From: Robert Love <rml@tech9.net>
To: Haoqiang Zheng <hzheng@cs.columbia.edu>
Cc: linux-kernel@vger.kernel.org
Subject: Re: linux hangs with printk on schedule()
Date: 03 Feb 2003 19:43:52 -0500 [thread overview]
Message-ID: <1044319431.783.113.camel@phantasy> (raw)
In-Reply-To: <05db01c2cbe5$4b4c34f0$9c2a3b80@zhengthinkpad>
On Mon, 2003-02-03 at 19:35, Haoqiang Zheng wrote:
> I found Linux hangs when printk is inserted to the function schedule().
> Sure, it doesn't make much sense to add such a line to schedule(). But Linux
> shouldn't hang anyway, right? It's assumed that printk can be inserted
> safely to anywhere. So, is it a bug of Linux?
Its a known deadlock in 2.4:
schedule -> printk() -> dmesg output -> klogd wakes up -> repeat
It is not a hard fix and its basically one of a few places where you
cannot call printk(), which is otherwise a very robust funciton.
Robert Love
next prev parent reply other threads:[~2003-02-04 0:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-02-04 0:35 linux hangs with printk on schedule() Haoqiang Zheng
2003-02-04 0:43 ` Robert Love [this message]
[not found] <05db01c2cbe5$4b4c34f0$9c2a3b80@zhengthinkpad.suse.lists.linux.kernel>
2003-02-04 0:48 ` Andi Kleen
-- strict thread matches above, loose matches on Subject: below --
2003-02-05 3:01 Haoqiang Zheng
2003-02-06 2:18 ` Rick Lindsley
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