Patch "drm/sched: Always wake up correct scheduler in drm_sched_entity_push_job" has been added to the 6.10-stable tree

[Christian König]

Or wait a second with that.

Tvrtko which one was the patch we had to revert?

Regards,
Christian.

Am 07.10.24 um 19:53 schrieb Christian König:
> Hi Greg,
>
> please drop this patch from all backports. It turned out to be broken 
> and the old handling has been restored by a revert.
>
> Sorry for the noise. The revert should show up in Linus tree by the 
> end of the week.
>
> Regards,
> Christian.
>
> Am 07.10.24 um 19:50 schrieb gregkh at linuxfoundation.org:
>> This is a note to let you know that I've just added the patch titled
>>
>>      drm/sched: Always wake up correct scheduler in 
>> drm_sched_entity_push_job
>>
>> to the 6.10-stable tree which can be found at:
>> http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
>>
>> The filename of the patch is:
>> drm-sched-always-wake-up-correct-scheduler-in-drm_sched_entity_push_job.patch
>> and it can be found in the queue-6.10 subdirectory.
>>
>> If you, or anyone else, feels it should not be added to the stable tree,
>> please let <stable at vger.kernel.org> know about it.
>>
>>
>>  From cbc8764e29c2318229261a679b2aafd0f9072885 Mon Sep 17 00:00:00 2001
>> From: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
>> Date: Tue, 24 Sep 2024 11:19:08 +0100
>> Subject: drm/sched: Always wake up correct scheduler in 
>> drm_sched_entity_push_job
>> MIME-Version: 1.0
>> Content-Type: text/plain; charset=UTF-8
>> Content-Transfer-Encoding: 8bit
>>
>> From: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
>>
>> commit cbc8764e29c2318229261a679b2aafd0f9072885 upstream.
>>
>> Since drm_sched_entity_modify_sched() can modify the entities run queue,
>> lets make sure to only dereference the pointer once so both adding and
>> waking up are guaranteed to be consistent.
>>
>> Alternative of moving the spin_unlock to after the wake up would for now
>> be more problematic since the same lock is taken inside
>> drm_sched_rq_update_fifo().
>>
>> v2:
>>   * Improve commit message. (Philipp)
>>   * Cache the scheduler pointer directly. (Christian)
>>
>> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
>> Fixes: b37aced31eb0 ("drm/scheduler: implement a function to modify 
>> sched list")
>> Cc: Christian König <christian.koenig at amd.com>
>> Cc: Alex Deucher <alexander.deucher at amd.com>
>> Cc: Luben Tuikov <ltuikov89 at gmail.com>
>> Cc: Matthew Brost <matthew.brost at intel.com>
>> Cc: David Airlie <airlied at gmail.com>
>> Cc: Daniel Vetter <daniel at ffwll.ch>
>> Cc: Philipp Stanner <pstanner at redhat.com>
>> Cc: dri-devel at lists.freedesktop.org
>> Cc: <stable at vger.kernel.org> # v5.7+
>> Reviewed-by: Christian König <christian.koenig at amd.com>
>> Link: 
>> https://patchwork.freedesktop.org/patch/msgid/20240924101914.2713-3-tursulin@igalia.com
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
>> ---
>>   drivers/gpu/drm/scheduler/sched_entity.c |   10 ++++++++--
>>   1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> --- a/drivers/gpu/drm/scheduler/sched_entity.c
>> +++ b/drivers/gpu/drm/scheduler/sched_entity.c
>> @@ -599,6 +599,9 @@ void drm_sched_entity_push_job(struct dr
>>         /* first job wakes up scheduler */
>>       if (first) {
>> +        struct drm_gpu_scheduler *sched;
>> +        struct drm_sched_rq *rq;
>> +
>>           /* Add the entity to the run queue */
>>           spin_lock(&entity->rq_lock);
>>           if (entity->stopped) {
>> @@ -608,13 +611,16 @@ void drm_sched_entity_push_job(struct dr
>>               return;
>>           }
>>   -        drm_sched_rq_add_entity(entity->rq, entity);
>> +        rq = entity->rq;
>> +        sched = rq->sched;
>> +
>> +        drm_sched_rq_add_entity(rq, entity);
>>           spin_unlock(&entity->rq_lock);
>>             if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
>>               drm_sched_rq_update_fifo(entity, submit_ts);
>>   -        drm_sched_wakeup(entity->rq->sched);
>> +        drm_sched_wakeup(sched);
>>       }
>>   }
>>   EXPORT_SYMBOL(drm_sched_entity_push_job);
>>
>>
>> Patches currently in stable-queue which might be from 
>> tvrtko.ursulin at igalia.com are
>>
>> queue-6.10/drm-sched-always-increment-correct-scheduler-score.patch
>> queue-6.10/drm-v3d-prevent-out-of-bounds-access-in-performance-query-extensions.patch 
>>
>> queue-6.10/drm-sched-always-wake-up-correct-scheduler-in-drm_sched_entity_push_job.patch 
>>
>> queue-6.10/drm-sched-add-locking-to-drm_sched_entity_modify_sched.patch
>