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From: Valdis.Kletnieks@vt.edu
To: Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Subject: [2.6.34 PATCH] kernel: fix exit message for dead process
Date: Thu, 20 May 2010 14:17:40 -0400	[thread overview]
Message-ID: <10672.1274379460@localhost> (raw)
In-Reply-To: Your message of "Thu, 20 May 2010 08:55:20 EDT." <20100520085520.5176d13c.akpm@linux-foundation.org>

If a process is exiting with a non-zero preempt_count, it's in fact almost
certainly going to fail to do so because it is exiting due to a BUG or OOPS
while it held a lock, at which point it will never actually exit.  So change
the message to say it attempted to do so, rather than implying it succeeded.
Problem spotted when a process BUG'ed, the kernel reported the 'exited' status,
and then proceeded to BUG twice more dealing with the now-zombied process:

> [   35.357018] note: keymap[2481] exited with preempt_count 1
> [   35.360503] BUG: scheduling while atomic: keymap/2481/0x10000002

Yes, one line is 83 characters. It's still more readable than a split printk.

Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>

--- linux-2.6.34-mmotm0519/kernel/exit.c.dist	2010-05-20 10:59:11.646870592 -0400
+++ linux-2.6.34-mmotm0519/kernel/exit.c	2010-05-20 14:05:16.068800223 -0400
@@ -936,7 +936,7 @@ NORET_TYPE void do_exit(long code)
 	raw_spin_unlock_wait(&tsk->pi_lock);
 
 	if (unlikely(in_atomic()))
-		printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",
+		printk(KERN_INFO "note: %s[%d] tried to exit with preempt_count %d\n",
 				current->comm, task_pid_nr(current),
 				preempt_count());
 


  parent reply	other threads:[~2010-05-20 18:17 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-05-19 23:13 mmotm 2010-05-19-16-12 uploaded akpm
2010-05-20 15:21 ` mmotm 2010-05-19 - Kconfig dependency list from hell Valdis.Kletnieks
2010-05-20 15:47 ` mmotm 2010-05-19 BUG weirdness Valdis.Kletnieks
2010-05-20 12:55   ` Andrew Morton
2010-05-20 16:45     ` Dmitry Torokhov
2010-05-20 17:52     ` Valdis.Kletnieks
2010-05-20 18:17     ` Valdis.Kletnieks [this message]
2010-05-20 18:36       ` [2.6.34 PATCH] kernel: fix exit message for dead process Andrew Morton
2010-05-20 21:08 ` [PATCH -mmotm] media: ak881x needs slab.h Randy Dunlap
2010-06-01  6:04   ` Ingo Molnar
2010-05-20 21:08 ` [PATCH -mmotm] backlight: fix s6e63m0 kconfig Randy Dunlap
2010-05-20 21:08 ` [PATCH -mmotm] backlight: fix s6e63m0 device attr function return types Randy Dunlap

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