]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
cpuidle: governors: menu: Select polling state in some more cases
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>
Thu, 23 Oct 2025 17:12:57 +0000 (19:12 +0200)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Mon, 27 Oct 2025 13:41:27 +0000 (14:41 +0100)
commitdb86f55bf81a3a297be05ee8775ae9a8c6e3a599
tree6ff8a382e3b603b3b1ae6b9f31b30d599744c111
parentdcb6fa37fd7bc9c3d2b066329b0d27dedf8becaa
cpuidle: governors: menu: Select polling state in some more cases

A throughput regression of 11% introduced by commit 779b1a1cb13a ("cpuidle:
governors: menu: Avoid selecting states with too much latency") has been
reported and it is related to the case when the menu governor checks if
selecting a proper idle state instead of a polling one makes sense.

In particular, it is questionable to do so if the exit latency of the
idle state in question exceeds the predicted idle duration, so add a
check for that, which is sufficient to make the reported regression go
away, and update the related code comment accordingly.

Fixes: 779b1a1cb13a ("cpuidle: governors: menu: Avoid selecting states with too much latency")
Closes: https://lore.kernel.org/linux-pm/004501dc43c9$ec8aa930$c59ffb90$@telus.net/
Reported-by: Doug Smythies <dsmythies@telus.net>
Tested-by: Doug Smythies <dsmythies@telus.net>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/12786727.O9o76ZdvQC@rafael.j.wysocki
drivers/cpuidle/governors/menu.c