From: Benjamin LaHaise <bcrl@redhat.com>
To: "David S. Miller" <davem@redhat.com>
Cc: marcelo@conectiva.com.br, andrea@suse.de, torvalds@transmeta.com,
linux-kernel@vger.kernel.org
Subject: Re: Locking comment on shrink_caches()
Date: Tue, 25 Sep 2001 18:16:43 -0400 [thread overview]
Message-ID: <20010925181643.D19494@redhat.com> (raw)
In-Reply-To: <Pine.LNX.4.21.0109251601360.2193-100000@freak.distro.conectiva> <20010925.132905.32720330.davem@redhat.com> <20010925170055.B19494@redhat.com> <20010925.145547.90825509.davem@redhat.com>
In-Reply-To: <20010925.145547.90825509.davem@redhat.com>; from davem@redhat.com on Tue, Sep 25, 2001 at 02:55:47PM -0700
On Tue, Sep 25, 2001 at 02:55:47PM -0700, David S. Miller wrote:
> I'm willing to investigate using RCU. However, per hashchain locking
> is a much proven technique (inside the networking in particular) which
> is why that was the method employed. At the time the patch was
> implemented, the RCU stuff was not fully formulated.
*nod*
> Please note that the problem is lock cachelines in dirty exclusive
> state, not a "lock held for long time" issue.
Ahh, that's a cpu bug -- one my athlons don't suffer from.
> I agree. But to my understanding, and after having studied the
> pagecache lock usage, it was minimally used and not used in any places
> unnecessarily as per the io_request_lock example you are stating.
>
> In fact, the pagecache_lock is mostly held for extremely short periods
> of time.
True, and that is why I would like to see more of the research that
justifies these changes, as well as comparisons with alternate techniques
before any of these patches make it into the base tree. Even before that,
we need to clean up the code first.
-ben
next prev parent reply other threads:[~2001-09-25 22:16 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-09-25 17:49 Locking comment on shrink_caches() Marcelo Tosatti
2001-09-25 19:57 ` David S. Miller
2001-09-25 18:40 ` Marcelo Tosatti
2001-09-25 20:15 ` David S. Miller
2001-09-25 19:02 ` Marcelo Tosatti
2001-09-25 20:29 ` David S. Miller
2001-09-25 21:00 ` Benjamin LaHaise
2001-09-25 21:55 ` David S. Miller
2001-09-25 22:16 ` Benjamin LaHaise [this message]
2001-09-25 22:28 ` David S. Miller
2001-09-26 16:40 ` Alan Cox
2001-09-26 17:25 ` Linus Torvalds
2001-09-26 17:40 ` Alan Cox
2001-09-26 17:44 ` Linus Torvalds
2001-09-26 18:01 ` Benjamin LaHaise
2001-09-26 18:01 ` Dave Jones
2001-09-26 20:20 ` Vojtech Pavlik
2001-09-26 20:24 ` Vojtech Pavlik
2001-09-26 17:43 ` Richard Gooch
2001-09-26 18:24 ` Benjamin LaHaise
2001-09-26 18:48 ` Richard Gooch
2001-09-26 18:58 ` Davide Libenzi
2001-09-26 17:45 ` Dave Jones
2001-09-26 17:50 ` Alan Cox
2001-09-26 17:59 ` Dave Jones
2001-09-26 18:07 ` Alan Cox
2001-09-26 18:09 ` Padraig Brady
2001-09-26 18:22 ` Dave Jones
2001-09-26 18:24 ` Linus Torvalds
2001-09-26 18:40 ` Dave Jones
2001-09-26 19:12 ` Linus Torvalds
2001-09-27 12:22 ` CPU frequency shifting "problems" Padraig Brady
2001-09-27 12:44 ` Dave Jones
2001-09-27 23:23 ` Linus Torvalds
2001-09-28 0:55 ` Alan Cox
2001-09-28 2:12 ` Stefan Smietanowski
2001-09-28 8:55 ` Jamie Lokier
2001-09-28 16:11 ` Linus Torvalds
2001-09-28 20:29 ` Eric W. Biederman
2001-09-28 22:24 ` Jamie Lokier
2001-09-26 19:04 ` Locking comment on shrink_caches() George Greer
2001-09-26 18:59 ` George Greer
2001-09-26 23:26 ` David S. Miller
2001-09-27 12:10 ` Alan Cox
2001-09-27 15:38 ` Linus Torvalds
2001-09-27 17:44 ` Ingo Molnar
2001-09-27 19:41 ` David S. Miller
2001-09-27 22:59 ` Alan Cox
2001-09-25 22:03 ` Andrea Arcangeli
2001-09-25 20:24 ` Rik van Riel
2001-09-25 20:28 ` David S. Miller
2001-09-25 21:05 ` Andrew Morton
2001-09-25 21:48 ` David S. Miller
[not found] ` <200109252215.f8PMFDa02034@eng2.beaverton.ibm.com>
2001-09-25 22:26 ` David S. Miller
2001-09-26 17:42 ` Ingo Molnar
2001-09-25 22:01 ` Andrea Arcangeli
2001-09-25 22:03 ` David S. Miller
2001-09-25 22:59 ` Andrea Arcangeli
2001-09-25 20:40 ` Josh MacDonald
2001-09-25 19:25 ` Marcelo Tosatti
2001-09-25 21:57 ` Andrea Arcangeli
-- strict thread matches above, loose matches on Subject: below --
2001-09-26 5:04 Dipankar Sarma
2001-09-26 5:31 ` Andrew Morton
2001-09-26 6:57 ` David S. Miller
2001-09-26 7:08 ` Dipankar Sarma
2001-09-26 16:52 ` John Hawkes
[not found] <fa.cbgmt3v.192gc8r@ifi.uio.no>
[not found] ` <fa.cd0mtbv.1aigc0v@ifi.uio.no>
[not found] ` <i1m66a5o1zc.fsf@verden.pvv.ntnu.no>
2001-09-27 1:34 ` Vojtech Pavlik
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