From: Eric Dumazet <dada1@cosmosbay.com>
To: Benjamin LaHaise <bcrl@kvack.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
hch@infradead.org, alan@lxorguk.ukuu.org.uk, serue@us.ibm.com
Subject: Re: [PATCH 2/7] revoke: add f_light flag for struct file
Date: Fri, 9 Mar 2007 18:47:06 +0100 [thread overview]
Message-ID: <200703091847.06604.dada1@cosmosbay.com> (raw)
In-Reply-To: <20070309161113.GM6209@kvack.org>
On Friday 09 March 2007 17:11, Benjamin LaHaise wrote:
> On Fri, Mar 09, 2007 at 12:13:35PM +0100, Eric Dumazet wrote:
> > Then just drop the fget_light() 'optimisation' and always take a
> > reference (atomic on f_count) regardless of single-thread or not. Instead
> > of dirtying f_light, just do the straightforward thing and be with it.
> >
> > (that is : fget_light() = fget() = no more keeping fput_needed
> > everywhere, and convoluted things in some dark sides of the kernel.
>
> And it makes things rather slower for a lot of single threaded applications
> on modern systems. Yes, fget_light can be done much more cleanly, but
> please don't go around ripping out optimizations just because.
Sure. But I apparently was the only guy to react to the f_light horror story.
And it seems a solution was found, after some mail exchanges.
In French we have this expression : "Precher le faux pour savoir le vrai"
You could translate to "make false statements in order to discover the truth"
or "to tell a lie in order to get at the truth" or maybe "playing the devil's
advocate", but really the French one is better :)
prev parent reply other threads:[~2007-03-09 17:47 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-09 8:14 Pekka J Enberg
2007-03-09 10:08 ` Eric Dumazet
2007-03-09 10:43 ` Pekka Enberg
2007-03-09 11:13 ` Eric Dumazet
2007-03-09 11:52 ` Pekka Enberg
2007-03-09 11:58 ` Pekka Enberg
2007-03-09 14:12 ` Alan Cox
2007-03-09 13:13 ` Pekka J Enberg
2007-03-09 16:11 ` Benjamin LaHaise
2007-03-09 17:02 ` Pekka Enberg
2007-03-09 17:47 ` Eric Dumazet [this message]
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