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From: Nick Piggin <nickpiggin@yahoo.com.au>
To: "Ray Lee" <ray-lk@madrabbit.org>
Cc: "Eric Dumazet" <dada1@cosmosbay.com>,
	"David Miller" <davem@davemloft.net>,
	dmantipov@yandex.ru, linux-kernel@vger.kernel.org
Subject: Re: Are Linux pipes slower than the FreeBSD ones ?
Date: Thu, 6 Mar 2008 03:02:06 +1100	[thread overview]
Message-ID: <200803060302.07084.nickpiggin@yahoo.com.au> (raw)
In-Reply-To: <2c0942db0803050755u7e17118h923328fb79ee206b@mail.gmail.com>

On Thursday 06 March 2008 02:55, Ray Lee wrote:
> On Wed, Mar 5, 2008 at 7:38 AM, Nick Piggin <nickpiggin@yahoo.com.au> wrote:

> >  Yeah, but why does the pipe inode need to have its times updated?
> >  I guess there is some reason... hopefully not C&P related.
>
> In principle so that the reader or writer can find out the last time
> the other end did any processing of the pipe. And yeah, for POSIX
> compliance: "Upon successful completion, pipe() will mark for update
> the st_atime, st_ctime and st_mtime fields of the pipe. "

Thanks.

> But it'd be 
> nice if there were a way to avoid touching it more than once a second
> (note the 'will mark for update' language). Or if the pipe is a
> physical FIFO on a noatime filesystem?

I doubt it really matters for anything except this test. I wouldn't
bother doing anything fancy really. It just caught my eye and I was
wondering why it was there at all.

Thanks,
Nick


  reply	other threads:[~2008-03-05 16:02 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-05  7:46 Antipov Dmitry
2008-03-05  8:00 ` David Miller
2008-03-05  9:47   ` Eric Dumazet
2008-03-05 10:19     ` Andi Kleen
2008-03-05 12:12     ` David Newall
2008-03-05 14:20     ` Nick Piggin
2008-03-05 14:55       ` Eric Dumazet
2008-03-05 15:38         ` Nick Piggin
2008-03-05 15:55           ` Ray Lee
2008-03-05 16:02             ` Nick Piggin [this message]
2008-03-06 12:11       ` Dmitry Antipov
2008-03-17 12:53         ` Nick Piggin

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