On Fri, 27 Oct 2023 09:35:01 +0200 Christian König <christian.koenig@xxxxxxx> wrote: > Am 27.10.23 um 09:32 schrieb Boris Brezillon: > > On Fri, 27 Oct 2023 09:22:12 +0200 > > Christian König <christian.koenig@xxxxxxx> wrote: > > > >>> + > >>> + /** > >>> + * @update_job_credits: Called once the scheduler is considering this > >>> + * job for execution. > >>> + * > >>> + * Drivers may use this to update the job's submission credits, which is > >>> + * useful to e.g. deduct the number of native fences which have been > >>> + * signaled meanwhile. > >>> + * > >>> + * The callback must either return the new number of submission credits > >>> + * for the given job, or zero if no update is required. > >>> + * > >>> + * This callback is optional. > >>> + */ > >>> + u32 (*update_job_credits)(struct drm_sched_job *sched_job); > >> Why do we need an extra callback for this? > >> > >> Just document that prepare_job() is allowed to reduce the number of > >> credits the job might need. > > ->prepare_job() is called only once if the returned fence is NULL, but > > we need this credit-update to happen every time a job is considered for > > execution by the scheduler. > > But the job is only considered for execution once. How do you see that > this is called multiple times? Nope, it's not. If drm_sched_can_queue() returns false, the scheduler will go look for another entity that has a job ready for execution, and get back to this entity later, and test drm_sched_can_queue() again. Basically, any time drm_sched_can_queue() is called, the job credits update should happen, so we have an accurate view of how many credits this job needs.
