[Intel-gfx] [PATCH 13/14] drm/i915: Add stats for GuC log buffer flush interrupts

[Goel, Akash]

On 7/3/2016 3:14 PM, Chris Wilson wrote:
> On Sun, Jul 03, 2016 at 12:21:30AM +0530, akash.goel at intel.com wrote:
>> From: Akash Goel <akash.goel at intel.com>
>>
>> GuC firmware sends an interrupt to flush the log buffer when it
>> becomes half full. GuC firmware also tracks how many times the
>> buffer overflowed.
>> It would be useful to maintain a statistics of how many flush
>
> For what purpose? Would not tracepoints be even more useful?
Having a stats would be useful to get an idea of the volume & the rate 
at which logs are being generated from GuC side and whether Driver is 
quick enough to capture all of them.

Yes tracepoint would also be very useful.

Please see below the logging related stats, in the output of
‘i915_guc_info’ on execution of ‘gem_exec_nop’ IGT.

GuC total action count: 623531
GuC action failure count: 0
GuC last action command: 0x30
GuC last action status: 0xf0000000
GuC last action error code: 0

GuC submissions:
         render ring             :    9019910, last seqno 0x01a4390b
         blitter ring            :    6188291, last seqno 0x01a4390d
         bsd ring                :    6179075, last seqno 0x01a4390c
         video enhancement ring  :    6156547, last seqno 0x01a4390e
         Total: 27543823

GuC execbuf client @ ffff8801659fb100:
         Priority 2, GuC ctx index: 0, PD offset 0x800
         Doorbell id 0, offset: 0x0, cookie 0x1a4490f
         WQ size 8192, offset: 0x1000, tail 4336
         Work queue full: 0
         Failed to queue: 0
         Failed doorbell: 0
         Last submission result: 0
         Submissions: 9019910 render ring
         Submissions: 6188291 blitter ring
         Submissions: 6179075 bsd ring
         Submissions: 6156547 video enhancement ring
         Total: 27543823

GuC logging stats:
         ISR:     flush count     321718, overflow count        0
         DPC:     flush count     303788, overflow count        1
         CRASH:   flush count          0, overflow count        0
         Total flush interrupt count: 625511


Best regards
Akash
> -Chris
>