Re: [PATCH 7/7] drm/lima: Use the drm_gem_fence_array_add helpers for our deps.

From: Qiang Yu
Date: Tue Apr 02 2019 - 20:55:25 EST


Indeed not that important, so patch 5&7 is:
Reviewed-and-tested-by: Qiang Yu <yuq825@xxxxxxxxx>

Regards,
Qiang

On Wed, Apr 3, 2019 at 12:57 AM Eric Anholt <eric@xxxxxxxxxx> wrote:
>
> Qiang Yu <yuq825@xxxxxxxxx> writes:
>
> > On Tue, Apr 2, 2019 at 6:26 AM Eric Anholt <eric@xxxxxxxxxx> wrote:
> >>
> >> I haven't tested this, but it's a pretty direct port of what I did for
> >> v3d.
> >>
> >> Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
> >> ---
> >> drivers/gpu/drm/lima/lima_gem.c | 37 +----------------
> >> drivers/gpu/drm/lima/lima_sched.c | 66 ++++++-------------------------
> >> drivers/gpu/drm/lima/lima_sched.h | 6 +--
> >> 3 files changed, 16 insertions(+), 93 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c
> >> index 2d3cf96f6c58..8f80286c80b4 100644
> >> --- a/drivers/gpu/drm/lima/lima_gem.c
> >> +++ b/drivers/gpu/drm/lima/lima_gem.c
> >> @@ -144,40 +144,7 @@ static int lima_gem_sync_bo(struct lima_sched_task *task, struct lima_bo *bo,
> >> if (explicit)
> >> return 0;
> >>
> >> - /* implicit sync use bo fence in resv obj */
> >> - if (write) {
> >> - unsigned nr_fences;
> >> - struct dma_fence **fences;
> >> - int i;
> >> -
> >> - err = reservation_object_get_fences_rcu(
> >> - bo->gem.resv, NULL, &nr_fences, &fences);
> >> - if (err || !nr_fences)
> >> - return err;
> >> -
> >> - for (i = 0; i < nr_fences; i++) {
> >> - err = lima_sched_task_add_dep(task, fences[i]);
> >> - if (err)
> >> - break;
> >> - }
> >> -
> >> - /* for error case free remaining fences */
> >> - for ( ; i < nr_fences; i++)
> >> - dma_fence_put(fences[i]);
> >> -
> >> - kfree(fences);
> >> - } else {
> >> - struct dma_fence *fence;
> >> -
> >> - fence = reservation_object_get_excl_rcu(bo->gem.resv);
> >> - if (fence) {
> >> - err = lima_sched_task_add_dep(task, fence);
> >> - if (err)
> >> - dma_fence_put(fence);
> >> - }
> >> - }
> >> -
> >> - return err;
> >> + return drm_gem_fence_array_add_implicit(&task->deps, &bo->gem, write);
> >> }
> >>
> >> static int lima_gem_lock_bos(struct lima_bo **bos, u32 nr_bos,
> >> @@ -250,7 +217,7 @@ static int lima_gem_add_deps(struct drm_file *file, struct lima_submit *submit)
> >> if (err)
> >> return err;
> >>
> >> - err = lima_sched_task_add_dep(submit->task, fence);
> >> + err = drm_gem_fence_array_add(&submit->task->deps, fence);
> >> if (err) {
> >> dma_fence_put(fence);
> >> return err;
> >> diff --git a/drivers/gpu/drm/lima/lima_sched.c b/drivers/gpu/drm/lima/lima_sched.c
> >> index 97bd9c1deb87..e253d031fb3d 100644
> >> --- a/drivers/gpu/drm/lima/lima_sched.c
> >> +++ b/drivers/gpu/drm/lima/lima_sched.c
> >> @@ -3,6 +3,7 @@
> >>
> >> #include <linux/kthread.h>
> >> #include <linux/slab.h>
> >> +#include <linux/xarray.h>
> >>
> >> #include "lima_drv.h"
> >> #include "lima_sched.h"
> >> @@ -126,19 +127,24 @@ int lima_sched_task_init(struct lima_sched_task *task,
> >>
> >> task->num_bos = num_bos;
> >> task->vm = lima_vm_get(vm);
> >> +
> >> + xa_init_flags(&task->deps, XA_FLAGS_ALLOC);
> >> +
> >> return 0;
> >> }
> >>
> >> void lima_sched_task_fini(struct lima_sched_task *task)
> >> {
> >> + struct dma_fence *fence;
> >> + unsigned long index;
> >> int i;
> >>
> >> drm_sched_job_cleanup(&task->base);
> >>
> >> - for (i = 0; i < task->num_dep; i++)
> >> - dma_fence_put(task->dep[i]);
> >> -
> >> - kfree(task->dep);
> >> + xa_for_each(&task->deps, index, fence) {
> >> + dma_fence_put(fence);
> >> + }
> >> + xa_destroy(&task->deps);
> >>
> >> if (task->bos) {
> >> for (i = 0; i < task->num_bos; i++)
> >> @@ -149,42 +155,6 @@ void lima_sched_task_fini(struct lima_sched_task *task)
> >> lima_vm_put(task->vm);
> >> }
> >>
> >> -int lima_sched_task_add_dep(struct lima_sched_task *task, struct dma_fence *fence)
> >> -{
> >> - int i, new_dep = 4;
> >> -
> >> - /* same context's fence is definitly earlier then this task */
> >> - if (fence->context == task->base.s_fence->finished.context) {
> >> - dma_fence_put(fence);
> >> - return 0;
> >> - }
> >
> > Seems you dropped this check in the drm_gem_fence_array_add, no bug if we
> > don't have this, but redundant fence will be added in the deps array. Maybe we
> > can add a context parameter to drm_gem_fence_array_add and
> > drm_gem_fence_array_add_implicit to filter out fences from same
> > drm_sched_entity.
>
> Does this feel important to you? To me, one extra slot in the array and
> a trip through the top of drm_sched_entity_add_dependency_cb() doesn't
> like it's feel worth making the API clumsier.