On 2012-08-02 00:20, James Bottomley wrote:
On Wed, 2012-08-01 at 22:08 -0700, bwidawsk wrote:
On 2012-08-01 03:06, Chris Wilson wrote:
On Wed, 01 Aug 2012 10:38:36 +0100, James Bottomley James.Bottomley@HansenPartnership.com wrote:
On Wed, 2012-08-01 at 09:58 +0100, Chris Wilson wrote:
On Wed, 01 Aug 2012 09:45:04 +0100, James Bottomley
James.Bottomley@HansenPartnership.com wrote:
On Wed, 2012-08-01 at 09:16 +0100, Chris Wilson wrote: > On Wed, 01 Aug 2012 09:06:12 +0100, James Bottomley
James.Bottomley@HansenPartnership.com wrote:
> > I got the attached to apply and it doesn't really improve
the idle power
> > much (12.5W). > > That's good to know. Next step is to try overriding
i915.semaphores.
> Can you please test with i915.semaphores=0 and
i915.semaphores=1?
There's not much point doing i915_semaphores=1 since that's
the
default
on gen 6 hardware, but i915_semaphores=0 recovers and idle
power
of
~6.5W
It is only the default if iommu is off, and changing the
default
was one of the side-effects of the patch you bisected.
Can you please login to the desktop, let it idle, record /sys/kernel/debug/dri/0/i915_cur_delayinfo and
.../i915_drpc_info.
Then trace-cmd record -e i915 sleep 10s,
OK, what is trace-cmd? It looks similar to perf tools ... is
that
it?
Yes, it is roughly equivalent and you should be able to achieve
the
same with perf trace - except I haven't done it before so I don't have quick advice on how to drive it. :) -Chris
Should be something like: perf record -f -g -e i915:* -a
I already sent the output of trace-cmd ... is that enough?
James
Yes, should do. Have we already eliminated the obvious? GPU semaphores will give time back to the GPU clients normally waiting on such things, X, XFCE, whatever else. It'd probably be handy to begin investigating what those guys are doing with their new extra time. Chris, this is what I was getting at on IRC the other day. What do you think?