On Fri, Sep 24, 2021 at 06:38:25PM +0200, Janusz Krzysztofik wrote: > We currently do an explicit flush of the buffer pools within the call path > of drm_driver.release(); this removes all buffers, regardless of their age, > freeing the buffers' associated resources (objects, adress space areas). > However there is other code that runs within the drm_driver.release() call > chain that expects objects and their associated address space areas have > already been flushed. > > Since buffer pools auto-flush old buffers once per second in a worker > thread, there's a small window where if we remove the driver while there > are still objects in buffers with an age of less than one second, the > assumptions of the other release code may be violated. > > By moving the flush to driver remove (which executes earlier via the > pci_driver.remove() flow) we're ensuring that all buffers are flushed and > their associated objects freed before some other code in > pci_driver.remove() flushes those objects so they are released before > _any_ code in drm_driver.release() that check completness of those > flushes executes. > > v2: Reword commit descriptiom as suggested by Matt. > > Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@xxxxxxxxxxxxxxx> > Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Matt Roper <matthew.d.roper@xxxxxxxxx> Reviewed-by: Matt Roper <matthew.d.roper@xxxxxxxxx> and applied to drm-intel-gt-next (with a couple minor spelling fixes in the commit message). Thanks for the patch. Matt > --- > drivers/gpu/drm/i915/gt/intel_gt.c | 2 ++ > drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c | 2 -- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c > index 4037c3778225..5b3acf2b064e 100644 > --- a/drivers/gpu/drm/i915/gt/intel_gt.c > +++ b/drivers/gpu/drm/i915/gt/intel_gt.c > @@ -741,6 +741,8 @@ void intel_gt_driver_remove(struct intel_gt *gt) > intel_uc_driver_remove(>->uc); > > intel_engines_release(gt); > + > + intel_gt_flush_buffer_pool(gt); > } > > void intel_gt_driver_unregister(struct intel_gt *gt) > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c b/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c > index aa0a59c5b614..acc49c56a9f3 100644 > --- a/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c > +++ b/drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c > @@ -245,8 +245,6 @@ void intel_gt_fini_buffer_pool(struct intel_gt *gt) > struct intel_gt_buffer_pool *pool = >->buffer_pool; > int n; > > - intel_gt_flush_buffer_pool(gt); > - > for (n = 0; n < ARRAY_SIZE(pool->cache_list); n++) > GEM_BUG_ON(!list_empty(&pool->cache_list[n])); > } > -- > 2.25.1 > -- Matt Roper Graphics Software Engineer VTT-OSGC Platform Enablement Intel Corporation (916) 356-2795
