From: Andrew Morton <akpm@osdl.org>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: pj@sgi.com, linux-kernel@vger.kernel.org, ebiederm@xmission.com
Subject: Re: [RFC] ps command race fix
Date: Mon, 24 Jul 2006 19:33:18 -0700 [thread overview]
Message-ID: <20060724193318.d57983c1.akpm@osdl.org> (raw)
In-Reply-To: <20060725110835.59c13576.kamezawa.hiroyu@jp.fujitsu.com>
On Tue, 25 Jul 2006 11:08:35 +0900
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> > Then the seek and read and such semantics are nice and stable and
> > simple.
> >
> yes...
> I think snapshot at open() is okay.
We cannot do a single kmalloc() like cpuset does.
The kernel presently kind-of guarantees that a 32k kmalloc() will work,
although the VM might have to do very large amounts of work to achieve it.
But 32k is only 8192 processes, so a snapshot will need multiple
allocations and a list and trouble dropping and retaking tasklist_lock to
allocate memory and keeping things stable while doing that. I suspect
it'll end up ugly.
And it permits userspace to pin rather a lot of memory.
next prev parent reply other threads:[~2006-07-25 2:33 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-14 11:39 KAMEZAWA Hiroyuki
2006-07-25 1:20 ` Andrew Morton
2006-07-25 1:48 ` Paul Jackson
2006-07-25 2:00 ` Andrew Morton
2006-07-25 2:08 ` KAMEZAWA Hiroyuki
2006-07-25 2:33 ` Andrew Morton [this message]
2006-07-25 2:50 ` KAMEZAWA Hiroyuki
2006-07-25 3:16 ` KAMEZAWA Hiroyuki
2006-08-13 16:29 ` Eric W. Biederman
2006-08-13 17:34 ` Andrew Morton
2006-08-13 19:00 ` Eric W. Biederman
2006-08-13 19:12 ` Paul Jackson
2006-08-16 1:23 ` KAMEZAWA Hiroyuki
2006-08-17 4:59 ` Eric W. Biederman
2006-08-17 6:32 ` KAMEZAWA Hiroyuki
2006-08-17 13:39 ` Eric W. Biederman
2006-08-17 18:16 ` Jean Delvare
2006-08-18 0:21 ` KAMEZAWA Hiroyuki
2006-08-18 3:53 ` Eric W. Biederman
2006-08-13 20:08 ` Albert Cahalan
2006-08-16 2:20 ` Kyle Moffett
2006-07-25 7:22 ` Paul Jackson
2006-07-25 1:53 ` KAMEZAWA Hiroyuki
2006-07-25 2:06 ` Andrew Morton
2006-07-25 2:34 ` KAMEZAWA Hiroyuki
2006-07-25 6:09 ` Eric W. Biederman
2006-07-25 6:47 Albert Cahalan
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