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| author | Paolo Bonzini <[email protected]> | 2015-09-15 16:27:57 +0000 |
|---|---|---|
| committer | Paolo Bonzini <[email protected]> | 2015-09-16 10:17:00 +0000 |
| commit | 62bea5bff486644ecf363fe8a1a2f6f32c614a49 (patch) | |
| tree | 774180da187dabef4995896aec803248b075a36d /drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | |
| parent | kvm: fix zero length mmio searching (diff) | |
| download | kernel-62bea5bff486644ecf363fe8a1a2f6f32c614a49.tar.gz kernel-62bea5bff486644ecf363fe8a1a2f6f32c614a49.zip | |
KVM: add halt_attempted_poll to VCPU stats
This new statistic can help diagnosing VCPUs that, for any reason,
trigger bad behavior of halt_poll_ns autotuning.
For example, say halt_poll_ns = 480000, and wakeups are spaced exactly
like 479us, 481us, 479us, 481us. Then KVM always fails polling and wastes
10+20+40+80+160+320+480 = 1110 microseconds out of every
479+481+479+481+479+481+479 = 3359 microseconds. The VCPU then
is consuming about 30% more CPU than it would use without
polling. This would show as an abnormally high number of
attempted polling compared to the successful polls.
Acked-by: Christian Borntraeger <[email protected]<
Reviewed-by: David Matlack <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
Diffstat (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c')
0 files changed, 0 insertions, 0 deletions