[Intel-gfx] [PATCH v2 1/2] i965: Cleanup MapRangeBuffer
Ben Widawsky
ben at bwidawsk.net
Tue Sep 27 07:49:46 CEST 2011
On Mon, Sep 26, 2011 at 09:40:12AM -0700, Eric Anholt wrote:
> On Sun, 25 Sep 2011 18:35:31 -0700, Ben Widawsky <ben at bwidawsk.net> wrote:
> > Clean the code up, and always use a BO when creating a new buffer. I've
> > not seen any regressions but haven't yet tried this on < Gen6.
> >
> > Cc: Chad Versace <chad at chad-versace.us>
> > Cc: Eric Anholt <eric at anholt.net>
> > Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> > ---
> > src/mesa/drivers/dri/intel/intel_buffer_objects.c | 114 ++++++++++-----------
> > src/mesa/drivers/dri/intel/intel_buffer_objects.h | 4 +-
> > 2 files changed, 55 insertions(+), 63 deletions(-)
> >
> > diff --git a/src/mesa/drivers/dri/intel/intel_buffer_objects.c b/src/mesa/drivers/dri/intel/intel_buffer_objects.c
> > index 4df2d76..78e3468 100644
> > --- a/src/mesa/drivers/dri/intel/intel_buffer_objects.c
> > +++ b/src/mesa/drivers/dri/intel/intel_buffer_objects.c
> > @@ -291,6 +291,19 @@ intel_bufferobj_map_range(struct gl_context * ctx,
> >
> > assert(intel_obj);
> >
> > + /* Catch some errors early to make real logic a bit easier */
> > + if ((access & (GL_MAP_FLUSH_EXPLICIT_BIT | GL_MAP_WRITE_BIT)) ==
> > + GL_MAP_INVALIDATE_RANGE_BIT)
> > + goto error_out;
> > +
> > + if ((access & (GL_MAP_INVALIDATE_RANGE_BIT | GL_MAP_READ_BIT)) ==
> > + (GL_MAP_INVALIDATE_RANGE_BIT|GL_MAP_READ_BIT))
> > + goto error_out;
> > +
> > + if ((access & (GL_MAP_INVALIDATE_BUFFER_BIT | GL_MAP_READ_BIT)) ==
> > + (GL_MAP_INVALIDATE_BUFFER_BIT | GL_MAP_READ_BIT))
> > + goto error_out;
> > +
>
> Why are you introducing broken error checks for things that are already
> correctly checked in Mesa core?
While I agree this shouldn't be there if Mesa core does it, I argue that
the checks are broken (they aren't comprehensive). Anyway, I'm convinced
it does work correctly in Mesa core because of Yuanhan's tests, but I'll
be damned if I can find the code that does it.
>
> > /* If the user doesn't care about existing buffer contents and mapping
> > * would cause us to block, then throw out the old buffer.
> > */
> > @@ -344,36 +355,30 @@ intel_bufferobj_map_range(struct gl_context * ctx,
> > */
> > if ((access & GL_MAP_INVALIDATE_RANGE_BIT) &&
> > drm_intel_bo_busy(intel_obj->buffer)) {
> > - if (access & GL_MAP_FLUSH_EXPLICIT_BIT) {
> > - intel_obj->range_map_buffer = malloc(length);
> > - obj->Pointer = intel_obj->range_map_buffer;
> > - } else {
> > - intel_obj->range_map_bo = drm_intel_bo_alloc(intel->bufmgr,
> > - "range map",
> > - length, 64);
> > - if (!(access & GL_MAP_READ_BIT)) {
> > - drm_intel_gem_bo_map_gtt(intel_obj->range_map_bo);
> > - intel_obj->mapped_gtt = GL_TRUE;
> > - } else {
> > - drm_intel_bo_map(intel_obj->range_map_bo,
> > - (access & GL_MAP_WRITE_BIT) != 0);
> > - intel_obj->mapped_gtt = GL_FALSE;
> > - }
> > - obj->Pointer = intel_obj->range_map_bo->virtual;
> > - }
> > - return obj->Pointer;
> > - }
> > -
> > - if (!(access & GL_MAP_READ_BIT)) {
> > + intel_obj->range_map_bo = drm_intel_bo_alloc(intel->bufmgr,
> > + "range map",
> > + length, 64);
> > + drm_intel_gem_bo_map_gtt(intel_obj->range_map_bo);
> > + intel_obj->mapped_gtt = true;
> > + obj->Pointer = intel_obj->range_map_bo->virtual;
> > + } else if (!(access & GL_MAP_READ_BIT)) { /* Write only */
> > drm_intel_gem_bo_map_gtt(intel_obj->buffer);
> > - intel_obj->mapped_gtt = GL_TRUE;
> > - } else {
> > + intel_obj->mapped_gtt = true;
> > + obj->Pointer = intel_obj->buffer->virtual + offset;
> > + } else { /* R/W or RO */
> > drm_intel_bo_map(intel_obj->buffer, (access & GL_MAP_WRITE_BIT) != 0);
> > - intel_obj->mapped_gtt = GL_FALSE;
> > + intel_obj->mapped_gtt = false;
> > + obj->Pointer = intel_obj->buffer->virtual + offset;
> > }
> >
> > - obj->Pointer = intel_obj->buffer->virtual + offset;
> > + if (!(access & GL_MAP_FLUSH_EXPLICIT_BIT))
> > + intel_obj->needs_flush_at_unmap = true;
> > +
> > return obj->Pointer;
> > +
> > +error_out:
> > + obj->Pointer = NULL;
> > + return NULL;
> > }
> >
> > /* Ideally we'd use a BO to avoid taking up cache space for the temporary
> > @@ -388,27 +393,22 @@ intel_bufferobj_flush_mapped_range(struct gl_context *ctx,
> > {
> > struct intel_context *intel = intel_context(ctx);
> > struct intel_buffer_object *intel_obj = intel_buffer_object(obj);
> > - drm_intel_bo *temp_bo;
> >
> > - /* Unless we're in the range map using a temporary system buffer,
> > - * there's no work to do.
> > - */
> > - if (intel_obj->range_map_buffer == NULL)
> > - return;
> > + assert(intel_obj->needs_flush_at_unmap == false);
> >
> > if (length == 0)
> > return;
> >
> > - temp_bo = drm_intel_bo_alloc(intel->bufmgr, "range map flush", length, 64);
> > -
> > - drm_intel_bo_subdata(temp_bo, 0, length, intel_obj->range_map_buffer);
> > -
> > - intel_emit_linear_blit(intel,
> > - intel_obj->buffer, obj->Offset + offset,
> > - temp_bo, 0,
> > - length);
> > + if (!intel_obj->range_map_bo) {
> > + intel_batchbuffer_emit_mi_flush(intel);
> > + } else {
> > + intel_emit_linear_blit(intel,
> > + intel_obj->buffer, obj->Offset + offset,
> > + intel_obj->range_map_bo, 0,
> > + length);
> >
> > - drm_intel_bo_unreference(temp_bo);
> > + drm_intel_bo_unreference(intel_obj->range_map_bo);
> > + }
> > }
> >
> >
> > @@ -425,15 +425,6 @@ intel_bufferobj_unmap(struct gl_context * ctx, struct gl_buffer_object *obj)
> > assert(obj->Pointer);
> > if (intel_obj->sys_buffer != NULL) {
> > /* always keep the mapping around. */
> > - } else if (intel_obj->range_map_buffer != NULL) {
> > - /* Since we've emitted some blits to buffers that will (likely) be used
> > - * in rendering operations in other cache domains in this batch, emit a
> > - * flush. Once again, we wish for a domain tracker in libdrm to cover
> > - * usage inside of a batchbuffer.
> > - */
> > - intel_batchbuffer_emit_mi_flush(intel);
> > - free(intel_obj->range_map_buffer);
> > - intel_obj->range_map_buffer = NULL;
> > } else if (intel_obj->range_map_bo != NULL) {
> > if (intel_obj->mapped_gtt) {
> > drm_intel_gem_bo_unmap_gtt(intel_obj->range_map_bo);
> > @@ -441,10 +432,13 @@ intel_bufferobj_unmap(struct gl_context * ctx, struct gl_buffer_object *obj)
> > drm_intel_bo_unmap(intel_obj->range_map_bo);
> > }
> >
> > - intel_emit_linear_blit(intel,
> > - intel_obj->buffer, obj->Offset,
> > - intel_obj->range_map_bo, 0,
> > - obj->Length);
> > + if (intel_obj->needs_flush_at_unmap) {
> > + intel_emit_linear_blit(intel,
> > + intel_obj->buffer, obj->Offset,
> > + intel_obj->range_map_bo, 0,
> > + obj->Length);
> > + drm_intel_bo_unreference(intel_obj->range_map_bo);
> > + }
> >
> > /* Since we've emitted some blits to buffers that will (likely) be used
> > * in rendering operations in other cache domains in this batch, emit a
> > @@ -452,8 +446,6 @@ intel_bufferobj_unmap(struct gl_context * ctx, struct gl_buffer_object *obj)
> > * usage inside of a batchbuffer.
> > */
> > intel_batchbuffer_emit_mi_flush(intel);
>
> If you have this flush here, you don't need it in the explicit range
> flushes where you added it.
This belonged in the if condition right above, we only need to flush if
needs_flush_at_unmap is set.
How do you feel about the patch otherwise?
Ben
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