Re: [BUG] warning at kernel/cpu.c:38/lock_cpu_hotplug()

Dave Jones
2006-09-23T18:11:05Z

On Sat, Sep 23, 2006 at 12:36:34PM +0300, S.Çağlar Onur wrote:
> 23 Eyl 2006 Cts 02:13 tarihinde, Dave Jones şunları yazmıştı:
> > On Sat, Sep 23, 2006 at 01:45:16AM +0300, S.Çağlar Onur wrote:
> > > Hi;
> > >
> > > With kernel-2.6.18, "modprobe cpufreq_stats" always (i can reproduce)
> > > gaves following;
> > >
> > > ...
> > > Lukewarm IQ detected in hotplug locking
> > > BUG: warning at kernel/cpu.c:38/lock_cpu_hotplug()
> > > [<b0134a42>] lock_cpu_hotplug+0x42/0x65
> > > [<b02f8af1>] cpufreq_update_policy+0x25/0xad
> > > [<b0358756>] kprobe_flush_task+0x18/0x40
> > > [<b0355aab>] schedule+0x63f/0x68b
> > > [<b01377c2>] __link_module+0x0/0x1f
> > > [<b0119e7d>] __cond_resched+0x16/0x34
> > > [<b03560bf>] cond_resched+0x26/0x31
> > > [<b0355b0e>] wait_for_completion+0x17/0xb1
> > > [<f965c547>] cpufreq_stat_cpu_callback+0x13/0x20 [cpufreq_stats]
> > > [<f9670074>] cpufreq_stats_init+0x74/0x8b [cpufreq_stats]
> > > [<b0137872>] sys_init_module+0x91/0x174
> > > [<b0102c81>] sysenter_past_esp+0x56/0x79
> >
> > This should do the trick.
> > I'll merge the same patch into cpufreq.git
>
> What about cpufreq_stats_exit, it has same locking? Seems like rmmod may cause
> same problem or im totaly wrong?

The CPU_DEAD notifier doesn't take the lock, so it's safe.

Dave