| Message ID | 1464885380-7056-8-git-send-email-zhi.a.wang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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@intel.com> > --- > 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. > + 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@linux.intel.com> 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);
> -----Original Message----- > From: Joonas Lahtinen [mailto:joonas.lahtinen@linux.intel.com] > Sent: Friday, June 03, 2016 12:40 PM > To: Wang, Zhi A <zhi.a.wang@intel.com>; intel-gfx@lists.freedesktop.org; > tvrtko.ursulin@linux.intel.com; Tian, Kevin <kevin.tian@intel.com>; Lv, Zhiyuan > <zhiyuan.lv@intel.com>; chris@chris-wilson.co.uk > 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@intel.com> > > --- > > 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@linux.intel.com> > > 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
On ti, 2016-06-07 at 15:29 +0000, Wang, Zhi A wrote: > > > > > -----Original Message----- > > From: Joonas Lahtinen [mailto:joonas.lahtinen@linux.intel.com] > > Sent: Friday, June 03, 2016 12:40 PM > > To: Wang, Zhi A <zhi.a.wang@intel.com>; intel-gfx@lists.freedesktop.org; > > tvrtko.ursulin@linux.intel.com; Tian, Kevin <kevin.tian@intel.com>; Lv, Zhiyuan > > <zhiyuan.lv@intel.com>; chris@chris-wilson.co.uk > > 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: > > > > > > + 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. :) If empty notifier call chain is too heavy, then we should improve it instead of going around. Do we have some benchmarks on the difference? Regards, Joonas
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; } 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 */ + if (!IS_ENABLED(CONFIG_DRM_I915_GVT)) + return; + + if (!rq->ctx->enable_lrc_status_change_notification) + return; + + 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, +}; + /* 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);
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@intel.com> --- 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(+)