From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
linux-fsdevel@vger.kernel.org,
Steven Rostedt <srostedt@redhat.com>,
Arjan van de Ven <arjan@linux.intel.com>
Subject: Re: [PATCH 2/2] UBIFS: start using hrtimers
Date: Fri, 29 May 2009 15:32:37 +0200 [thread overview]
Message-ID: <1243603957.23657.217.camel@twins> (raw)
In-Reply-To: <20090529150944.8912.95076.sendpatchset@localhost.localdomain>
On Fri, 2009-05-29 at 18:09 +0300, Artem Bityutskiy wrote:
> From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
> Subject: [PATCH 2/2] UBIFS: start using hrtimers
>
> UBIFS uses timers for write-buffer write-back. It is not
> crucial for us to write-back exactly on time. We are fine
> to write-back a little earlier or later. And this means
> we may optimize UBIFS timer so that it could be groped
> with a close timer event, so that the CPU would not be
> waken up just to do the write back. This is optimization
> to lessen power consumption, which is important in
> embedded devices UBIFS is used for.
>
> hrtimers have a nice feature: they are effectively range
> timers, and we may defind the soft and hard limits for
> it. Standard timers do not have these feature. They may
> only be made deferrable, but this means there is effectively
> no hard limit. So, we will better use hrtimers.
>
> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
> ---
Seems sane enough from a hrtimer POV, but isn't this already
functionality that the VFS/pdflush provide?
next prev parent reply other threads:[~2009-05-29 13:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-29 15:09 [PATCH 0/2] Use hrtimers in UBIFS Artem Bityutskiy
2009-05-29 15:09 ` [PATCH 1/2] hrtimer: export ktime_add_safe Artem Bityutskiy
2009-06-01 19:56 ` Ingo Molnar
2009-06-02 5:39 ` Artem Bityutskiy
2009-05-29 15:09 ` [PATCH 2/2] UBIFS: start using hrtimers Artem Bityutskiy
2009-05-29 13:32 ` Peter Zijlstra [this message]
2009-05-29 13:58 ` Artem Bityutskiy
2009-05-29 14:00 ` Artem Bityutskiy
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