Message-ID: <563C0FE8.8070301@redhat.com>
Date: Thu, 05 Nov 2015 21:26:48 -0500
From: Rik van Riel <riel@redhat.com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0
MIME-Version: 1.0
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
CC: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        rafael.j.wysocki@intel.com, arjan@linux.intel.com, len.brown@intel.com,
        daniel.lezcano@linaro.org
Subject: Re: [PATCH 0/3] cpuidle: small improvements & fixes for menu governor
 (resend)
References: <1446590059-18897-1-git-send-email-riel@redhat.com> <1547516.IzrSrfmAQk@vostro.rjw.lan>
In-Reply-To: <1547516.IzrSrfmAQk@vostro.rjw.lan>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1579
Lines: 38

On 11/05/2015 05:34 PM, Rafael J. Wysocki wrote:
> On Tuesday, November 03, 2015 05:34:16 PM riel@redhat.com wrote:
>> While working on a paravirt cpuidle driver for KVM guests, I
>> noticed a number of small logic errors in the menu governor
>> code.
>>
>> These patches should get rid of some artifacts that can break
>> the logic in the menu governor under certain corner cases, and
>> make idle state selection work better on CPUs with long C1 exit
>> latencies.
>>
>> I have not seen any adverse effects with them in my (quick)
>> tests. As expected, they do not seem to do much on systems with
>> many power states and very low C1 exit latencies and target residencies. 
> 
> Thanks!
> 
> The patches look good to me.
> 
> I might apply [1-2/3] right away, but I'm a bit hesitant about the [3/3] (I'd
> like it to spend some time in linux-next before it goes to Linus).  Also, we've
> lived without these changes for quite some time and I don't want to stretch the
> process too much, so I'll queue them up for v4.5 if that's not a problem.

Not a problem at all. I am all for taking these changes carefully,
and seeing what happens.

I did some basic testing with it, but the permutations of what
can happen with cpuidle management are just too many to predict
in advance everything that could happen.

-- 
All rights reversed
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/