[Intel-gfx] [PATCH v1] drm/i915/guc: Fix a memory leak where guc->execbuf_client is not freed
david.s.gordon at intel.com
Wed Jan 13 10:51:44 PST 2016
On 13/01/16 18:17, Yu Dai wrote:
> On 01/13/2016 10:15 AM, Dave Gordon wrote:
>> On 12/01/16 23:17, yu.dai at intel.com wrote:
>> > From: Alex Dai <yu.dai at intel.com>
>> > During driver unloading, the guc_client created for command submission
>> > needs to be released to avoid memory leak.
>> > The struct_mutex needs to be held before tearing down GuC.
>> > v1: Move i915_guc_submission_disable out of i915_guc_submission_fini
>> > take struct_mutex lock before release GuC client. (Dave Gordon)
>> You don't seem to have implemented all the points I mentioned? I think
>> you want:
>> @@ -445,6 +445,7 @@ int intel_guc_ucode_load(struct drm_device *dev)
>> + i915_guc_submission_fini(dev);
>> Optional, but cleaner. We called i915_guc_submission_init() earlier in
>> this function, so we should call i915_guc_submission_fini() in the
>> failure path. That way, we either succeed, or leave the system state
>> unchanged, NOT leaving extra objects allocated.
>> return err;
> I don't want this because struct_mutex is held by caller already while
> the fini() will acquire it too.
Yes it is and no it won't. That's guc_*submission*_fini() I want to call
(which requires the mutex held), not intel_guc_*ucode*_fini() (which, as
you say, acquires it).
>> @@ -561,10 +562,12 @@ static void guc_fw_fetch(struct drm_device *dev,
>> struct intel_guc_fw *guc_fw)
>> DRM_ERROR("Failed to fetch GuC firmware from %s (error %d)\n",
>> guc_fw->guc_fw_path, err);
>> + mutex_lock(&dev->struct_mutex);
>> obj = guc_fw->guc_fw_obj;
>> if (obj)
>> guc_fw->guc_fw_obj = NULL;
>> + mutex_unlock(&dev->struct_mutex);
>> This is the locking that needs to be added to the failure path.
>> This is required *in addition to* the locking reorganisation below.
> I missed this part.
>> > Signed-off-by: Alex Dai <yu.dai at intel.com>
>> > diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c
>> > index d20788f..70fa8f5 100644
>> > --- a/drivers/gpu/drm/i915/intel_guc_loader.c
>> > +++ b/drivers/gpu/drm/i915/intel_guc_loader.c
>> > @@ -631,10 +631,11 @@ void intel_guc_ucode_fini(struct drm_device *dev)
>> > struct drm_i915_private *dev_priv = dev->dev_private;
>> > struct intel_guc_fw *guc_fw = &dev_priv->guc.guc_fw;
>> > + mutex_lock(&dev->struct_mutex);
>> > direct_interrupts_to_host(dev_priv);
>> > + i915_guc_submission_disable(dev);
>> > i915_guc_submission_fini(dev);
>> > - mutex_lock(&dev->struct_mutex);
>> > if (guc_fw->guc_fw_obj)
>> > drm_gem_object_unreference(&guc_fw->guc_fw_obj->base);
>> > guc_fw->guc_fw_obj = NULL;
>> This bit is fine, but incomplete without the other changes above.
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