From: Benjamin LaHaise <bcrl@kvack.org>
To: Eric Dumazet <dada1@cosmosbay.com>
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 11:11:13 -0500 [thread overview]
Message-ID: <20070309161113.GM6209@kvack.org> (raw)
In-Reply-To: <200703091213.35691.dada1@cosmosbay.com>
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.
-ben
--
"Time is of no importance, Mr. President, only life is important."
Don't Email: <zyntrop@kvack.org>.
next prev parent reply other threads:[~2007-03-09 16:11 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 [this message]
2007-03-09 17:02 ` Pekka Enberg
2007-03-09 17:47 ` Eric Dumazet
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