Summary: | [HSW]: power usage rises a lot after resume from suspend to ram | ||||||
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Product: | DRI | Reporter: | Arkadiusz Miskiewicz <arekm> | ||||
Component: | DRM/Intel | Assignee: | Intel GFX Bugs mailing list <intel-gfx-bugs> | ||||
Status: | CLOSED INVALID | QA Contact: | Intel GFX Bugs mailing list <intel-gfx-bugs> | ||||
Severity: | normal | ||||||
Priority: | medium | CC: | intel-gfx-bugs | ||||
Version: | DRI git | ||||||
Hardware: | x86-64 (AMD64) | ||||||
OS: | All | ||||||
Whiteboard: | |||||||
i915 platform: | i915 features: | ||||||
Attachments: |
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Description
Arkadiusz Miskiewicz
2014-09-16 06:34:07 UTC
(In reply to comment #0) > It happens with minimal userspace, so I don't blame userspace. powertop > estimates that 17W is used by "CPU core" (I assume intel gpu hides under > this, too). "perf top" doesn't show any obvious suspects. The GPU itself is measured separately, but that only really measures the EU power, not the display or the influence of the GPU on the L3 cache ring. (I would expect the ring power to be tallied under the CPU, so it is entirely possible the GPU is causing it to run at maximum frequency and we end up blaming the CPU.) Best hope is that this is an easily identifiable kernel regression. *fingers crossed* Looks like GPU is innocent. This machine has 8 cores (4 normal and 4 HT). I was using maxcpus=4 (due to Dell XPS 15 bugs like whining coil). My current theory is that after resume from ram these 4 HT cores are eating power. Why? Because if not using maxcpus option then everything fine and there is no issue at all. It could be called kernel bug to not shut up these additional cores after resume but well... ... and workaround that gets power usage to normal when using maxcpus=X for cpu in $(grep -l 0 /sys/devices/system/cpu/cpu*/online); do echo 1 > $cpu sleep 1 echo 0 > $cpu done Arkadiusz, thanks for following up with this. I'd like to ask you to do one more thing, though: please file a bug on https://bugzilla.kernel.org/ or the linux-kernel mailing list. Thanks. |
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