From: Alexander Nyberg <alexn@dsv.su.se>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Livelock with the shmctl04 test program from linux test project
Date: Thu, 28 Oct 2004 12:59:05 +0200 [thread overview]
Message-ID: <1098961145.787.7.camel@boxen> (raw)
In-Reply-To: <41794334.1080206@colorfullife.com>
> Hi Alexander,
>
> >I'm seeing some sort of livelock on my dual amd64 with the shmctl04 test program
> >
> What do you mean with "sort of livelock"? Does it recover after a few
> minutes, does it recover if you send a signal to the shmctl04 test app?
> What is the contents of /proc/sysvipc/shm while xfce4 is running/not
> running?
Sorry for late reply, but I just can't understand why & how this happens, been trying to grasp
the IPC/SHM part but I'm missing something. One processor gets locked up and never released.
I did:
printk("taking lock\n");
spin_lock(&info->lock);
printk("lock taken\n");
and it never prints out "lock taken" so i know where it locks up. Now the fun part,
spinlock debugging doesn't catch it, but I did a simple patch to show who is holding a lock
at the current time, and it appears noone has taken the lock. I really don't get this.
With xfce4 running:
key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime
0 32768 1600 393216 629 608 2 1000 1000 1000 1000 1098960009 0 1098960009
0 65537 1600 196608 644 608 2 1000 1000 1000 1000 1098960009 0 1098960009
0 98306 1600 393216 646 668 2 1000 1000 1000 1000 1098960014 1098960014 1098960009
0 131075 1600 393216 648 608 2 1000 1000 1000 1000 1098960021 0 1098960021
0 163844 1600 393216 666 700 2 1000 1000 1000 1000 1098960029 1098960029 1098960023
0 196613 1600 196608 666 700 2 1000 1000 1000 1000 1098960029 1098960029 1098960023
0 229382 1600 393216 643 608 2 1000 1000 1000 1000 1098960023 0 1098960023
0 262151 1600 393216 668 681 2 1000 1000 1000 1000 1098960025 1098960025 1098960025
0 294920 1600 196608 648 608 2 1000 1000 1000 1000 1098960026 0 1098960026
0 360457 1600 393216 706 711 2 1000 1000 1000 1000 1098960036 1098960036 1098960035
0 425994 1600 393216 715 716 2 1000 1000 1000 1000 1098960039 1098960084 1098960039
0 458763 1600 196608 715 608 2 1000 1000 1000 1000 1098960041 0 1098960041
0 491532 1600 393216 642 608 2 1000 1000 1000 1000 1098960059 0 1098960059
Console only:
key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime
next prev parent reply other threads:[~2004-10-28 10:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-22 17:28 Livelock with the shmctl04 test program from linux test project Manfred Spraul
2004-10-28 10:59 ` Alexander Nyberg [this message]
2004-10-28 17:21 ` Manfred Spraul
-- strict thread matches above, loose matches on Subject: below --
2004-10-20 16:18 Alexander Nyberg
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