linux-kernel - Re: [PATCH] timers: Don't wake ktimersoftd on every tick

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Date:   Fri, 10 Feb 2017 18:02:08 +0100
From:   Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To:     Haris Okanovic <haris.okanovic@...com>
Cc:     linux-rt-users@...r.kernel.org, linux-kernel@...r.kernel.org,
        tglx@...utronix.de, julia.cartwright@...com, gratian.crisan@...com
Subject: Re: [PATCH] timers: Don't wake ktimersoftd on every tick

On 2017-02-03 12:21:12 [-0600], Haris Okanovic wrote:
> Collect expired timers in interrupt context to avoid overhead of waking
> ktimersoftd on every tick. ktimersoftd now wakes only when one or more
> timers are ready, which yields a minor reduction in small latency spikes.
> 
> This is implemented by storing lists of expired timers in timer_base,
> updated on each tick. Any addition to the lists wakes ktimersoftd
> (softirq) to process those timers.
> 
> Please refer to the following RFC threads for more details:
> https://www.spinics.net/lists/linux-rt-users/msg16095.html
> https://www.spinics.net/lists/linux-rt-users/msg16113.html
> 
> Signed-off-by: Haris Okanovic <haris.okanovic@...com>

applied.

Sebastian