| Message ID | 20240828094133.17402-4-pstanner@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/2] drm/sched: memset() 'job' in drm_sched_job_init() | expand |
On 28/08/2024 10:41, Philipp Stanner wrote: > drm_sched_job_init()'s name suggests that after the function succeeded, > parameter "job" will be fully initialized. This is not the case; some > members are only later set, notably "job->sched" by drm_sched_job_arm(). > > Document that drm_sched_job_init() does not set all struct members. > > Document that job->sched in particular is uninitialized before > drm_sched_job_arm(). > > Signed-off-by: Philipp Stanner <pstanner@redhat.com> > --- > Changes in v2: > - Change grammar in the new comments a bit. > --- > drivers/gpu/drm/scheduler/sched_main.c | 4 ++++ > include/drm/gpu_scheduler.h | 7 +++++++ > 2 files changed, 11 insertions(+) > > diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c > index b0c8ad10b419..721373938c1e 100644 > --- a/drivers/gpu/drm/scheduler/sched_main.c > +++ b/drivers/gpu/drm/scheduler/sched_main.c > @@ -781,6 +781,10 @@ EXPORT_SYMBOL(drm_sched_resubmit_jobs); > * Drivers must make sure drm_sched_job_cleanup() if this function returns > * successfully, even when @job is aborted before drm_sched_job_arm() is called. > * > + * Note that this function does not assign a valid value to each struct member > + * of struct drm_sched_job. Take a look at that struct's documentation to see > + * who sets which struct member with what lifetime. First sentence is fine, but the second I don't see the those details in struct drm_sched_job. (And I am not saying that they must be listed. IMO at some point it is better to have a high level overview than describe the lifetime rules with individual members.) > + * > * WARNING: amdgpu abuses &drm_sched.ready to signal when the hardware > * has died, which can mean that there's no valid runqueue for a @entity. > * This function returns -ENOENT in this case (which probably should be -EIO as > diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h > index 5acc64954a88..04a268cd22f1 100644 > --- a/include/drm/gpu_scheduler.h > +++ b/include/drm/gpu_scheduler.h > @@ -337,6 +337,13 @@ struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f); > struct drm_sched_job { > struct spsc_node queue_node; > struct list_head list; > + > + /* > + * The scheduler this job is or will be scheduled on. > + * > + * Gets set by drm_sched_arm(). Valid until the scheduler's backend_ops > + * callback "free_job()" has been called. This is interesting - I was not sure where lifetime for job->sched is defined and couldn't find it browsing around. Where did you find the clues to tie it to the free_job() callback? Regards, Tvrtko > + */ > struct drm_gpu_scheduler *sched; > struct drm_sched_fence *s_fence; >
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index b0c8ad10b419..721373938c1e 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -781,6 +781,10 @@ EXPORT_SYMBOL(drm_sched_resubmit_jobs); * Drivers must make sure drm_sched_job_cleanup() if this function returns * successfully, even when @job is aborted before drm_sched_job_arm() is called. * + * Note that this function does not assign a valid value to each struct member + * of struct drm_sched_job. Take a look at that struct's documentation to see + * who sets which struct member with what lifetime. + * * WARNING: amdgpu abuses &drm_sched.ready to signal when the hardware * has died, which can mean that there's no valid runqueue for a @entity. * This function returns -ENOENT in this case (which probably should be -EIO as diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index 5acc64954a88..04a268cd22f1 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -337,6 +337,13 @@ struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f); struct drm_sched_job { struct spsc_node queue_node; struct list_head list; + + /* + * The scheduler this job is or will be scheduled on. + * + * Gets set by drm_sched_arm(). Valid until the scheduler's backend_ops + * callback "free_job()" has been called. + */ struct drm_gpu_scheduler *sched; struct drm_sched_fence *s_fence;
drm_sched_job_init()'s name suggests that after the function succeeded, parameter "job" will be fully initialized. This is not the case; some members are only later set, notably "job->sched" by drm_sched_job_arm(). Document that drm_sched_job_init() does not set all struct members. Document that job->sched in particular is uninitialized before drm_sched_job_arm(). Signed-off-by: Philipp Stanner <pstanner@redhat.com> --- Changes in v2: - Change grammar in the new comments a bit. --- drivers/gpu/drm/scheduler/sched_main.c | 4 ++++ include/drm/gpu_scheduler.h | 7 +++++++ 2 files changed, 11 insertions(+)