linux-kernel - Re: [rfc] Ignore Fsync Calls in Laptop

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Message-Id: <201105310848.15148.oneukum@suse.de>
Date:	Tue, 31 May 2011 08:48:14 +0200
From:	Oliver Neukum <oneukum@...e.de>
To:	david@...g.hm
Cc:	"D. Jansen" <d.g.jansen@...glemail.com>,
	Theodore Tso <tytso@....edu>, akpm@...ux-foundation.org,
	linux-kernel@...r.kernel.org, Dave Chinner <david@...morbit.com>,
	njs@...ox.com, bart@...wel.tk
Subject: Re: [rfc] Ignore Fsync Calls in Laptop_Mode

Am Montag, 30. Mai 2011, 20:45:42 schrieb david@...g.hm:
> > The big problem is that so far only fsync existed and lots of software
> > seemingly abuses it as an expensive write barrier. And it would really
> > be lovely to have the choice to stop that on an opt-in basis in laptop
> > mode.
> 
> is the benifit of not spinning up the disk really worth the risk of 
> loosing data?

That is a policy question.

> and should this really be a global across-the-board option?

Possibly not. However this is a secondary question.

> the problem is that most users don't know what their system is running, or 
> what effect disaling fsync would have. those that do can probably use 
> LD_PRELOAD to override fsync calls.

Not without a loss of ordering, as we have discussed.

	Regards
		Oliver
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