From: "YOSHIFUJI Hideaki / 吉藤英明" <yoshfuji@linux-ipv6.org>
To: mfedyk@matchmail.com
Cc: jmorris@redhat.com, linux-kernel@vger.kernel.org,
yoshfuji@linux-ipv6.org
Subject: Re: sysctl vs /proc/sys
Date: Sat, 13 Dec 2003 09:42:10 +0900 (JST) [thread overview]
Message-ID: <20031213.094210.107050343.yoshfuji@linux-ipv6.org> (raw)
In-Reply-To: <20031212181517.GM15401@matchmail.com>
In article <20031212181517.GM15401@matchmail.com> (at Fri, 12 Dec 2003 10:15:17 -0800), Mike Fedyk <mfedyk@matchmail.com> says:
> On Fri, Dec 12, 2003 at 09:28:32AM -0500, James Morris wrote:
> > On Fri, 12 Dec 2003, YOSHIFUJI Hideaki / [iso-2022-jp] 吉藤英明 wrote:
> >
> > > Can we get the exact previous value from /proc/sys atomicly?
> >
> > I'm not sure what you mean by this.
>
> Read value and modify in one op?
Yes, I meant to read old value and to set new one in one system call.
The sysctl system-call does lock_kernel, so sysctl(2) sytem-call
are serialized.
How about procfs? Are there locks between multiple read-and-write?
Since It seems user-space cannot (or even should not) let kernel
hold lock(s) during read-and-write operation, procfs cannot be
the alternative.
Do I mis-understand something?
--yoshfuji
next prev parent reply other threads:[~2003-12-13 0:49 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-12-12 12:58 YOSHIFUJI Hideaki / 吉藤英明
2003-12-12 13:20 ` James Morris
2003-12-12 13:46 ` YOSHIFUJI Hideaki / 吉藤英明
2003-12-12 14:28 ` James Morris
2003-12-12 18:15 ` Mike Fedyk
2003-12-13 0:42 ` YOSHIFUJI Hideaki / 吉藤英明 [this message]
2003-12-13 1:31 ` H. Peter Anvin
2003-12-13 2:06 ` Linux Kernel 2.6.0-test11 VFS problem Ananda Bhattacharya
2003-12-13 2:30 ` Mike Fedyk
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