2014-02-18 18:34 GMT-03:00 Paulo Zanoni <przanoni@xxxxxxxxx>:
> 2014-02-18 16:25 GMT-03:00 Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>:
>> Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> writes:
>>
>>> We currently call intel_mark_idle() too often, as we do so as a
>>> side-effect of processing the request queue. However, we the calls to
>>> intel_mark_idle() are expected to be paired with a call to
>>> intel_mark_busy() (or else we try to idle the hardware by accessing
>>> registers that are already disabled). Make the idle/busy tracking
>>> explicit to prevent the multiple calls.
>>>
>>> Reported-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>
>>> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
>>> Cc: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>
>
> Thanks!
>
> I tested it and this patch + another local patch I have fix the
> problem that can be reproduced by the "gem-idle" subtest of pm_pc8.c
> (I still did not commit the subtest, but will do it soon).
>
> Also, I guess this patch deprecates dev_priv->pc8.gpu_idle. I had
> plans to move it to dev_priv->pm.gpu_idle, but now I'll try to kill
> it.
>
>>> ---
>>> drivers/gpu/drm/i915/i915_drv.h | 8 ++++++++
>>> drivers/gpu/drm/i915/i915_gem.c | 4 +---
>>> drivers/gpu/drm/i915/intel_display.c | 11 +++++++++++
>>> drivers/gpu/drm/i915/intel_drv.h | 2 +-
>>> 4 files changed, 21 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>>> index 00222cc..8441c8a 100644
>>> --- a/drivers/gpu/drm/i915/i915_drv.h
>>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>>> @@ -1134,6 +1134,14 @@ struct i915_gem_mm {
>>> */
>>> bool interruptible;
>>>
>>> + /**
>>> + * Is the GPU currently considered idle, or busy executing userspace
>>> + * requests? Whilst idle, we attempt to power down the hardware and
>>> + * display clocks. In order to reduce the effect on performance, there
>>> + * is a slight delay before we do so.
>>> + */
>>> + bool busy;
Hi
Also, don't we want to init this to true, since the first thing called
seems to be intel_mark_idle?
I get intel_mark_idle called at 6 seconds after booting, then
intel_mark_busy is called only 19 seconds after booting.
I found this while writing the patch to deprecate dev_priv->pc8.gpu_idle :)
Thanks,
Paulo
>>> +
>>> /** Bit 6 swizzling required for X tiling */
>>> uint32_t bit_6_swizzle_x;
>>> /** Bit 6 swizzling required for Y tiling */
>>> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
>>> index 9a40ef5..4525dd7 100644
>>> --- a/drivers/gpu/drm/i915/i915_gem.c
>>> +++ b/drivers/gpu/drm/i915/i915_gem.c
>>> @@ -2315,7 +2315,6 @@ int __i915_add_request(struct intel_ring_buffer *ring,
>>> i915_gem_context_reference(request->ctx);
>>>
>>> request->emitted_jiffies = jiffies;
>>> - was_empty = list_empty(&ring->request_list);
>>> list_add_tail(&request->list, &ring->request_list);
>>> request->file_priv = NULL;
>>>
>>> @@ -2336,12 +2335,11 @@ int __i915_add_request(struct intel_ring_buffer *ring,
>>> if (!dev_priv->ums.mm_suspended) {
>>> i915_queue_hangcheck(ring->dev);
>>>
>>> - if (was_empty) {
>>> + if (intel_mark_busy(dev_priv->dev)) {
>
> I'm new to this code, so forgive me if I'm way off. Now that we
> changed the relative order, isn't it possible that we run the code
> line above, marking the device as busy, and then just before the next
> line runs, the still-not-canceled idle_work function runs and marks
> the device as idle? That could be bad, right?
>
> Also, why do we need the change on this function?
>
>
>>> cancel_delayed_work_sync(&dev_priv->mm.idle_work);
>>> queue_delayed_work(dev_priv->wq,
>>> &dev_priv->mm.retire_work,
>>> round_jiffies_up_relative(HZ));
>>> - intel_mark_busy(dev_priv->dev);
>>> }
>>> }
>>>
>>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>>> index e127b23..bfd6396 100644
>>> --- a/drivers/gpu/drm/i915/intel_display.c
>>> +++ b/drivers/gpu/drm/i915/intel_display.c
>>> @@ -8220,8 +8220,14 @@ void intel_mark_busy(
>>
>> bool intel_mark_busy(struct drm_device *dev)
>>
>> -Mika
>
> Exactly.
>
> Thanks,
> Paulo
>
>>
>>> {
>>> struct drm_i915_private *dev_priv = dev->dev_private;
>>>
>>> + if (dev_priv->mm.busy)
>>> + return false;
>>> +
>>> hsw_package_c8_gpu_busy(dev_priv);
>>> i915_update_gfx_val(dev_priv);
>>> + dev_priv->mm.busy = true;
>>> +
>>> + return true;
>>> }
>>>
>>> void intel_mark_idle(struct drm_device *dev)
>>> @@ -8229,6 +8235,11 @@ void intel_mark_idle(struct drm_device *dev)
>>> struct drm_i915_private *dev_priv = dev->dev_private;
>>> struct drm_crtc *crtc;
>>>
>>> + if (!dev_priv->mm.busy)
>>> + return;
>>> +
>>> + dev_priv->mm.busy = false;
>>> +
>>> hsw_package_c8_gpu_idle(dev_priv);
>>>
>>> if (!i915.powersave)
>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>>> index e5e1a5c..4c329e0 100644
>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>> @@ -656,7 +656,7 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
>>> const char *intel_output_name(int output);
>>> bool intel_has_pending_fb_unpin(struct drm_device *dev);
>>> int intel_pch_rawclk(struct drm_device *dev);
>>> -void intel_mark_busy(struct drm_device *dev);
>>> +bool intel_mark_busy(struct drm_device *dev);
>>> void intel_mark_fb_busy(struct drm_i915_gem_object *obj,
>>> struct intel_ring_buffer *ring);
>>> void intel_mark_idle(struct drm_device *dev);
>>> --
>>> 1.7.9.5
>>>
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>
>
>
> --
> Paulo Zanoni
--
Paulo Zanoni
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