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.
pm_qos_requirement-fix 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);
