On Tue, Apr 12, 2016 at 09:03:09PM +0100, Chris Wilson wrote: > Conceptually, each request is a record of a hardware transaction - we > build up a list of pending commands and then either commit them to > hardware, or cancel them. However, whilst building up the list of > pending commands, we may modify state outside of the request and make > references to the pending request. If we do so and then cancel that > request, external objects then point to the deleted request leading to > both graphical and memory corruption. > > The easiest example is to consider object/VMA tracking. When we mark an > object as active in a request, we store a pointer to this, the most > recent request, in the object. Then we want to free that object, we wait > for the most recent request to be idle before proceeding (otherwise the > hardware will write to pages now owned by the system, or we will attempt > to read from those pages before the hardware is finished writing). If > the request was cancelled instead, that wait completes immediately. As a > result, all requests must be committed and not cancelled if the external > state is unknown. > > All that remains of i915_gem_request_cancel() users are just a couple of > extremely unlikely allocation failures, so remove the API entirely. > > A consequence of committing all incomplete requests is that we generate > excess breadcrumbs and fill the ring much more often with dummy work. We > have completely undone the outstanding_last_seqno optimisation. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93907 > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> > Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx Cc: John Harrison <John.C.Harrison@xxxxxxxxx> I'd like John's ack on this on too, but patch itself looks sound. Fast r-b since we've discussed this a while ago already ... Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > --- > drivers/gpu/drm/i915/i915_drv.h | 2 -- > drivers/gpu/drm/i915/i915_gem.c | 50 ++++++++++++------------------ > drivers/gpu/drm/i915/i915_gem_execbuffer.c | 15 +++------ > drivers/gpu/drm/i915/intel_display.c | 2 +- > drivers/gpu/drm/i915/intel_lrc.c | 4 +-- > drivers/gpu/drm/i915/intel_overlay.c | 8 ++--- > 6 files changed, 30 insertions(+), 51 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 061ecc43d935..de84dd7be971 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -2331,7 +2331,6 @@ struct drm_i915_gem_request { > struct drm_i915_gem_request * __must_check > i915_gem_request_alloc(struct intel_engine_cs *engine, > struct intel_context *ctx); > -void i915_gem_request_cancel(struct drm_i915_gem_request *req); > void i915_gem_request_free(struct kref *req_ref); > int i915_gem_request_add_to_client(struct drm_i915_gem_request *req, > struct drm_file *file); > @@ -2883,7 +2882,6 @@ int i915_gem_sw_finish_ioctl(struct drm_device *dev, void *data, > struct drm_file *file_priv); > void i915_gem_execbuffer_move_to_active(struct list_head *vmas, > struct drm_i915_gem_request *req); > -void i915_gem_execbuffer_retire_commands(struct i915_execbuffer_params *params); > int i915_gem_ringbuffer_submission(struct i915_execbuffer_params *params, > struct drm_i915_gem_execbuffer2 *args, > struct list_head *vmas); > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c > index b6879d43dd74..c6f09e7839ea 100644 > --- a/drivers/gpu/drm/i915/i915_gem.c > +++ b/drivers/gpu/drm/i915/i915_gem.c > @@ -2785,7 +2785,8 @@ __i915_gem_request_alloc(struct intel_engine_cs *engine, > * fully prepared. Thus it can be cleaned up using the proper > * free code. > */ > - i915_gem_request_cancel(req); > + intel_ring_reserved_space_cancel(req->ringbuf); > + i915_gem_request_unreference(req); > return ret; > } > > @@ -2822,13 +2823,6 @@ i915_gem_request_alloc(struct intel_engine_cs *engine, > return err ? ERR_PTR(err) : req; > } > > -void i915_gem_request_cancel(struct drm_i915_gem_request *req) > -{ > - intel_ring_reserved_space_cancel(req->ringbuf); > - > - i915_gem_request_unreference(req); > -} > - > struct drm_i915_gem_request * > i915_gem_find_active_request(struct intel_engine_cs *engine) > { > @@ -3438,12 +3432,9 @@ int i915_gpu_idle(struct drm_device *dev) > return PTR_ERR(req); > > ret = i915_switch_context(req); > - if (ret) { > - i915_gem_request_cancel(req); > - return ret; > - } > - > i915_add_request_no_flush(req); > + if (ret) > + return ret; > } > > ret = intel_engine_idle(engine); > @@ -4943,34 +4934,33 @@ i915_gem_init_hw(struct drm_device *dev) > req = i915_gem_request_alloc(engine, NULL); > if (IS_ERR(req)) { > ret = PTR_ERR(req); > - i915_gem_cleanup_engines(dev); > - goto out; > + break; > } > > if (engine->id == RCS) { > - for (j = 0; j < NUM_L3_SLICES(dev); j++) > - i915_gem_l3_remap(req, j); > + for (j = 0; j < NUM_L3_SLICES(dev); j++) { > + ret = i915_gem_l3_remap(req, j); > + if (ret) > + goto err_request; > + } > } > > ret = i915_ppgtt_init_ring(req); > - if (ret && ret != -EIO) { > - DRM_ERROR("PPGTT enable %s failed %d\n", > - engine->name, ret); > - i915_gem_request_cancel(req); > - i915_gem_cleanup_engines(dev); > - goto out; > - } > + if (ret) > + goto err_request; > > ret = i915_gem_context_enable(req); > - if (ret && ret != -EIO) { > - DRM_ERROR("Context enable %s failed %d\n", > + if (ret) > + goto err_request; > + > +err_request: > + i915_add_request_no_flush(req); > + if (ret) { > + DRM_ERROR("Failed to enable %s, error=%d\n", > engine->name, ret); > - i915_gem_request_cancel(req); > i915_gem_cleanup_engines(dev); > - goto out; > + break; > } > - > - i915_add_request_no_flush(req); > } > > out: > diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > index 6ee4f00f620c..6f4f2a6cdf93 100644 > --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > @@ -1137,7 +1137,7 @@ i915_gem_execbuffer_move_to_active(struct list_head *vmas, > } > } > > -void > +static void > i915_gem_execbuffer_retire_commands(struct i915_execbuffer_params *params) > { > /* Unconditionally force add_request to emit a full flush. */ > @@ -1322,7 +1322,6 @@ i915_gem_ringbuffer_submission(struct i915_execbuffer_params *params, > trace_i915_gem_ring_dispatch(params->request, params->dispatch_flags); > > i915_gem_execbuffer_move_to_active(vmas, params->request); > - i915_gem_execbuffer_retire_commands(params); > > return 0; > } > @@ -1624,7 +1623,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data, > > ret = i915_gem_request_add_to_client(req, file); > if (ret) > - goto err_batch_unpin; > + goto err_request; > > /* > * Save assorted stuff away to pass through to *_submission(). > @@ -1641,6 +1640,8 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data, > params->request = req; > > ret = dev_priv->gt.execbuf_submit(params, args, &eb->vmas); > +err_request: > + i915_gem_execbuffer_retire_commands(params); > > err_batch_unpin: > /* > @@ -1657,14 +1658,6 @@ err: > i915_gem_context_unreference(ctx); > eb_destroy(eb); > > - /* > - * If the request was created but not successfully submitted then it > - * must be freed again. If it was submitted then it is being tracked > - * on the active request list and no clean up is required here. > - */ > - if (ret && !IS_ERR_OR_NULL(req)) > - i915_gem_request_cancel(req); > - > mutex_unlock(&dev->struct_mutex); > > pre_mutex_err: > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index b1b457864e17..3cae596d10a3 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -11664,7 +11664,7 @@ cleanup_unpin: > intel_unpin_fb_obj(fb, crtc->primary->state->rotation); > cleanup_pending: > if (!IS_ERR_OR_NULL(request)) > - i915_gem_request_cancel(request); > + i915_add_request_no_flush(request); > atomic_dec(&intel_crtc->unpin_work_count); > mutex_unlock(&dev->struct_mutex); > cleanup: > diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c > index b8f6b96472a6..6fc24deaa16a 100644 > --- a/drivers/gpu/drm/i915/intel_lrc.c > +++ b/drivers/gpu/drm/i915/intel_lrc.c > @@ -1010,7 +1010,6 @@ int intel_execlists_submission(struct i915_execbuffer_params *params, > trace_i915_gem_ring_dispatch(params->request, params->dispatch_flags); > > i915_gem_execbuffer_move_to_active(vmas, params->request); > - i915_gem_execbuffer_retire_commands(params); > > return 0; > } > @@ -2679,13 +2678,12 @@ int intel_lr_context_deferred_alloc(struct intel_context *ctx, > } > > ret = engine->init_context(req); > + i915_add_request_no_flush(req); > if (ret) { > DRM_ERROR("ring init context: %d\n", > ret); > - i915_gem_request_cancel(req); > goto error_ringbuf; > } > - i915_add_request_no_flush(req); > } > return 0; > > diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c > index 6694e9230cd5..bcc3b6a016d8 100644 > --- a/drivers/gpu/drm/i915/intel_overlay.c > +++ b/drivers/gpu/drm/i915/intel_overlay.c > @@ -247,7 +247,7 @@ static int intel_overlay_on(struct intel_overlay *overlay) > > ret = intel_ring_begin(req, 4); > if (ret) { > - i915_gem_request_cancel(req); > + i915_add_request_no_flush(req); > return ret; > } > > @@ -290,7 +290,7 @@ static int intel_overlay_continue(struct intel_overlay *overlay, > > ret = intel_ring_begin(req, 2); > if (ret) { > - i915_gem_request_cancel(req); > + i915_add_request_no_flush(req); > return ret; > } > > @@ -356,7 +356,7 @@ static int intel_overlay_off(struct intel_overlay *overlay) > > ret = intel_ring_begin(req, 6); > if (ret) { > - i915_gem_request_cancel(req); > + i915_add_request_no_flush(req); > return ret; > } > > @@ -431,7 +431,7 @@ static int intel_overlay_release_old_vid(struct intel_overlay *overlay) > > ret = intel_ring_begin(req, 2); > if (ret) { > - i915_gem_request_cancel(req); > + i915_add_request_no_flush(req); > return ret; > } > > -- > 2.8.0.rc3 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
