On Friday, October 25, 2013 11:28:02 AM Rafael J. Wysocki wrote:
> On Friday, October 25, 2013 10:02:22 AM Linus Torvalds wrote:
> > Adding more people, so quoting the whole email for them.
> >
> > We definitely have some module unload issues. Guys, try the following
> > a few times to unload modules:
> >
> > lsmod | grep ' 0 '| cut -d' ' -f1 | xargs sudo rmmod
> >
> > (a few times because unloading one module will then potentially make
> > other modules unloadable).
> >
> > On my machine, I can trigger this, for example:
> >
> > ------------[ cut here ]------------
> > WARNING: CPU: 0 PID: 3217 at fs/sysfs/file.c:498 sysfs_attr_ns+0x91/0xa0()
> > sysfs: kobject (null) without dirent
> > Modules linked in: fuse nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT xt_$
> > CPU: 0 PID: 3217 Comm: rmmod Not tainted 3.12.0-rc6-00284-ge6036c0b8896 #19
> > Hardware name: Sony Corporation SVP11213CXB/VAIO, BIOS R0270V7 05/17/2013
> > 0000000000000009 ffff8800aca35df8 ffffffff8160aab5 ffff8800aca35e40
> > ffff8800aca35e30 ffffffff810514b8 ffffffffa013f080 ffff8801194a6040
> > 0000000000000800 0000000000000000 0000000000c5b3e0 ffff8800aca35e90
> > Call Trace:
> > [<ffffffff8160aab5>] dump_stack+0x45/0x56
> > [<ffffffff810514b8>] warn_slowpath_common+0x78/0xa0
> > [<ffffffff81051527>] warn_slowpath_fmt+0x47/0x50
> > [<ffffffff810b5960>] ? module_refcount+0xb0/0xb0
> > [<ffffffff811e5c61>] sysfs_attr_ns+0x91/0xa0
> > [<ffffffff811e5d2a>] sysfs_remove_file+0x1a/0x50
> > [<ffffffff814c88a3>] cpufreq_sysfs_remove_file+0x13/0x30
> > [<ffffffffa013d350>] acpi_cpufreq_exit+0x2e/0xcde [acpi_cpufreq]
> > [<ffffffff810b7d1d>] SyS_delete_module+0x15d/0x2c0
> > [<ffffffff81002929>] ? do_notify_resume+0x59/0x90
> > [<ffffffff81618f62>] system_call_fastpath+0x16/0x1b
> > ---[ end trace f887112caaa5c4ab ]---
> >
> > so at least we have a cpufreq/sysfs interaction bug. There may be others.
> >
> > This particular cpufreq issue may be triggered by the fact that
> > acpi-cpufreq isn't actually in use (pstate is). Or it might be some
> > generic cpufreq/sysfs bug. Rafael, Greg, ideas?
>
> I *think* that this indeed is related to acpi-cpufreq being unused. That said,
> we've been fixing sysfs-related bugs in cpufreq recently and we may have
> overlooked something.
>
> I'll have a deeper look at that.
Well, if the ACPI cpufreq driver is not registered, the exit function of the
module shouldn't try to unregister it, so I have the appended patch (untested)
to fix that particular thing.
Rafael
---
drivers/cpufreq/acpi-cpufreq.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
Index: linux-pm/drivers/cpufreq/acpi-cpufreq.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/acpi-cpufreq.c
+++ linux-pm/drivers/cpufreq/acpi-cpufreq.c
@@ -982,6 +982,8 @@ static void __exit acpi_cpufreq_boost_ex
}
}
+static bool driver_registered;
+
static int __init acpi_cpufreq_init(void)
{
int ret;
@@ -1021,10 +1023,12 @@ static int __init acpi_cpufreq_init(void
#endif
ret = cpufreq_register_driver(&acpi_cpufreq_driver);
- if (ret)
+ if (ret) {
free_acpi_perf_data();
- else
+ } else {
acpi_cpufreq_boost_init();
+ driver_registered = true;
+ }
return ret;
}
@@ -1032,6 +1036,8 @@ static int __init acpi_cpufreq_init(void
static void __exit acpi_cpufreq_exit(void)
{
pr_debug("acpi_cpufreq_exit\n");
+ if (!driver_registered)
+ return;
acpi_cpufreq_boost_exit();
--
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