The bspec lists both the clock frequency and the effective interval. The
interval corresponds to observed behaviour, so adjust the frequency to
match.
v2: Mika rightfully asked if we could measure the clock frequency from a
selftest.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200427154554.12736-1-chris@chris-wilson.co.uk
After having testing all the RPS controls individually, we need to take
a step back and check how our RPS worker integrates them to perform
dynamic GPU reclocking. So do that by submitting a spinner and wait and
see what happens.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200420172739.11620-6-chris@chris-wilson.co.uk
One of the core tenents of reclocking the GPU is that its throughput
scales with the clock frequency. We can observe this by incrementing a
loop counter on the GPU, and compare the different execution rates at
the notional RPS frequencies.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200420172739.11620-1-chris@chris-wilson.co.uk
A basic premise of RPS is that at lower frequencies, not only do we run
slower, but we save power compared to higher frequencies. For example,
when idle, we set the minimum frequency just in case there is some
residual current. Since the power curve should be a physical
relationship, if we find no power saving it's likely that we've broken
our frequency handling, so test!
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200417152018.13079-2-chris@chris-wilson.co.uk
Since we depend upon RPS generating interrupts after evaluation
intervals to determine when to up/down clock the GPU, it is imperative
that we successfully enable interrupt generation! Verify that we do see
an interrupt if we keep the GPU busy for an entire EI.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200415170318.16771-1-chris@chris-wilson.co.uk