Re: [PATCH] drm/i915: Small display interrupt handlers tidy

Tvrtko Ursulin
2016-05-06T13:27:28Z

On 06/05/16 12:27, Chris Wilson wrote:
> On Fri, May 06, 2016 at 12:07:04PM +0100, Tvrtko Ursulin wrote:
>> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>>
>> I have noticed some of our interrupt handlers use both dev and
>> dev_priv while they could get away with only dev_priv in the
>> huge majority of cases.
>>
>> Tidying that up had a cascading effect on changing functions
>> prototypes, so relatively big churn factor, but I think it is
>> for the better.
>>
>> For example even where changes cascade out of i915_irq.c, for
>> functions prefixed with intel_, genX_ or <plat>_, it makes more
>> sense to take dev_priv directly anyway.
>>
>> This allows us to eliminate local variables and intermixed usage
>> of dev and dev_priv where only one is good enough.
>>
>> End result is shrinkage of both source and the resulting binary.
>>
>> i915.ko:
>>
>> - .text 000b0899
>> + .text 000b0619
>>
>> Or if we look at the Gen8 display irq chain:
>>
>> -00000000000006ad t gen8_irq_handler
>> +0000000000000663 t gen8_irq_handler
>> -0000000000000028 T intel_opregion_asle_intr
>> +0000000000000024 T intel_opregion_asle_intr
>> -000000000000008c t ilk_hpd_irq_handler
>> +000000000000007f t ilk_hpd_irq_handler
>> -0000000000000116 T intel_check_page_flip
>> +0000000000000112 T intel_check_page_flip
>> -000000000000011a T intel_prepare_page_flip
>> +0000000000000119 T intel_prepare_page_flip
>> -0000000000000014 T intel_finish_page_flip_plane
>> +0000000000000013 T intel_finish_page_flip_plane
>> -0000000000000053 t hsw_pipe_crc_irq_handler
>> +000000000000004c t hsw_pipe_crc_irq_handler
>> -000000000000022e t cpt_irq_handler
>> +0000000000000213 t cpt_irq_handler
>>
>> So small shrinkage but it is all fast paths so doesn't harm.
>>
>> Situation is similar in other interrupt handlers as well.
>>
>> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>> ---
>> drivers/gpu/drm/i915/i915_drv.c | 2 +-
>> drivers/gpu/drm/i915/i915_drv.h | 13 +-
>> drivers/gpu/drm/i915/i915_irq.c | 386 ++++++++++++++++------------------
>> drivers/gpu/drm/i915/intel_display.c | 33 ++-
>> drivers/gpu/drm/i915/intel_drv.h | 12 +-
>> drivers/gpu/drm/i915/intel_hotplug.c | 13 +-
>> drivers/gpu/drm/i915/intel_opregion.c | 4 +-
>> drivers/gpu/drm/i915/intel_pm.c | 33 ++-
>> 8 files changed, 232 insertions(+), 264 deletions(-)
>
> I have a similar series with almost identical impact, so from that
> perspective we should be close. I found we could measure an improvement
> in IRQ waiter wakeup latency (but only about ~2% so right on the noise
> level) for gen6/gen7.
>
> Patch looks good, spot checking against mine:
>
> @@ -1617,8 +1617,7 @@ void gen6_rps_idle(struct drm_i915_private *dev_priv);
> void gen6_rps_boost(struct drm_i915_private *dev_priv,
> struct intel_rps_client *rps,
> unsigned long submitted);
> -void intel_queue_rps_boost_for_request(struct drm_device *dev,
> - struct drm_i915_gem_request *req);
> +void intel_queue_rps_boost_for_request(struct drm_i915_gem_request *req);

Against your tree or your patch? If latter that would be quite amazing!

> Follow up whilst waiting for CI?

Sure.

> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

Thanks!

Regards,

Tvrtko