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From: Arjan van de Ven <arjan@linux.intel.com>
To: Preeti U Murthy <preeti@linux.vnet.ibm.com>,
	linux-pm@vger.kernel.org, rjw@rjwysocki.net,
	linux-kernel@vger.kernel.org, len.brown@intel.com
Cc: benh@kernel.crashing.org, daniel.lezcano@linaro.org,
	srivatsa.bhat@linux.vnet.ibm.com, paulmck@linux.vnet.ibm.com,
	svaidy@linux.vnet.ibm.com
Subject: Re: [PATCH V3] cpuidle/governors: Fix logic in selection of idle states
Date: Tue, 04 Feb 2014 06:52:15 -0800	[thread overview]
Message-ID: <52F0FE9F.501@linux.intel.com> (raw)
In-Reply-To: <20140204083531.24802.63370.stgit@preeti.in.ibm.com>

On 2/4/2014 12:35 AM, Preeti U Murthy wrote:
> The cpuidle governors today are not handling scenarios where no idle state
> can be chosen. Such scenarios coud arise if the user has disabled all the
> idle states at runtime or the latency requirement from the cpus is very strict.
>
> The menu governor returns 0th index of the idle state table when no other
> idle state is suitable. This is even when the idle state corresponding to this
> index is disabled or the latency requirement is strict and the exit_latency
> of the lowest idle state is also not acceptable. Hence this patch
> fixes this logic in the menu governor by defaulting to an idle state index
>  of -1 unless any other state is suitable.

state 0 is defined as polling, and polling ALWAYS should be ok


  reply	other threads:[~2014-02-04 14:52 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-04  8:35 [PATCH V3] cpuidle/governors: Fix logic in selection of idle states Preeti U Murthy
2014-02-04 14:52 ` Arjan van de Ven [this message]
2014-02-05  4:00   ` Preeti U Murthy

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