From: torbenh <torbenh@gmx.de>
To: "D. Jansen" <d.g.jansen@googlemail.com>
Cc: Valdis.Kletnieks@vt.edu, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org, tytso@mit.edu
Subject: Re: [rfc] Ignore Fsync Calls in Laptop_Mode
Date: Sat, 21 May 2011 00:03:14 +0200 [thread overview]
Message-ID: <20110520220314.GA8271@siel.b> (raw)
In-Reply-To: <BANLkTikCivzqf5OJEa=ouKSvaLMTS3ayng@mail.gmail.com>
On Fri, May 20, 2011 at 06:40:49PM +0200, D. Jansen wrote:
> On Fri, May 20, 2011 at 5:28 PM, <Valdis.Kletnieks@vt.edu> wrote:
> > On Thu, 19 May 2011 15:34:46 +0200, Dennis Jansen said:
> >
> >> Testing:
> >> I've been using this workaround on my netbook for over six months now.
> >> It works as expected for me with all software in a Ubuntu 9.10
> >> environment and saves me at least 0.5 Watt or roughly 10 % battery
> >> time - without destroying my hard disk. I have seen no negative side
> >> effects.
> >
> > How much destructive testing did you do? In the 6 months, how many times did
> > the system crash (or had the battery pulled out, or whatever) while large
> > amounts of data were still pending after apps thought they were fsync'ed? How
> > much crash testing was done against apps that use fsync for ordering or
> > correctness reasons?
>
> I don't see the point in verifying the obvious. Of course applications
> that rely on fsync will lose data.
> The real problem comes with ordering correctness, which could actually
> _destroy previous data_ as well.
> In my scenario (office applications, browsing) I have not hit such a problem.
how about making fsync block until the harddisk spins up ?
this would also enable you to detect these apps you wouldnt be using in
laptop mode anyways ?
--
torben Hohn
next prev parent reply other threads:[~2011-05-20 22:03 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-19 13:34 [rfc] Ignore Fsync Calls in Laptop_Mode Dennis Jansen
2011-05-19 13:43 ` Alan Cox
[not found] ` <BANLkTikFRwPY_qOQpPmCmNUJbBUsGcuGUw@mail.gmail.com>
[not found] ` <20110519153928.40521b93@lxorguk.ukuu.org.uk>
2011-05-19 15:01 ` D. Jansen
2011-05-19 15:02 ` D. Jansen
2011-05-20 15:34 ` Valdis.Kletnieks
2011-05-20 3:39 ` Dave Chinner
2011-05-20 6:01 ` D. Jansen
2011-05-22 0:48 ` Dave Chinner
2011-05-23 8:12 ` Oliver Neukum
2011-05-23 13:05 ` D. Jansen
2011-05-25 0:00 ` Dave Chinner
2011-05-25 6:50 ` Oliver Neukum
2011-05-26 7:01 ` D. Jansen
2011-05-26 10:49 ` Theodore Tso
[not found] ` <BANLkTimNjt4=9v33Z9Nr12xa6GmyJ-Ue5A@mail.gmail.com>
2011-05-26 13:31 ` Ted Ts'o
2011-05-26 16:05 ` D. Jansen
2011-05-26 16:21 ` Ted Ts'o
2011-05-27 7:12 ` D. Jansen
2011-05-27 14:17 ` Theodore Tso
2011-05-27 17:51 ` david
2011-05-29 10:45 ` D. Jansen
2011-05-30 1:53 ` david
2011-05-30 7:13 ` Oliver Neukum
2011-05-30 12:55 ` Valdis.Kletnieks
2011-05-30 18:03 ` david
2011-05-30 13:55 ` D. Jansen
2011-05-30 18:02 ` david
2011-05-30 18:28 ` D. Jansen
2011-05-30 18:43 ` Valdis.Kletnieks
2011-05-30 19:54 ` D. Jansen
2011-05-30 18:45 ` david
2011-05-30 19:49 ` D. Jansen
2011-05-30 20:53 ` david
2011-05-30 21:24 ` D. Jansen
2011-05-30 22:41 ` david
2011-05-31 2:03 ` Ted Ts'o
2011-05-31 2:26 ` david
2011-05-31 13:47 ` D. Jansen
2011-05-31 18:23 ` david
2011-05-31 18:37 ` D. Jansen
2011-05-31 18:54 ` david
2011-05-31 19:04 ` D. Jansen
2011-06-02 7:42 ` D. Jansen
2011-05-31 8:22 ` Valdis.Kletnieks
2011-05-30 22:10 ` Jesper Juhl
2011-05-31 6:48 ` Oliver Neukum
2011-05-26 19:31 ` Matthew Garrett
2011-05-27 7:22 ` D. Jansen
2011-05-20 15:28 ` Valdis.Kletnieks
2011-05-20 16:40 ` D. Jansen
2011-05-20 22:03 ` torbenh [this message]
2011-05-21 8:23 ` D. Jansen
2011-05-23 8:22 ` Jesper Juhl
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