On Friday, September 26, 2014 09:22:31 AM Kristian Høgsberg wrote:
> On Fri, Aug 29, 2014 at 11:10:50PM -0700, Kenneth Graunke wrote:
> > There's no reason to stall on pwrite - the CPU always appends to the
> > buffer and never modifies existing contents, and the GPU never writes
> > it. Further, the CPU always appends new data before submitting a batch
> > that requires it.
> >
> > This code predates the unsynchronized mapping feature, so we simply
> > didn't have the option when it was written.
> >
> > Ideally, we would do this for non-LLC platforms too, but unsynchronized
> > mapping support only exists for LLC systems.
> >
> > Saves repeated 0.001ms stalls on program upload.
> >
> > Signed-off-by: Kenneth Graunke <kenn...@whitecape.org>
> > ---
> > src/mesa/drivers/dri/i965/brw_state_cache.c | 34
> > +++++++++++++++++++++++------
> > 1 file changed, 27 insertions(+), 7 deletions(-)
> >
> > diff --git a/src/mesa/drivers/dri/i965/brw_state_cache.c
> > b/src/mesa/drivers/dri/i965/brw_state_cache.c
> > index b9bb0fc..1d2d32f 100644
> > --- a/src/mesa/drivers/dri/i965/brw_state_cache.c
> > +++ b/src/mesa/drivers/dri/i965/brw_state_cache.c
> > @@ -172,14 +172,23 @@ brw_cache_new_bo(struct brw_cache *cache, uint32_t
> > new_size)
> > drm_intel_bo *new_bo;
> >
> > new_bo = drm_intel_bo_alloc(brw->bufmgr, "program cache", new_size, 64);
> > + if (brw->has_llc)
> > + drm_intel_gem_bo_map_unsynchronized(new_bo);
> >
> > /* Copy any existing data that needs to be saved. */
> > if (cache->next_offset != 0) {
> > - brw_bo_map(brw, cache->bo, false, "program cache");
> > - drm_intel_bo_subdata(new_bo, 0, cache->next_offset,
> > cache->bo->virtual);
> > - drm_intel_bo_unmap(cache->bo);
> > + if (brw->has_llc) {
> > + memcpy(new_bo->virtual, cache->bo->virtual, cache->next_offset);
>
> Move the drm_intel_gem_bo_map_unsynchronized() and drm_intel_bo_unmap()
> calls into this block so they bracket the memcpy as for the subdata case
> below?
>
> Other than that,
>
> Reviewed-by: Kristian Høgsberg <k...@bitplanet.net>
That won't work---the point is to map new_bo, and leave it mapped...and unmap
the old BO before throwing it away. If I moved the map call into the if
(cache->next_offset != 0) block, then the initial mapping would never occur.
> > + } else {
> > + brw_bo_map(brw, cache->bo, false, "program cache");
> > + drm_intel_bo_subdata(new_bo, 0, cache->next_offset,
> > + cache->bo->virtual);
> > + drm_intel_bo_unmap(cache->bo);
> > + }
> > }
> >
> > + if (brw->has_llc)
> > + drm_intel_bo_unmap(cache->bo);
> > drm_intel_bo_unreference(cache->bo);
> > cache->bo = new_bo;
> > cache->bo_used_by_gpu = false;
> > @@ -222,9 +231,11 @@ brw_try_upload_using_copy(struct brw_cache *cache,
> > continue;
> > }
> >
> > - brw_bo_map(brw, cache->bo, false, "program cache");
> > + if (!brw->has_llc)
> > + brw_bo_map(brw, cache->bo, false, "program cache");
> > ret = memcmp(cache->bo->virtual + item->offset, data, item->size);
> > - drm_intel_bo_unmap(cache->bo);
> > + if (!brw->has_llc)
> > + drm_intel_bo_unmap(cache->bo);
> > if (ret)
> > continue;
> >
> > @@ -257,7 +268,7 @@ brw_upload_item_data(struct brw_cache *cache,
> > /* If we would block on writing to an in-use program BO, just
> > * recreate it.
> > */
> > - if (cache->bo_used_by_gpu) {
> > + if (!brw->has_llc && cache->bo_used_by_gpu) {
> > perf_debug("Copying busy program cache buffer.\n");
> > brw_cache_new_bo(cache, cache->bo->size);
> > }
> > @@ -280,6 +291,7 @@ brw_upload_cache(struct brw_cache *cache,
> > uint32_t *out_offset,
> > void *out_aux)
> > {
> > + struct brw_context *brw = cache->brw;
> > struct brw_cache_item *item = CALLOC_STRUCT(brw_cache_item);
> > GLuint hash;
> > void *tmp;
> > @@ -320,7 +332,11 @@ brw_upload_cache(struct brw_cache *cache,
> > cache->n_items++;
> >
> > /* Copy data to the buffer */
> > - drm_intel_bo_subdata(cache->bo, item->offset, data_size, data);
> > + if (brw->has_llc) {
> > + memcpy((char *) cache->bo->virtual + item->offset, data, data_size);
> > + } else {
> > + drm_intel_bo_subdata(cache->bo, item->offset, data_size, data);
> > + }
> >
> > *out_offset = item->offset;
> > *(void **)out_aux = (void *)((char *)item->key + item->key_size);
> > @@ -342,6 +358,8 @@ brw_init_caches(struct brw_context *brw)
> > cache->bo = drm_intel_bo_alloc(brw->bufmgr,
> > "program cache",
> > 4096, 64);
> > + if (brw->has_llc)
> > + drm_intel_gem_bo_map_unsynchronized(cache->bo);
> >
> > cache->aux_compare[BRW_VS_PROG] = brw_vs_prog_data_compare;
> > cache->aux_compare[BRW_GS_PROG] = brw_gs_prog_data_compare;
> > @@ -408,6 +426,8 @@ brw_destroy_cache(struct brw_context *brw, struct
> > brw_cache *cache)
> >
> > DBG("%s\n", __FUNCTION__);
> >
> > + if (brw->has_llc)
> > + drm_intel_bo_unmap(cache->bo);
> > drm_intel_bo_unreference(cache->bo);
> > cache->bo = NULL;
> > brw_clear_cache(brw, cache);
>
signature.asc
Description: This is a digitally signed message part.
_______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
