[Mesa-dev] [PATCH] r600: Use DMA transfers in r600_copy_global_buffer
Bruno Jimenez
brunojimen at gmail.com
Tue Sep 9 02:40:49 PDT 2014
On Mon, 2014-09-08 at 18:30 +0200, Niels Ole Salscheider wrote:
> On Monday 08 September 2014, 15:19:15, Bruno Jimenez wrote:
> > Hi,
> >
> > I'm not sure if this will work. Imagine this case:
> >
> > We have an item in the pool, and we want to use
> > r600_resource_copy_region with it, for example because we want to demote
> > it. This will call r600_copy_global_buffer, and with your patch it will
> > call r600_compute_global_demote_or_alloc, which will again call
> > compute_memory_demote_item causing an infinite cycle.
>
> I think this will not be a problem because neither the pool bo nor the
> "real_buffer" will have the PIPE_BIND_GLOBAL flag. Therefore,
> r600_compute_global_demote_or_alloc will not be called again.
>
Hi,
You are completely right, for a moment I thought that the resources
associated with the items also had the PIPE_BIND_GLOBAL flag.
Then I think that this code isn't truly necessary, as every call to
resource_copy_region related with compute items is done to the
r600_resources directly without touchin the global resources.
> > Also, why are you reassigning src and dst in r600_copy_global_buffer?
>
> For r600, resources with PIPE_BIND_GLOBAL are not real resources but only
> correspond to items in the compute pool. There they can either have the
> "real_buffer" bo when they should be mapped or be part of the pool bo.
> Therefore the pipe_resources have to be reassigned accordingly.
You are right again. I'm not thinking clearly lately, sorry.
>
> I am however not sure if it is really necessary to demote the item from the
> pool before copying data to it. Otherwise it would be possible to directly
> access the pool bo if the item is already in it.
I hope that it isn't necesary to demote the items for this. But, as I
have said, resource_copy_region isn't called with r600_resource_globals
(as far as I know)
Hopefully, I haven't said any other dumb thing.
Thanks!
Bruno
>
> > - Bruno
> >
> > On Sun, 2014-09-07 at 18:32 +0200, Niels Ole Salscheider wrote:
> > > Signed-off-by: Niels Ole Salscheider <niels_ole at salscheider-online.de>
> > > ---
> > >
> > > src/gallium/drivers/r600/evergreen_compute.c | 27 ++++++++++++-------
> > > src/gallium/drivers/r600/evergreen_compute.h | 1 +
> > > src/gallium/drivers/r600/r600_blit.c | 40
> > > ++++++++++++++++------------ 3 files changed, 41 insertions(+), 27
> > > deletions(-)
> > >
> > > diff --git a/src/gallium/drivers/r600/evergreen_compute.c
> > > b/src/gallium/drivers/r600/evergreen_compute.c index 38b78c7..b495868
> > > 100644
> > > --- a/src/gallium/drivers/r600/evergreen_compute.c
> > > +++ b/src/gallium/drivers/r600/evergreen_compute.c
> > > @@ -953,6 +953,22 @@ void r600_compute_global_buffer_destroy(
> > >
> > > free(res);
> > >
> > > }
> > >
> > > +void r600_compute_global_demote_or_alloc(
> > > + struct compute_memory_pool *pool,
> > > + struct compute_memory_item *item,
> > > + struct pipe_context *ctx)
> > > +{
> > > + if (is_item_in_pool(item)) {
> > > + compute_memory_demote_item(pool, item, ctx);
> > > + } else {
> > > + if (item->real_buffer == NULL) {
> > > + item->real_buffer = (struct r600_resource*)
> > > + r600_compute_buffer_alloc_vram(pool->screen, item-
> >size_in_dw * 4);
> > > + }
> > > + }
> > > +
> > > +}
> > > +
> > >
> > > void *r600_compute_global_transfer_map(
> > >
> > > struct pipe_context *ctx_,
> > > struct pipe_resource *resource,
> > >
> > > @@ -970,16 +986,7 @@ void *r600_compute_global_transfer_map(
> > >
> > > struct pipe_resource *dst = NULL;
> > > unsigned offset = box->x;
> > >
> > > - if (is_item_in_pool(item)) {
> > > - compute_memory_demote_item(pool, item, ctx_);
> > > - }
> > > - else {
> > > - if (item->real_buffer == NULL) {
> > > - item->real_buffer = (struct r600_resource*)
> > > - r600_compute_buffer_alloc_vram(pool->screen, item-
> >size_in_dw * 4);
> > > - }
> > > - }
> > > -
> > > + r600_compute_global_demote_or_alloc(pool, item, ctx_);
> > >
> > > dst = (struct pipe_resource*)item->real_buffer;
> > >
> > > if (usage & PIPE_TRANSFER_READ)
> > >
> > > diff --git a/src/gallium/drivers/r600/evergreen_compute.h
> > > b/src/gallium/drivers/r600/evergreen_compute.h index 4fb53a1..39bb854
> > > 100644
> > > --- a/src/gallium/drivers/r600/evergreen_compute.h
> > > +++ b/src/gallium/drivers/r600/evergreen_compute.h
> > > @@ -47,6 +47,7 @@ void evergreen_emit_cs_shader(struct r600_context *rctx,
> > > struct r600_atom * atom>
> > > struct pipe_resource *r600_compute_global_buffer_create(struct
> > > pipe_screen *screen, const struct pipe_resource *templ); void
> > > r600_compute_global_buffer_destroy(struct pipe_screen *screen, struct
> > > pipe_resource *res);>
> > > +void r600_compute_global_demote_or_alloc(struct compute_memory_pool
> > > *pool, struct compute_memory_item *item, struct pipe_context *ctx);>
> > > void *r600_compute_global_transfer_map(
> > >
> > > struct pipe_context *ctx_,
> > > struct pipe_resource *resource,
> > >
> > > diff --git a/src/gallium/drivers/r600/r600_blit.c
> > > b/src/gallium/drivers/r600/r600_blit.c index f766e37..f6471cb 100644
> > > --- a/src/gallium/drivers/r600/r600_blit.c
> > > +++ b/src/gallium/drivers/r600/r600_blit.c
> > > @@ -21,6 +21,8 @@
> > >
> > > * USE OR OTHER DEALINGS IN THE SOFTWARE.
> > > */
> > >
> > > #include "r600_pipe.h"
> > >
> > > +#include "compute_memory_pool.h"
> > > +#include "evergreen_compute.h"
> > >
> > > #include "util/u_surface.h"
> > > #include "util/u_format.h"
> > > #include "evergreend.h"
> > >
> > > @@ -514,29 +516,33 @@ static void r600_copy_buffer(struct pipe_context
> > > *ctx, struct pipe_resource *dst>
> > > * into a single global resource (r600_screen::global_pool). The means
> > > * they don't have their own cs_buf handle, so they cannot be passed
> > > * to r600_copy_buffer() and must be handled separately.
> > >
> > > - *
> > > - * XXX: It should be possible to implement this function using
> > > - * r600_copy_buffer() by passing the memory_pool resource as both src
> > > - * and dst and updating dstx and src_box to point to the correct offsets.
> > > - * This would likely perform better than the current implementation.
> > >
> > > */
> > >
> > > static void r600_copy_global_buffer(struct pipe_context *ctx,
> > >
> > > struct pipe_resource *dst, unsigned
> > > dstx, struct pipe_resource *src,
> > > const struct pipe_box *src_box)
> > >
> > > {
> > >
> > > - struct pipe_box dst_box; struct pipe_transfer *src_pxfer,
> > > - *dst_pxfer;
> > > -
> > > - u_box_1d(dstx, src_box->width, &dst_box);
> > > - void *src_ptr = ctx->transfer_map(ctx, src, 0, PIPE_TRANSFER_READ,
> > > - src_box, &src_pxfer);
> > > - void *dst_ptr = ctx->transfer_map(ctx, dst, 0, PIPE_TRANSFER_WRITE,
> > > - &dst_box, &dst_pxfer);
> > > - memcpy(dst_ptr, src_ptr, src_box->width);
> > > -
> > > - ctx->transfer_unmap(ctx, src_pxfer);
> > > - ctx->transfer_unmap(ctx, dst_pxfer);
> > > + struct r600_context *rctx = (struct r600_context*)ctx;
> > > + struct compute_memory_pool *pool = rctx->screen->global_pool;
> > > +
> > > + if (src->bind & PIPE_BIND_GLOBAL) {
> > > + struct r600_resource_global *rsrc =
> > > + (struct r600_resource_global *)src;
> > > + struct compute_memory_item *item = rsrc->chunk;
> > > +
> > > + r600_compute_global_demote_or_alloc(pool, item, ctx);
> > > + src = (struct pipe_resource*)item->real_buffer;
> > > + }
> > > + if (dst->bind & PIPE_BIND_GLOBAL) {
> > > + struct r600_resource_global *rdst =
> > > + (struct r600_resource_global *)dst;
> > > + struct compute_memory_item *item = rdst->chunk;
> > > +
> > > + r600_compute_global_demote_or_alloc(pool, item, ctx);
> > > + dst = (struct pipe_resource*)item->real_buffer;
> > > + }
> > > +
> > > + r600_copy_buffer(ctx, dst, dstx, src, src_box);
> > >
> > > }
> > >
> > > static void r600_clear_buffer(struct pipe_context *ctx, struct
> > > pipe_resource *dst,
>
More information about the mesa-dev
mailing list