On Thu, Feb 11, 2016 at 01:01:34PM +0000, Tvrtko Ursulin wrote: > On 29/01/16 16:49, Chris Wilson wrote: > >As we add the VMA to the request early, it may be cancelled during > >execbuf reservation. This will leave the context object pointing to a > > I don't get it, request is created after the reservation. That's the problem - we add vma for a given request (well ring/seqno pair) before that request exists. -Daniel > > >dangling request; i915_wait_request() simply skips the wait and so we > >may unbind the object whilst it is still active. > > > >However, if at any point we make a change to the hardware (and equally > >importantly our bookkeeping in the driver), we cannot cancel the request > >as what has already been written must be submitted. Submitting a partial > >request is far easier than trying to unwind the incomplete change. > > > >Unfortunately this patch undoes the excess breadcrumb usage that olr > >prevented, e.g. if we interrupt batchbuffer submission then we submit > >the requests along with the memory writes and interrupt (even though we > >do no real work). Disassociating requests from breadcrumbs (and > >semaphores) is a topic for a past/future series, but now much more > >important. > > > >v2: Rebase > > > >Note that igt/gem_concurrent_blit tiggers both misrendering and a GPF > >that is fixed by this patch. > > > >Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93907 > >Testcase: igt/gem_concurrent_blit > >Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > >Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> > >Cc: stable@xxxxxxxxxxxxxxx > >--- > > drivers/gpu/drm/i915/i915_drv.h | 1 - > > drivers/gpu/drm/i915/i915_gem.c | 7 ++----- > > drivers/gpu/drm/i915/i915_gem_context.c | 21 +++++++++------------ > > drivers/gpu/drm/i915/i915_gem_execbuffer.c | 16 +++++----------- > > drivers/gpu/drm/i915/intel_display.c | 2 +- > > drivers/gpu/drm/i915/intel_lrc.c | 1 - > > 6 files changed, 17 insertions(+), 31 deletions(-) > > > >diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > >index a2d2f08b7515..f828a7ffed37 100644 > >--- a/drivers/gpu/drm/i915/i915_drv.h > >+++ b/drivers/gpu/drm/i915/i915_drv.h > >@@ -2823,7 +2823,6 @@ 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 e9b19bca1383..f764f33580fc 100644 > >--- a/drivers/gpu/drm/i915/i915_gem.c > >+++ b/drivers/gpu/drm/i915/i915_gem.c > >@@ -3407,12 +3407,9 @@ 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_ring_idle(ring); > >diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c > >index 83a097c94911..5da7adc3f7b2 100644 > >--- a/drivers/gpu/drm/i915/i915_gem_context.c > >+++ b/drivers/gpu/drm/i915/i915_gem_context.c > >@@ -652,7 +652,6 @@ static int do_switch(struct drm_i915_gem_request *req) > > struct drm_i915_private *dev_priv = ring->dev->dev_private; > > struct intel_context *from = ring->last_context; > > u32 hw_flags = 0; > >- bool uninitialized = false; > > int ret, i; > > > > if (from != NULL && ring == &dev_priv->ring[RCS]) { > >@@ -759,6 +758,15 @@ static int do_switch(struct drm_i915_gem_request *req) > > to->remap_slice &= ~(1<<i); > > } > > > >+ if (!to->legacy_hw_ctx.initialized) { > >+ if (ring->init_context) { > >+ ret = ring->init_context(req); > >+ if (ret) > >+ goto unpin_out; > >+ } > >+ to->legacy_hw_ctx.initialized = true; > >+ } > >+ > > /* The backing object for the context is done after switching to the > > * *next* context. Therefore we cannot retire the previous context until > > * the next context has already started running. In fact, the below code > >@@ -782,21 +790,10 @@ static int do_switch(struct drm_i915_gem_request *req) > > i915_gem_context_unreference(from); > > } > > > >- uninitialized = !to->legacy_hw_ctx.initialized; > >- to->legacy_hw_ctx.initialized = true; > >- > > done: > > i915_gem_context_reference(to); > > ring->last_context = to; > > > >- if (uninitialized) { > >- if (ring->init_context) { > >- ret = ring->init_context(req); > >- if (ret) > >- DRM_ERROR("ring init context: %d\n", ret); > >- } > >- } > >- > > return 0; > > > > unpin_out: > >diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > >index 8fd00d279447..61bb15507b30 100644 > >--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > >+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > >@@ -1133,7 +1133,7 @@ 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. */ > >@@ -1318,7 +1318,6 @@ 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); > > Hm this whole block block from trace_... to > i915_gem_execbuffer_retire_commands could be moved to do_execbuffer as and > independent cleanup patch if under "if (ret == 0)". > > So the concern is that something has been written to the ringbuffer but not > all of it? > > Why do we have to submit that, I am assuming whatever was written is not > interesting to be executed unless the whole bb went in. > > So could we just rewind the pointers? Store them at the beginning and rewind > if something failed. > > > > > return 0; > > } > >@@ -1616,8 +1615,10 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data, > > } > > > > ret = i915_gem_request_add_to_client(req, file); > >- if (ret) > >+ if (ret) { > >+ i915_gem_request_cancel(req); > > goto err_batch_unpin; > >+ } > > Doesn't look like this can fail so a side cleanup only? > > Regards, > > Tvrtko -- 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
