxxxxx; Tian, Kevin <kevin.tian@xxxxxxxxx>; Lv, Zhiyuan > <zhiyuan.lv@xxxxxxxxx>; chris@xxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH v6 7/9] drm/i915: Introduce execlist context status change > notification > > On to, 2016-06-02 at 12:36 -0400, Zhi Wang wrote: > > This patch introduces an approach to track the execlist context status > > change. > > > > GVT-g uses GVT context as the "shadow context". The content inside GVT > > context will be copied back to guest after the context is idle. So > > GVT-g has to know the status of the execlist context. > > > > This function is configurable in the context creation service. > > Currently, Only GVT-g will create the "status-change-notification" > > enabled GEM context. > > > > v6: > > > > - When !CONFIG_DRM_I915_GVT, make GVT code as dead code then > compiler > > could automatically eliminate them for us. (Chris) > > - Always initialize the notifier header, so it could be switched > > on/off at runtime. (Chris) > > > > v5: > > > > - Only compile this feature when CONFIG_DRM_I915_GVT is > > enabled.(Tvrtko) > > > > Signed-off-by: Zhi Wang <zhi.a.wang@xxxxxxxxx> > > --- > > drivers/gpu/drm/i915/i915_drv.h | 2 ++ > > drivers/gpu/drm/i915/intel_lrc.c | 24 ++++++++++++++++++++++++ > > drivers/gpu/drm/i915/intel_lrc.h | 5 +++++ > > 3 files changed, 31 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h > > b/drivers/gpu/drm/i915/i915_drv.h index f6cb60a..dee72d3 100644 > > --- a/drivers/gpu/drm/i915/i915_drv.h > > +++ b/drivers/gpu/drm/i915/i915_drv.h > > @@ -877,9 +877,11 @@ struct i915_gem_context { > > u64 lrc_desc; > > int pin_count; > > bool initialised; > > + struct atomic_notifier_head status_notifier; > > I think this could be outside engine block, just one per context. > > > } engine[I915_NUM_ENGINES]; > > u32 lrc_ring_buffer_size; > > u32 lrc_addressing_mode_bits; > > + bool enable_lrc_status_change_notification; > > > > struct list_head link; > > > > diff --git a/drivers/gpu/drm/i915/intel_lrc.c > > b/drivers/gpu/drm/i915/intel_lrc.c > > index ffb436c..96d20c8 100644 > > --- a/drivers/gpu/drm/i915/intel_lrc.c > > +++ b/drivers/gpu/drm/i915/intel_lrc.c > > @@ -404,6 +404,22 @@ static void execlists_submit_requests(struct > drm_i915_gem_request *rq0, > > spin_unlock_irq(&dev_priv->uncore.lock); > > } > > > > +static inline void execlists_context_status_change( > > + struct drm_i915_gem_request *rq, > > + unsigned long status) > > +{ > > + /* The compiler should be fine with the dead-code elimination */ > > The comment could rather be "Currently, only GVT-g code uses status > notifications" :) > > > + if (!IS_ENABLED(CONFIG_DRM_I915_GVT)) > > + return; > > + > > + if (!rq->ctx->enable_lrc_status_change_notification) > > + return; > > + > > I think above line should be dropped, just don't register notifier for context that > does not want notifications, and if the chain is empty, no call is made. > I keep this in v7 as I think a "if" here is much cheaper than the rcu stuff in atomic_notifier_call_chain() with a lot of "if" even when the chain is empty. :) > > + atomic_notifier_call_chain( > > + &rq->ctx->engine[rq->engine->id].status_notifier, > > + status, rq); > > +} > > + > > static void execlists_context_unqueue(struct intel_engine_cs *engine) > > { > > struct drm_i915_gem_request *req0 = NULL, *req1 = NULL; @@ -439,6 > > +455,11 @@ static void execlists_context_unqueue(struct intel_engine_cs > *engine) > > if (unlikely(!req0)) > > return; > > > > + execlists_context_status_change(req0, CONTEXT_SCHEDULE_IN); > > + > > + if (req1) > > + execlists_context_status_change(req1, CONTEXT_SCHEDULE_IN); > > + > > if (req0->elsp_submitted & engine->idle_lite_restore_wa) { > > /* > > * WaIdleLiteRestore: make sure we never cause a lite restore @@ > > -477,6 +498,8 @@ execlists_check_remove_request(struct intel_engine_cs > *engine, u32 ctx_id) > > if (--head_req->elsp_submitted > 0) > > return 0; > > > > + execlists_context_status_change(head_req, CONTEXT_SCHEDULE_OUT); > > + > > list_del(&head_req->execlist_link); > > i915_gem_request_unreference(head_req); > > > > @@ -2489,6 +2512,7 @@ static int execlists_context_deferred_alloc(struct > i915_gem_context *ctx, > > ce->ringbuf = ringbuf; > > ce->state = ctx_obj; > > ce->initialised = engine->init_context == NULL; > > + ATOMIC_INIT_NOTIFIER_HEAD(&ce->status_notifier); > > > > return 0; > > > > diff --git a/drivers/gpu/drm/i915/intel_lrc.h > > b/drivers/gpu/drm/i915/intel_lrc.h > > index e133c33..7a7ae8d 100644 > > --- a/drivers/gpu/drm/i915/intel_lrc.h > > +++ b/drivers/gpu/drm/i915/intel_lrc.h > > @@ -68,6 +68,11 @@ enum { > > #define GEN8_CSB_READ_PTR(csb_status) \ > > (((csb_status) & GEN8_CSB_READ_PTR_MASK) >> 8) > > > > +enum { > > + CONTEXT_SCHEDULE_IN = 0, > > + CONTEXT_SCHEDULE_OUT, > > +}; > > + > > Again, prefixes? At least INTEL_ > > With above; > > Reviewed-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> > > Regards, Joonas > > > /* Logical Rings */ > > int intel_logical_ring_alloc_request_extras(struct > > drm_i915_gem_request *request); > > int intel_logical_ring_reserve_space(struct drm_i915_gem_request > > *request); > -- > Joonas Lahtinen > Open Source Technology Center > Intel Corporation _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
