Oh. Thanks Chris! > -----Original Message----- > From: Chris Wilson [mailto:chris@xxxxxxxxxxxxxxxxxx] > Sent: Friday, May 20, 2016 2:17 PM > To: Wang, Zhi A <zhi.a.wang@xxxxxxxxx> > Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; tvrtko.ursulin@xxxxxxxxxxxxxxx; > joonas.lahtinen@xxxxxxxxxxxxxxx; Tian, Kevin <kevin.tian@xxxxxxxxx>; Lv, > Zhiyuan <zhiyuan.lv@xxxxxxxxx> > Subject: Re: [PATCH 7/9] drm/i915: Introduce execlist context status change > notification > > On Tue, May 17, 2016 at 04:19:07AM -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. > > > > 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 | 6 ++++++ > > drivers/gpu/drm/i915/intel_lrc.c | 30 ++++++++++++++++++++++++++++++ > > drivers/gpu/drm/i915/intel_lrc.h | 7 +++++++ > > 3 files changed, 43 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h > > b/drivers/gpu/drm/i915/i915_drv.h index 91f69e5..9688006 100644 > > --- a/drivers/gpu/drm/i915/i915_drv.h > > +++ b/drivers/gpu/drm/i915/i915_drv.h > > @@ -882,9 +882,15 @@ struct intel_context { > > u64 lrc_desc; > > uint32_t *lrc_reg_state; > > bool initialised; > > +#if IS_ENABLED(CONFIG_DRM_I915_GVT) > > + struct atomic_notifier_head status_notifier_head; > > struct atomic_notifier_head status_notifier; > > > +#endif > > } engine[I915_NUM_ENGINES]; > > u32 ring_buffer_size; > > bool use_48bit_addressing_mode; > > +#if IS_ENABLED(CONFIG_DRM_I915_GVT) > > + bool enable_status_change_notification; > > unsigned status_notify; > > > +#endif > > > > struct list_head link; > > }; > > diff --git a/drivers/gpu/drm/i915/intel_lrc.c > > b/drivers/gpu/drm/i915/intel_lrc.c > > index d97623f..9069836 100644 > > --- a/drivers/gpu/drm/i915/intel_lrc.c > > +++ b/drivers/gpu/drm/i915/intel_lrc.c > > @@ -415,6 +415,20 @@ static void execlists_submit_requests(struct > drm_i915_gem_request *rq0, > > spin_unlock_irq(&dev_priv->uncore.lock); > > } > > > > +#if IS_ENABLED(CONFIG_DRM_I915_GVT) > > Actually, I think there will be other use cases for this notifier. > So let's not clutter the code with #ifdefs. Remove the ones from the struct and > do > OK. I guess the reason you want to turn a "bool" to "unsigned" is: if (status_notify & NOTFIY_CONTEXT_STATUS) notify context status change if (status_notify & NOTIFY_OTHER_THINGS) notify other things .... extend it in future. Or is there any other reason? Glad to know. :) > > +static inline void execlists_context_status_change( > > + struct drm_i915_gem_request *req, > > + unsigned long status) > > +{ > > if (!IS_ENABLED(CONFIG_DRM_I915_GVT)) > return; > > instead. The compiler should be fine with the dead-code elimination. > OK. Will do. > > > + if (!req->ctx->enable_status_change_notification) > > What locks are you holding here? > I'm holding engine->execlist_lock at this path. > if (!READ_ONCE(req->ctx->status_notify)) > return; > > > + return; > > + > > + atomic_notifier_call_chain( > > + &req->ctx->engine[req->engine->id].status_notifier_head, > > I think we have enough justification for req->ctx_engine; > Are you saying you're doing some refactors on req->ctx, or you want to get some local pointers in this function, so that the req->xxxxx could be much shorter? :) > > + status, req); > > +} > > +#endif > > + > > static void execlists_context_unqueue(struct intel_engine_cs *engine) > > { > > struct drm_i915_gem_request *req0 = NULL, *req1 = NULL; @@ -450,6 > > +464,13 @@ static void execlists_context_unqueue(struct intel_engine_cs > *engine) > > if (unlikely(!req0)) > > return; > > > > +#if IS_ENABLED(CONFIG_DRM_I915_GVT) > > + execlists_context_status_change(req0, CONTEXT_SCHEDULE_IN); > > + > > + if (req1) > > + execlists_context_status_change(req1, CONTEXT_SCHEDULE_IN); > > > +#endif > > + > > if (req0->elsp_submitted & engine->idle_lite_restore_wa) { > > /* > > * WaIdleLiteRestore: make sure we never cause a lite restore @@ > > -488,6 +509,10 @@ execlists_check_remove_request(struct intel_engine_cs > *engine, u32 ctx_id) > > if (--head_req->elsp_submitted > 0) > > return 0; > > > > +#if IS_ENABLED(CONFIG_DRM_I915_GVT) > > + execlists_context_status_change(head_req, CONTEXT_SCHEDULE_OUT); > > +#endif > > + > > list_del(&head_req->execlist_link); > > i915_gem_request_unreference(head_req); > > > > @@ -2534,6 +2559,11 @@ static int execlists_context_deferred_alloc(struct > intel_context *ctx, > > ctx->engine[engine->id].state = ctx_obj; > > ctx->engine[engine->id].initialised = engine->init_context == NULL; > > > > +#if IS_ENABLED(CONFIG_DRM_I915_GVT) > > + if (ctx->enable_status_change_notification) > > Always do the init. That allows us to start switching the notify on/off at > runtime. Good idea. Will do :) > -Chris > > -- > Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
