From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
To: Jani Nikula <jani.nikula@linux.intel.com>,
Chris Wilson <chris@chris-wilson.co.uk>,
intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH 15/18] drm/i915: Reserve space in the global seqno during request allocation
Date: Mon, 19 Sep 2016 19:07:28 +0300 [thread overview]
Message-ID: <1474301248.3344.73.camel@linux.intel.com> (raw)
In-Reply-To: <877fa7zyuz.fsf@intel.com>
On ma, 2016-09-19 at 18:35 +0300, Jani Nikula wrote:
> > On Mon, 19 Sep 2016, Joonas Lahtinen <joonas.lahtinen@linux.intel.com> wrote:
> >
> > On ke, 2016-09-14 at 07:52 +0100, Chris Wilson wrote:
> > >
> > > +static int reserve_global_seqno(struct drm_i915_private *i915)
> > > {
> > > - struct i915_gem_timeline *tl = &dev_priv->gt.global_timeline;
> > > + struct i915_gem_timeline *tl = &i915->gt.global_timeline;
> > > + u32 next_seqno = atomic_read(&tl->next_seqno);
> > >
> > > - /* reserve 0 for non-seqno */
> > > - if (unlikely(tl->next_seqno == 0)) {
> >
> > Meh, do not hide the ++i915->gt.active_requests in if (unlikely(...)).
>
> *shudder* it doesn't get any better by removing unlikely!
>
Well, it gets twice as bad by adding it, though :P
My below recommendation would be preferred by lifting the increment
before the if ().
> > >
> > > + if (unlikely(next_seqno + ++i915->gt.active_requests <= next_seqno)) {
> > > int ret;
> > >
> >
> > Why not if (likely(next_seqno + active_requests > next_seqno))
> > > > return 0;
Regards, Joonas
--
Joonas Lahtinen
Open Source Technology Center
Intel Corporation
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next prev parent reply other threads:[~2016-09-19 16:07 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-14 6:52 Tracking multiple timelines (full-ppgtt) Chris Wilson
2016-09-14 6:52 ` [PATCH 01/18] drm/i915: Support asynchronous waits on struct fence from i915_gem_request Chris Wilson
2016-09-14 7:37 ` Joonas Lahtinen
2016-09-19 11:26 ` Chris Wilson
2016-09-14 6:52 ` [PATCH 02/18] drm/i915: Allow i915_sw_fence_await_sw_fence() to allocate Chris Wilson
2016-09-14 7:51 ` Joonas Lahtinen
2016-09-14 8:46 ` Chris Wilson
2016-09-14 6:52 ` [PATCH 03/18] drm/i915: Rearrange i915_wait_request() accounting with callers Chris Wilson
2016-09-14 8:47 ` Joonas Lahtinen
2016-09-14 6:52 ` [PATCH 04/18] drm/i915: Remove unused i915_gem_active_wait() in favour of _unlocked() Chris Wilson
2016-09-14 8:48 ` Joonas Lahtinen
2016-09-14 6:52 ` [PATCH 05/18] drm/i915: Move GEM activity tracking into a common struct reservation_object Chris Wilson
2016-09-14 9:44 ` Joonas Lahtinen
2016-09-14 17:35 ` Chris Wilson
2016-09-15 9:38 ` Dave Gordon
2016-09-15 9:55 ` Jani Nikula
2016-09-16 11:40 ` Chris Wilson
2016-09-14 6:52 ` [PATCH 06/18] drm: Add reference counting to drm_atomic_state Chris Wilson
2016-09-14 6:52 ` [PATCH 07/18] drm/i915: Restore nonblocking awaits for modesetting Chris Wilson
2016-09-19 16:01 ` Joonas Lahtinen
2016-09-14 6:52 ` [PATCH 08/18] drm/i915: Combine seqno + tracking into a global timeline struct Chris Wilson
2016-09-14 15:42 ` Joonas Lahtinen
2016-09-14 6:52 ` [PATCH 09/18] drm/i915: Wait first for submission, before waiting for request completion Chris Wilson
2016-09-19 8:59 ` Joonas Lahtinen
2016-09-14 6:52 ` [PATCH 10/18] drm/i915: Introduce a global_seqno for each request Chris Wilson
2016-09-19 10:36 ` Joonas Lahtinen
2016-09-14 6:52 ` [PATCH 11/18] drm/i915: Record space required for request emission Chris Wilson
2016-09-14 13:30 ` Tvrtko Ursulin
2016-09-14 17:33 ` Chris Wilson
2016-09-15 8:59 ` Tvrtko Ursulin
2016-09-19 10:47 ` Joonas Lahtinen
2016-09-19 11:32 ` Chris Wilson
2016-09-19 16:09 ` Joonas Lahtinen
2016-09-14 6:52 ` [PATCH 12/18] drm/i915: Defer " Chris Wilson
2016-09-19 12:06 ` Joonas Lahtinen
2016-09-14 6:52 ` [PATCH 13/18] drm/i915: Move the global sync optimisation to the timeline Chris Wilson
2016-09-19 13:16 ` Joonas Lahtinen
2016-09-14 6:52 ` [PATCH 14/18] drm/i915: Create a unique name for the context Chris Wilson
2016-09-19 13:23 ` Joonas Lahtinen
2016-09-14 6:52 ` [PATCH 15/18] drm/i915: Reserve space in the global seqno during request allocation Chris Wilson
2016-09-19 13:47 ` Joonas Lahtinen
2016-09-19 15:35 ` Jani Nikula
2016-09-19 16:07 ` Joonas Lahtinen [this message]
2016-09-14 6:52 ` [PATCH 16/18] drm/i915: Enable multiple timelines Chris Wilson
2016-09-19 15:52 ` Joonas Lahtinen
2016-10-20 12:49 ` Chris Wilson
2016-10-20 15:25 ` Joonas Lahtinen
2016-09-14 6:52 ` [PATCH 17/18] drm/i915: Enable userspace to opt-out of implicit fencing Chris Wilson
2016-09-14 6:52 ` [PATCH 18/18] drm/i915: Support explicit fencing for execbuf Chris Wilson
2016-09-14 9:16 ` ✗ Fi.CI.BAT: failure for series starting with [01/18] drm/i915: Support asynchronous waits on struct fence from i915_gem_request Patchwork
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