David any objections that I take this patch and make the necessary modifications?
People are pinging me about the problem. Regards, Christian. On 09.10.25 17:04, Christian König wrote: > FYI > > On 09.10.25 09:01, Christian König wrote: >> On 02.10.25 17:05, David Rosca wrote: >>> drm_sched_entity_flush should only kill the entity if the current >>> process is the last user of the entity. The last_user is only set >>> when adding new job, so entities that had no jobs submitted to them >>> have NULL last_user and would always be killed. >>> Another issue is setting last_user to NULL from drm_sched_entity_flush, >>> which causes subsequent calls to kill the entity. >>> >>> Signed-off-by: David Rosca <[email protected]> >>> Fixes: 51564e9f06f0 ("drm/amdgpu: Avoid extra evict-restore process.") >> >> Good catch, but in general please CC the relevant maintainers and mailing >> lists for scheduler patches. >> >>> --- >>> drivers/gpu/drm/scheduler/sched_entity.c | 5 ++--- >>> 1 file changed, 2 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/scheduler/sched_entity.c >>> b/drivers/gpu/drm/scheduler/sched_entity.c >>> index 8867b95ab089..a325e4a59990 100644 >>> --- a/drivers/gpu/drm/scheduler/sched_entity.c >>> +++ b/drivers/gpu/drm/scheduler/sched_entity.c >>> @@ -70,6 +70,7 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, >>> entity->guilty = guilty; >>> entity->num_sched_list = num_sched_list; >>> entity->priority = priority; >>> + entity->last_user = current->group_leader; >>> /* >>> * It's perfectly valid to initialize an entity without having a valid >>> * scheduler attached. It's just not valid to use the scheduler before >>> it >>> @@ -278,7 +279,6 @@ static void drm_sched_entity_kill(struct >>> drm_sched_entity *entity) >>> long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout) >>> { >>> struct drm_gpu_scheduler *sched; >>> - struct task_struct *last_user; >>> long ret = timeout; >>> >>> if (!entity->rq) >>> @@ -301,8 +301,7 @@ long drm_sched_entity_flush(struct drm_sched_entity >>> *entity, long timeout) >>> } >>> >>> /* For killed process disable any more IBs enqueue right now */ >>> - last_user = cmpxchg(&entity->last_user, current->group_leader, NULL); >>> - if ((!last_user || last_user == current->group_leader) && >>> + if (entity->last_user == current->group_leader && >> >> You still need the cmpxchg() here or otherwise drm_sched_entity_kill() would >> run multiple times. >> >> Regards, >> Christian. >> >>> (current->flags & PF_EXITING) && (current->exit_code == SIGKILL)) >>> drm_sched_entity_kill(entity); >>> >> >
