[Mesa-dev] [PATCH] i965: Always enable VF statistics

[Eric Anholt]

Kenneth Graunke <kenneth at whitecape.org> writes:

> On Wednesday, November 12, 2014 06:54:31 PM Ben Widawsky wrote:
>> Every other unit in the geometry pipeline automatically enables
>> statistics gathering. This part of the pipe has been controlled by the
>> DEBUG_STATS variable, but this is asymmetric. This dates back to the
>> original implementation, and I am not sure if there is a reason for it.
>> 
>> I need access to these stats to implement ARB_pipeline_statistics_query.
>> 
>> Eric wrote it, and Ken touched it last. Do you have any opposition?
>> 
>> Cc: Eric Anholt <eric at anholt.net>
>> Cc: Kenneth Graunke <kenneth at whitecape.org>
>> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
>> ---
>>  src/mesa/drivers/dri/i965/brw_misc_state.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>> 
>> diff --git a/src/mesa/drivers/dri/i965/brw_misc_state.c 
> b/src/mesa/drivers/dri/i965/brw_misc_state.c
>> index 99fcddc..2c40814 100644
>> --- a/src/mesa/drivers/dri/i965/brw_misc_state.c
>> +++ b/src/mesa/drivers/dri/i965/brw_misc_state.c
>> @@ -929,8 +929,7 @@ brw_upload_invariant_state(struct brw_context *brw)
>>     const uint32_t _3DSTATE_VF_STATISTICS =
>>        is_965 ? GEN4_3DSTATE_VF_STATISTICS : GM45_3DSTATE_VF_STATISTICS;
>>     BEGIN_BATCH(1);
>> -   OUT_BATCH(_3DSTATE_VF_STATISTICS << 16 |
>> -	     (unlikely(INTEL_DEBUG & DEBUG_STATS) ? 1 : 0));
>> +   OUT_BATCH(_3DSTATE_VF_STATISTICS << 16 | 1);
>>     ADVANCE_BATCH();
>>  }
>
> My only complaint about this patch is that it doesn't go far enough.  I'm 100% 
> for removing DEBUG_STATS completely.  I've never seen any performance penalty 
> for enabling statistics.  I think we should leave them on except when there's 
> some reason to turn them off (i.e. brw->meta_in_progress flag in the clipper, 
> which prevents us from counting i.e. glClear).

Presumably there's some tiny power cost.  I don't know if it's a relevat
amount of power, though.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 818 bytes
Desc: not available
URL: <http://lists.freedesktop.org/archives/mesa-dev/attachments/20141113/6827823d/attachment.sig>