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[PATCH 0/2] xen/cpufreq: a couple of fixes for the sampling window


  • To: xen-devel@xxxxxxxxxxxxxxxxxxxx
  • From: Roger Pau Monne <roger.pau@xxxxxxxxxx>
  • Date: Fri, 27 Feb 2026 08:32:57 +0100
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  • Cc: Roger Pau Monne <roger.pau@xxxxxxxxxx>, Jan Beulich <jbeulich@xxxxxxxx>
  • Delivery-date: Fri, 27 Feb 2026 07:33:21 +0000
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

Hello,

Since a month or so I've noticed that my only text box that supports
P-states would seem to eventually get all its CPUs stuck in the lower
frequency P-state, and no amount of load would result in a P-state
change.

The issue has always been intermittent, and not easy to reproduce.
Looking at the on-demand governor I've found the two issues fixed on
this series.  With those fixed I haven't been able to reproduce the
issue, but as said I don't have a deterministic way to trigger it.

Anyway, the fixes look legit, so regardless of whether there's something
else causing my issue, we should take those.  I'm a bit surprised no-one
has noticed wonky performance with the on-demand governor before; the
changes that introduce those issue have been there since the governor
was introduced.  Neither I know why I've only noticed the low frequency
stickiness issue ~last month, if it was indeed caused by the issues
here.

Thanks, Roger.

Roger Pau Monne (2):
  xen/cpufreq: fix adjusting of sampling window on early exit
  xen/cpufreq: fix usages of align_timer() in the on-demand governor

 xen/drivers/cpufreq/cpufreq_ondemand.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

-- 
2.51.0




 


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