Re: [RFC 16/44] drm/i915: Alloc early seqno

Jesse Barnes
2014-07-02T18:28:45Z

On Thu, 26 Jun 2014 18:24:07 +0100
John.C.Harrison@Intel.com wrote:

> From: John Harrison <John.C.Harrison@Intel.com>
>
> The scheduler needs to explicitly allocate a seqno to track each submitted batch
> buffer. This must happen a long time before any commands are actually written to
> the ring.
> ---
> drivers/gpu/drm/i915/i915_gem_execbuffer.c | 5 +++++
> drivers/gpu/drm/i915/intel_ringbuffer.c | 2 +-
> drivers/gpu/drm/i915/intel_ringbuffer.h | 1 +
> 3 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index ee836a6..ec274ef 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -1317,6 +1317,11 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
> vma->bind_vma(vma, batch_obj->cache_level, GLOBAL_BIND);
> }
>
> + /* Allocate a seqno for this batch buffer nice and early. */
> + ret = intel_ring_alloc_seqno(ring);
> + if (ret)
> + goto err;
> +
> if (flags & I915_DISPATCH_SECURE)
> exec_start += i915_gem_obj_ggtt_offset(batch_obj);
> else
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 34d6d6e..737c41b 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -1662,7 +1662,7 @@ int intel_ring_idle(struct intel_engine_cs *ring)
> return i915_wait_seqno(ring, seqno);
> }
>
> -static int
> +int
> intel_ring_alloc_seqno(struct intel_engine_cs *ring)
> {
> if (ring->outstanding_lazy_seqno)
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
> index 30841ea..cc92de2 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
> @@ -347,6 +347,7 @@ void intel_cleanup_ring_buffer(struct intel_engine_cs *ring);
>
> int __must_check intel_ring_begin(struct intel_engine_cs *ring, int n);
> int __must_check intel_ring_cacheline_align(struct intel_engine_cs *ring);
> +int __must_check intel_ring_alloc_seqno(struct intel_engine_cs *ring);
> static inline void intel_ring_emit(struct intel_engine_cs *ring,
> u32 data)
> {

This ought to be ok even w/o the scheduler, we'll just pick up the
lazy_seqno later on rather than allocating a new one at ring_begin
right?

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

--
Jesse Barnes, Intel Open Source Technology Center