On Fri, May 05, 2017 at 02:30:08PM +0100, Tvrtko Ursulin wrote:
>
> On 03/05/2017 12:37, Chris Wilson wrote:
> >If we do not require to perform priority bumping, and we haven't yet
> >submitted the request, we can update its priority in situ and skip
> >acquiring the engine locks -- thus avoiding any contention between us
> >and submit/execute.
> >
> >Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> >---
> > drivers/gpu/drm/i915/intel_lrc.c | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> >diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> >index fb0025627676..ca7f28795e2d 100644
> >--- a/drivers/gpu/drm/i915/intel_lrc.c
> >+++ b/drivers/gpu/drm/i915/intel_lrc.c
> >@@ -767,6 +767,17 @@ static void execlists_schedule(struct drm_i915_gem_request *request, int prio)
> > list_safe_reset_next(dep, p, dfs_link);
> > }
> >
> >+ /* If we didn't need to bump any existing priorites, and we haven't
>
> priorities
>
> >+ * yet submitted this request (i..e there is no porential race with
>
> potential
>
> >+ * execlists_submit_request()), we can set our own priority and skip
> >+ * acquiring the engine locks.
> >+ */
> >+ if (request->priotree.priority == INT_MIN) {
> >+ request->priotree.priority = prio;
> >+ if (stack.dfs_link.next == stack.dfs_link.prev)
> >+ return;
>
> Move the assignment of the priority under the if?
The assignment always work. I just liked the look of this code more :)
The skip of the assignment is minor benefit. For bonus points, could do
a list_del_entry(&stack.dfs_link) after the return.
Sold.
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
