Re: [PATCH v3 4/5] drm/sched: Use drm sched lockdep map for submit_wq

[Ghimiray, Himal Prasad]

On 14-08-2024 00:46, Matthew Brost wrote:
> On Mon, Aug 12, 2024 at 11:05:31AM +0530, Ghimiray, Himal Prasad wrote:
> > On 10-08-2024 03:58, Matthew Brost wrote:
> > > Avoid leaking a lockdep map on each drm sched creation and destruction
> > > by using a single lockdep map for all drm sched allocated submit_wq.
> > >
> > > v2:
> > >    - Use alloc_ordered_workqueue_lockdep_map (Tejun)
> > >
> > > Cc: Luben Tuikov <ltuikov89@xxxxxxxxx>
> > > Cc: Christian König <christian.koenig@xxxxxxx>
> > > Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
> > > ---
> > >    drivers/gpu/drm/scheduler/sched_main.c | 11 +++++++++++
> > >    1 file changed, 11 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> > > index ab53ab486fe6..cf79d348cb32 100644
> > > --- a/drivers/gpu/drm/scheduler/sched_main.c
> > > +++ b/drivers/gpu/drm/scheduler/sched_main.c
> > > @@ -87,6 +87,12 @@
> > >    #define CREATE_TRACE_POINTS
> > >    #include "gpu_scheduler_trace.h"
> > > +#ifdef CONFIG_LOCKDEP
> > > +static struct lockdep_map drm_sched_lockdep_map = {
> > > +	.name = "drm_sched_lockdep_map"
> > > +};
> >
> >
> > will it be better to use STATIC_LOCKDEP_MAP_INIT ? Initializing key here
> > instead of while registering the class ?
>
> Most existing design patterns in the kernel define static lockdep class
> this way so I think this is fine. But honestly don't really have an
> opinion here.
>
> Matt

In that case, I have no concerns with the current initialization.


> > > +#endif
> > > +
> > >    #define to_drm_sched_job(sched_job)		\
> > >    		container_of((sched_job), struct drm_sched_job, queue_node)
> > > @@ -1272,7 +1278,12 @@ int drm_sched_init(struct drm_gpu_scheduler *sched,
> > >    		sched->submit_wq = submit_wq;
> > >    		sched->own_submit_wq = false;
> > >    	} else {
> > > +#ifdef CONFIG_LOCKDEP
> > > +		sched->submit_wq = alloc_ordered_workqueue_lockdep_map(name, 0,
> > > +								       &drm_sched_lockdep_map);
> > > +#else
> > >    		sched->submit_wq = alloc_ordered_workqueue(name, 0);
> > > +#endif
> > >    		if (!sched->submit_wq)
> > >    			return -ENOMEM;