radeon/winsys: Limit max allocation size to 70% of VRAM

The CL CTS queries the max allocation size, and then attempts to
allocate buffers of that size. If not enough contiguous RAM/VRAM is
available, this causes errors in the radeon kernel module due to
inability to allocate the required memory.

It's a bit of a hack, but experimentally on my system, I can use ~3/4
of the card's VRAM for a single global/constant buffer allocation given
current GUI/compositor use.

For a 1GB Pitcairn (HD7850) this gets me from the reported clinfo values of:
Global memory size                              2143076352 (1.996GiB)
Max memory allocation                           1500153446 (1.397GiB)
Max constant buffer size                        1500153446 (1.397GiB)

To:
Global memory size                              2143076352 (1.996GiB)
Max memory allocation                           751619276 (716MiB)
Max constant buffer size                        751619276 (716MiB)

Fixes: OpenCL CTS test/conformance/api/min_max_mem_alloc_size,
       OpenCL CTS test/conformance/api/min_max_constant_buffer_size

Signed-off-by: Aaron Watry <awatry@gmail.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
This commit is contained in:
Aaron Watry
2017-06-09 12:57:42 -05:00
parent b6d56c747c
commit e4d06e4c53

View File

@@ -365,6 +365,8 @@ static bool do_winsys_init(struct radeon_drm_winsys *ws)
/* Radeon allocates all buffers as contigous, which makes large allocations
* unlikely to succeed. */
ws->info.max_alloc_size = MAX2(ws->info.vram_size, ws->info.gart_size) * 0.7;
if (ws->info.has_dedicated_vram)
ws->info.max_alloc_size = MIN2(ws->info.vram_size * 0.7, ws->info.max_alloc_size);
if (ws->info.drm_minor < 40)
ws->info.max_alloc_size = MIN2(ws->info.max_alloc_size, 256*1024*1024);