From: Jamie Lokier <jamie@shareable.org>
To: "Stephen C. Tweedie" <sct@redhat.com>
Cc: linux-mm <linux-mm@kvack.org>, Andrew Morton <akpm@osdl.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Ulrich Drepper <drepper@redhat.com>
Subject: Re: msync() behaviour broken for MS_ASYNC, revert patch?
Date: Wed, 21 Apr 2004 03:10:10 +0100 [thread overview]
Message-ID: <20040421021010.GC23621@mail.shareable.org> (raw)
In-Reply-To: <1082411657.2237.128.camel@sisko.scot.redhat.com>
Stephen C. Tweedie wrote:
> > If so, what was the change?
>
> 2.4.9 behaved like current 2.6 --- on MS_ASYNC, it did a
> set_page_dirty() which means the page will get picked up by the next
> 5-second bdflush pass. But later 2.4 kernels were changed so that they
> started MS_ASYNC IO immediately with filemap_fdatasync() (which is
> asynchronous regarding the new IO, but which blocks synchronously if
> there is already old IO in flight on the page.)
>
> That was reverted back to the earlier, 2.4.9 behaviour in the 2.5
> series.
It was 2.5.68.
Thanks, that's very helpful.
msync(0) has always had behaviour consistent with the <=2.4.9 and
>=2.5.68 MS_ASYNC behaviour, is that right?
If so, programs may as well "#define MS_ASYNC 0" on Linux, to get well
defined and consistent behaviour. It would be nice to change the
definition in libc to zero, but I don't think it's possible because
msync(MS_SYNC|MS_ASYNC) needs to fail.
-- Jamie
WARNING: multiple messages have this Message-ID (diff)
From: Jamie Lokier <jamie@shareable.org>
To: "Stephen C. Tweedie" <sct@redhat.com>
Cc: linux-mm <linux-mm@kvack.org>, Andrew Morton <akpm@osdl.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Ulrich Drepper <drepper@redhat.com>
Subject: Re: msync() behaviour broken for MS_ASYNC, revert patch?
Date: Wed, 21 Apr 2004 03:10:10 +0100 [thread overview]
Message-ID: <20040421021010.GC23621@mail.shareable.org> (raw)
In-Reply-To: <1082411657.2237.128.camel@sisko.scot.redhat.com>
Stephen C. Tweedie wrote:
> > If so, what was the change?
>
> 2.4.9 behaved like current 2.6 --- on MS_ASYNC, it did a
> set_page_dirty() which means the page will get picked up by the next
> 5-second bdflush pass. But later 2.4 kernels were changed so that they
> started MS_ASYNC IO immediately with filemap_fdatasync() (which is
> asynchronous regarding the new IO, but which blocks synchronously if
> there is already old IO in flight on the page.)
>
> That was reverted back to the earlier, 2.4.9 behaviour in the 2.5
> series.
It was 2.5.68.
Thanks, that's very helpful.
msync(0) has always had behaviour consistent with the <=2.4.9 and
>=2.5.68 MS_ASYNC behaviour, is that right?
If so, programs may as well "#define MS_ASYNC 0" on Linux, to get well
defined and consistent behaviour. It would be nice to change the
definition in libc to zero, but I don't think it's possible because
msync(MS_SYNC|MS_ASYNC) needs to fail.
-- Jamie
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next prev parent reply other threads:[~2004-04-21 2:10 UTC|newest]
Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-31 22:16 msync() behaviour broken for MS_ASYNC, revert patch? Stephen C. Tweedie
2004-03-31 22:37 ` Linus Torvalds
2004-03-31 22:37 ` Linus Torvalds
2004-03-31 23:41 ` Stephen C. Tweedie
2004-03-31 23:41 ` Stephen C. Tweedie
2004-04-01 0:08 ` Linus Torvalds
2004-04-01 0:08 ` Linus Torvalds
2004-04-01 0:30 ` Andrew Morton
2004-04-01 0:30 ` Andrew Morton
2004-04-01 15:40 ` Stephen C. Tweedie
2004-04-01 15:40 ` Stephen C. Tweedie
2004-04-01 16:02 ` Linus Torvalds
2004-04-01 16:02 ` Linus Torvalds
2004-04-01 16:33 ` Stephen C. Tweedie
2004-04-01 16:33 ` Stephen C. Tweedie
2004-04-01 16:19 ` Jamie Lokier
2004-04-01 16:19 ` Jamie Lokier
2004-04-01 16:56 ` s390 storage key inconsistency? [was Re: msync() behaviour broken for MS_ASYNC, revert patch?] Stephen C. Tweedie
2004-04-01 16:56 ` Stephen C. Tweedie
2004-04-01 16:57 ` msync() behaviour broken for MS_ASYNC, revert patch? Stephen C. Tweedie
2004-04-01 16:57 ` Stephen C. Tweedie
2004-04-01 18:51 ` Andrew Morton
2004-04-01 18:51 ` Andrew Morton
2004-03-31 22:53 ` Andrew Morton
2004-03-31 22:53 ` Andrew Morton
2004-03-31 23:20 ` Stephen C. Tweedie
2004-03-31 23:20 ` Stephen C. Tweedie
2004-04-16 22:35 ` Jamie Lokier
2004-04-16 22:35 ` Jamie Lokier
2004-04-19 21:54 ` Stephen C. Tweedie
2004-04-19 21:54 ` Stephen C. Tweedie
2004-04-21 2:10 ` Jamie Lokier [this message]
2004-04-21 2:10 ` Jamie Lokier
2004-04-21 9:52 ` Stephen C. Tweedie
2004-04-21 9:52 ` Stephen C. Tweedie
-- strict thread matches above, loose matches on Subject: below --
2006-02-09 7:18 linux
2006-02-09 8:18 ` Andrew Morton
2006-02-09 8:35 ` Nick Piggin
2006-02-09 8:42 ` Andrew Morton
2006-02-09 12:38 ` Nick Piggin
2006-02-09 12:39 ` Nick Piggin
2006-02-09 17:48 ` Andrew Morton
2006-02-10 3:36 ` Nick Piggin
2006-02-10 3:50 ` Andrew Morton
2006-02-10 3:57 ` Nick Piggin
2006-02-10 4:13 ` Andrew Morton
2006-02-10 4:30 ` Nick Piggin
2006-02-10 4:43 ` Andrew Morton
2006-02-10 4:52 ` Nick Piggin
2006-02-10 5:13 ` Andrew Morton
2006-02-10 5:29 ` Nick Piggin
2006-02-10 5:50 ` Andrew Morton
2006-02-10 6:03 ` Nick Piggin
2006-02-10 6:13 ` Andrew Morton
2006-02-10 6:31 ` Nick Piggin
2006-02-10 6:46 ` Andrew Morton
2006-02-10 6:57 ` Nick Piggin
2006-02-10 7:14 ` Andrew Morton
2006-02-10 12:41 ` Nick Piggin
2006-02-10 16:19 ` Linus Torvalds
2006-02-10 17:00 ` Nick Piggin
2006-02-10 17:12 ` Linus Torvalds
2006-02-10 17:35 ` Linus Torvalds
2006-02-10 17:59 ` Nick Piggin
2006-02-10 18:55 ` Linus Torvalds
2006-02-10 19:29 ` Nick Piggin
2006-02-10 19:44 ` Linus Torvalds
2006-02-10 19:52 ` Nick Piggin
2006-02-10 20:03 ` Linus Torvalds
2006-02-11 5:49 ` Nick Piggin
2006-02-10 16:05 ` Linus Torvalds
2006-02-10 16:37 ` Nick Piggin
2006-02-10 17:03 ` Linus Torvalds
2006-02-10 17:37 ` Nick Piggin
2006-02-10 18:01 ` Linus Torvalds
2006-02-10 18:38 ` Nick Piggin
2006-02-10 19:05 ` Linus Torvalds
2006-02-10 19:34 ` Oliver Neukum
2006-02-10 19:59 ` Linus Torvalds
2006-02-10 20:11 ` Andrew Morton
2006-02-10 21:15 ` Linus Torvalds
2006-02-10 21:28 ` Andrew Morton
2006-02-10 20:03 ` Nick Piggin
2006-02-10 21:10 ` Linus Torvalds
2006-02-10 21:55 ` Trond Myklebust
2006-02-10 22:46 ` Linus Torvalds
2006-02-10 23:02 ` Trond Myklebust
2006-02-10 23:15 ` Linus Torvalds
2006-02-11 19:07 ` Trond Myklebust
2006-02-10 17:29 ` linux
2006-02-10 17:42 ` Linus Torvalds
2006-02-10 18:57 ` Nick Piggin
2006-02-10 8:00 ` linux
2006-02-10 13:18 ` Nick Piggin
2006-02-10 7:15 ` linux
2006-02-10 7:28 ` Andrew Morton
2006-02-09 11:18 ` linux
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