From: Prarit Bhargava <prarit@redhat.com>
To: John Stultz <john.stultz@linaro.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Miroslav Lichvar <mlichvar@redhat.com>,
Richard Cochran <richardcochran@gmail.com>
Subject: Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering
Date: Fri, 25 Apr 2014 15:00:05 -0400 [thread overview]
Message-ID: <535AB0B5.8060305@redhat.com> (raw)
In-Reply-To: <1398380677-8684-1-git-send-email-john.stultz@linaro.org>
On 04/24/2014 07:04 PM, John Stultz wrote:
> Continuing the sporadic work on improving the timekeeping
> frequency steering logic when NOHZ is enabled, I've made a number
> of changes to my re-implementation of Miroslav's patch (most
> recently posted here: https://lkml.org/lkml/2014/2/12/401 ),
> and I'm getting much closer results in the simulator.
>
> Compared with Miroslav's patch, this avoids doing any extra
> divisions, and instead approximates the correction
> logarithmically. In addition to trying to lower overhead, this
> allows the other accounting bits to be managed in much the
> same way we have been doing for awhile.
>
> This patch set contains one portion from Miroslav's patch
> (ntp_tick caching) split out into a separate logical patch.
>
> Below are some of the simulator results (BTW Miroslav, w/ 3.15-rc,
> you'll need to revert b399fe355b30d01 to get the simulator building)
> comparing this patchset to Miroslav's patch to show we're getting in
> the right order of magnitude.
>
John, I'm going to put this into a weekend long test right away (along with
another unrelated cpupower patch). I'll ping back Monday to let you know how it
went.
P.
next prev parent reply other threads:[~2014-04-25 19:20 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-24 23:04 [PATCH 0/3] timekeeping: Improved NOHZ frequency steering John Stultz
2014-04-24 23:04 ` [PATCH 1/3] [RFC] timekeeping: Rework frequency adjustments to work better w/ nohz John Stultz
2014-04-24 23:04 ` [PATCH 2/3] [RFC] timekeeping: Use cached ntp_tick_length when accumulating error John Stultz
2014-04-24 23:04 ` [PATCH 3/3] [RFC] timekeeping: Loop in the freqadjust logic to speed up convergence John Stultz
2014-04-25 14:04 ` [PATCH 0/3] timekeeping: Improved NOHZ frequency steering Miroslav Lichvar
2014-04-25 21:05 ` John Stultz
2014-04-30 14:01 ` Miroslav Lichvar
2014-05-16 23:37 ` John Stultz
2014-05-17 0:04 ` John Stultz
2014-04-25 19:00 ` Prarit Bhargava [this message]
2014-04-29 11:19 ` Prarit Bhargava
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