From: Eric Dumazet <eric.dumazet@gmail.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
John Stultz <john.stultz@linaro.org>, Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <peterz@infradead.org>,
Eric Dumazet <dada1@cosmosbay.com>,
Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: [RFC patch 0/8] timekeeping: Implement shadow timekeeper to shorten in kernel reader side blocking
Date: Thu, 21 Feb 2013 15:06:49 -0800 [thread overview]
Message-ID: <1361488009.32484.1.camel@edumazet-glaptop> (raw)
In-Reply-To: <20130221220147.719832397@linutronix.de>
On Thu, 2013-02-21 at 22:51 +0000, Thomas Gleixner wrote:
> Now the obvious question whether this is worth the trouble can be
> answered easily. Preempt-RT users and HPC folks have complained about
> the long write hold time of the timekeeping seqcount since years and a
> quick test on a preempt-RT enabled kernel shows, that this series
> lowers the maximum latency on the non-timekeeping cores from 8 to 4
> microseconds. That's a whopping factor of 2. Defintely worth the
> trouble!
Thanks for doing this !
prev parent reply other threads:[~2013-02-21 23:06 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-21 22:51 Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 1/8] timekeeping: Calc stuff once Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 2/8] timekeeping: Make jiffies_lock internal Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 3/8] timekeeping: Move lock out of timekeeper struct Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 5/8] timekeeping: Store cycle_last value in timekeeper struct as well Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 4/8] timekeeping: Split timekeeper_lock into lock and seqcount Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 6/8] timekeeping: Delay update of clock->cycle_last Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 7/8] timekeeping: Implement a shadow timekeeper Thomas Gleixner
2013-02-22 23:53 ` John Stultz
2013-02-26 12:17 ` Thomas Gleixner
2013-02-21 22:51 ` [RFC patch 8/8] timekeeping: Shorten seq_count region Thomas Gleixner
2013-02-21 23:06 ` Eric Dumazet [this message]
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