fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2026-05-06 02:58:05 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

gallium/u_upload_mgr: lower risk of hitting an assert

Browse source 
The assert(size < INT32_MAX / 2) can be triggered by large uploads.

Since we know that the caller of u_upload_alloc_buffer will consume
min_size bytes, we can init buffer_private_refcount to a much smaller
value.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Fixes: ccf9ef3628 ("gallium/u_upload_mgr: eliminate all atomics for the upload buffer")
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/4235
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8880>
This commit is contained in:
Pierre-Eric Pelloux-Prayer 2021-02-05 15:31:19 +01:00
parent d81087a700
commit c7725ad4aa
1 changed files with 8 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
src/gallium/auxiliary/util/u_upload_mgr.c
View file

@ -227,10 +227,14 @@ u_upload_alloc_buffer(struct u_upload_mgr *upload, unsigned min_size)
* before the buffer is unreferenced.
*
* This technique can increase CPU performance by 10%.
*
* The caller of u_upload_alloc_buffer will consume min_size bytes,
* so init the buffer_private_refcount to 1 + size - min_size, instead
* of size to avoid overflowing reference.count when size is huge.
*/
assert(size < INT32_MAX / 2); /* prevent overflows of reference.count */
p_atomic_add(&upload->buffer->reference.count, size);
upload->buffer_private_refcount = size;
upload->buffer_private_refcount = 1 + (size - min_size);
assert(upload->buffer_private_refcount < INT32_MAX / 2);
p_atomic_add(&upload->buffer->reference.count, upload->buffer_private_refcount);
/* Map the new buffer. */
upload->map = pipe_buffer_map_range(upload->pipe, upload->buffer,
@ -304,6 +308,7 @@ u_upload_alloc(struct u_upload_mgr *upload,
if (*outbuf != upload->buffer) {
pipe_resource_reference(outbuf, NULL);
*outbuf = upload->buffer;
assert (upload->buffer_private_refcount > 0);
upload->buffer_private_refcount--;
}