On Mon, 2008-08-04 at 22:52 +0200, John Kacur wrote: > Even after applying some fixes posted by Chirag and Peter Z, I'm still > getting some messages in my log like this > BUG: sleeping function called from invalid context swapper(0) at > kernel/rtmutex.c:743 > in_atomic():1 [00000001], irqs_disabled():1 > Pid: 0, comm: swapper Tainted: G W 2.6.26.1-rt1.jk #2 > > Call Trace: > [<ffffffff802305d3>] __might_sleep+0x12d/0x132 > [<ffffffff8046cdbe>] __rt_spin_lock+0x34/0x7d > [<ffffffff8046ce15>] rt_spin_lock+0xe/0x10 > [<ffffffff802532e5>] pm_qos_requirement+0x1f/0x3c > [<ffffffff803e1b7f>] menu_select+0x7b/0x9c > [<ffffffff8020b1be>] ? default_idle+0x0/0x5a > [<ffffffff8020b1be>] ? default_idle+0x0/0x5a > [<ffffffff803e0b4b>] cpuidle_idle_call+0x68/0xd8 > [<ffffffff803e0ae3>] ? cpuidle_idle_call+0x0/0xd8 > [<ffffffff8020b1be>] ? default_idle+0x0/0x5a > [<ffffffff8020b333>] cpu_idle+0xb2/0x12d > [<ffffffff80466af0>] start_secondary+0x186/0x18b > > --------------------------- > | preempt count: 00000001 ] > | 1-level deep critical section nesting: > ---------------------------------------- > ... [<ffffffff8020b39c>] .... cpu_idle+0x11b/0x12d > ......[<ffffffff80466af0>] .. ( <= start_secondary+0x186/0x18b) > > The following simple patch makes the messages disappear - however, > there may be a better more fine grained solution, but the problem is > also that all the functions are designed to use the same lock. Hmm, I think you're right - its called from the idle routine so we can't go about sleeping there. The only trouble I have is with kernel/pm_qos_params.c:update_target()'s use of this lock - that is decidedly not O(1). Mark, would it be possible to split that lock in two, one lock protecting pm_qos_array[], and one lock protecting the requirements.list ? [ NOTE: this is the -rt kernel we're talking about ] > Signed-off-by: John Kacur <jkacur at gmail dot com> > > Index: linux-2.6.26.1-jk-rt1/kernel/pm_qos_params.c > =================================================================== > --- linux-2.6.26.1-jk-rt1.orig/kernel/pm_qos_params.c > +++ linux-2.6.26.1-jk-rt1/kernel/pm_qos_params.c > @@ -110,7 +110,7 @@ static struct pm_qos_object *pm_qos_arra > &network_throughput_pm_qos > }; > > -static DEFINE_SPINLOCK(pm_qos_lock); > +static DEFINE_RAW_SPINLOCK(pm_qos_lock); > > static ssize_t pm_qos_power_write(struct file *filp, const char > __user *buf, > size_t count, loff_t *f_pos); > -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
