[PATCH 2/2] drm/xe/ufence: Warn if mmget_not_zero() fails

[Maarten Lankhorst]

I believe this is triggerable from userspace, so this should be a 
XE_IOCTL_DBG

Den 2024-10-14 kl. 11:27, skrev Francois Dugast:
> On Fri, Oct 11, 2024 at 01:57:15PM +0200, Nirmoy Das wrote:
>> This shouldn't happen but seen this while debugging ufence timeout
>> issue time to time so log it to isolate this particular case.
>>
>> Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/1630
>> Cc: Matthew Brost <matthew.brost at intel.com>
>> Signed-off-by: Nirmoy Das <nirmoy.das at intel.com>
> 
> Reviewed-by: Francois Dugast <francois.dugast at intel.com>
> 
>> ---
>>   drivers/gpu/drm/xe/xe_sync.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_sync.c b/drivers/gpu/drm/xe/xe_sync.c
>> index 6a2e4dd41d56..41758f528d7c 100644
>> --- a/drivers/gpu/drm/xe/xe_sync.c
>> +++ b/drivers/gpu/drm/xe/xe_sync.c
>> @@ -83,6 +83,8 @@ static void user_fence_worker(struct work_struct *w)
>>   			XE_WARN_ON("Copy to user failed");
>>   		kthread_unuse_mm(ufence->mm);
>>   		mmput(ufence->mm);
>> +	} else {
>> +		XE_WARN_ON("mmget_not_zero() failed");
>>   	}
>>   
>>   	wake_up_all(&ufence->xe->ufence_wq);
>> -- 
>> 2.46.0
>>