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i965: Hard code CS scratch_ids_per_subslice for Cherryview 

Ken suggested that we might be underallocating scratch space on HD
400. Allocating scratch space as though there was actually 8 EUs
seems to help with a GPU hang seen on synmark CSDof.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104636
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105290
Cc: <mesa-stable@lists.freedesktop.org>
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Tested-by: Eero Tamminen <eero.t.tamminen@intel.com>
This commit is contained in:
Jordan Justen 2018-03-06 08:35:50 -08:00
parent db495b8962
commit 06e3bd02c0
1 changed files with 27 additions and 17 deletions
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44
src/mesa/drivers/dri/i965/brw_program.c
View File

@ -402,23 +402,33 @@ brw_alloc_stage_scratch(struct brw_context *brw,
if (devinfo->gen >= 9)
subslices = 4 * brw->screen->devinfo.num_slices;
/* WaCSScratchSize:hsw
*
* Haswell's scratch space address calculation appears to be sparse
* rather than tightly packed. The Thread ID has bits indicating
* which subslice, EU within a subslice, and thread within an EU
* it is. There's a maximum of two slices and two subslices, so these
* can be stored with a single bit. Even though there are only 10 EUs
* per subslice, this is stored in 4 bits, so there's an effective
* maximum value of 16 EUs. Similarly, although there are only 7
* threads per EU, this is stored in a 3 bit number, giving an effective
* maximum value of 8 threads per EU.
*
* This means that we need to use 16 * 8 instead of 10 * 7 for the
* number of threads per subslice.
*/
const unsigned scratch_ids_per_subslice =
devinfo->is_haswell ? 16 * 8 : devinfo->max_cs_threads;
unsigned scratch_ids_per_subslice;
if (devinfo->is_haswell) {
/* WaCSScratchSize:hsw
*
* Haswell's scratch space address calculation appears to be sparse
* rather than tightly packed. The Thread ID has bits indicating
* which subslice, EU within a subslice, and thread within an EU it
* is. There's a maximum of two slices and two subslices, so these
* can be stored with a single bit. Even though there are only 10 EUs
* per subslice, this is stored in 4 bits, so there's an effective
* maximum value of 16 EUs. Similarly, although there are only 7
* threads per EU, this is stored in a 3 bit number, giving an
* effective maximum value of 8 threads per EU.
*
* This means that we need to use 16 * 8 instead of 10 * 7 for the
* number of threads per subslice.
*/
scratch_ids_per_subslice = 16 * 8;
} else if (devinfo->is_cherryview) {
/* Cherryview devices have either 6 or 8 EUs per subslice, and each
* EU has 7 threads. The 6 EU devices appear to calculate thread IDs
* as if it had 8 EUs.
*/
scratch_ids_per_subslice = 8 * 7;
} else {
scratch_ids_per_subslice = devinfo->max_cs_threads;
}
thread_count = scratch_ids_per_subslice * subslices;
break;