From: Albert Cahalan <albert@users.sf.net>
To: Ingo Molnar <mingo@elte.hu>
Cc: linux-kernel mailing list <linux-kernel@vger.kernel.org>,
wli@holomorphy.com, cw@f00f.org, anton@samba.org
Subject: Re: /proc/sys/kernel/pid_max issues
Date: 13 Sep 2004 09:54:09 -0400 [thread overview]
Message-ID: <1095083649.1174.1293.camel@cube> (raw)
In-Reply-To: <20040913075743.GA15722@elte.hu>
On Mon, 2004-09-13 at 03:57, Ingo Molnar wrote:
> * Albert Cahalan <albert@users.sf.net> wrote:
>
> > I'd much prefer LRU allocation. There are
> > lots of system calls that take PID values.
> > All such calls are hazardous. They're pretty
> > much broken by design.
>
> this is a pretty sweeping assertion. Would you
> care to mention a few examples of such hazards?
kill(12345,9)
setpriority(PRIO_PROCESS,12345,-20)
sched_setscheduler(12345, SCHED_FIFO, &sp)
Prior to the call being handled, the process may
die and be replaced. Some random innocent process,
or a not-so-innocent one, will get acted upon by
mistake. This is broken and dangerous.
Well, it's in the UNIX standard. The best one can
do is to make the race window hard to hit, with LRU.
> > BTW, since pid_max is now adjustable, reducing
> > the default to 4 digits would make sense. [...]
>
> i'm not sure what you mean by 'now', pid_max has
> been adjustable for quite some time.
2.6.x series I believe, not 2.4.xx series
next prev parent reply other threads:[~2004-09-13 13:57 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-13 3:20 /proc/sys/kernel/pid_max issues Albert Cahalan
2004-09-13 7:42 ` William Lee Irwin III
2004-09-13 14:11 ` Albert Cahalan
2004-09-13 14:27 ` William Lee Irwin III
2004-09-13 14:51 ` Herbert Poetzl
2004-09-14 2:13 ` William Lee Irwin III
2004-09-23 13:13 ` Pavel Machek
2004-09-24 16:02 ` Martin Mares
2004-09-23 13:11 ` Pavel Machek
2004-09-13 7:57 ` Ingo Molnar
2004-09-13 13:54 ` Albert Cahalan [this message]
2004-09-13 14:24 ` William Lee Irwin III
2004-09-13 14:54 ` Albert Cahalan
2004-09-14 2:02 ` William Lee Irwin III
2004-09-14 15:32 ` Ingo Molnar
2004-09-18 18:32 ` Pavel Machek
2004-09-23 13:18 ` Pavel Machek
-- strict thread matches above, loose matches on Subject: below --
2004-09-12 8:56 Anton Blanchard
2004-09-12 9:36 ` William Lee Irwin III
2004-09-12 9:51 ` Ingo Molnar
2004-09-12 9:58 ` William Lee Irwin III
2004-09-12 10:10 ` William Lee Irwin III
2004-09-12 10:13 ` Ingo Molnar
2004-09-12 10:43 ` William Lee Irwin III
2004-09-12 10:45 ` William Lee Irwin III
2004-09-12 11:08 ` William Lee Irwin III
2004-09-12 11:20 ` Ingo Molnar
2004-09-12 17:13 ` William Lee Irwin III
2004-09-12 18:02 ` Chris Wedgwood
2004-09-12 23:06 ` William Lee Irwin III
2004-09-12 9:39 ` Ingo Molnar
2004-09-12 9:43 ` William Lee Irwin III
2004-09-12 12:18 ` Arjan van de Ven
2004-09-12 12:30 ` Anton Blanchard
2004-09-12 12:44 ` Arjan van de Ven
2004-09-12 13:34 ` Anton Blanchard
2004-09-12 13:41 ` Ingo Molnar
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