On Wednesday, February 06, 2013 10:11:25 PM Rafael J. Wysocki wrote:
> On Thursday, February 07, 2013 12:25:13 AM Artem Savkov wrote:
> > I get the following BUG on suspend using systemd-sleep(this doesn't
> > happen with pm-suspend). This seems to be introduced by some of the
> > Viresh's patches.
>
> Which branch from which day?
OK, I've reproduced it and the appended patch fixes it for me. Can you please
try it and report back?
Rafael
---
From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Subject: cpufreq: Move sysfs_remove_link() from under a spinlock
Commit 73bf0fc "cpufreq: Don't remove sysfs link for policy->cpu"
attempted to fix a bug in __cpufreq_remove_dev() by avoiding to
remove the link to the "cpufreq" directory for policy->cpu, but it
rearranged the code in such a way that sysfs_remove_link() ended up
under a spinlock, which caused complaints about sleeping in atomic
context to be emitted into the kernel log during system suspend.
To fix this, revert commit 73bf0fc partially and move the
sysfs_remove_link() in question to a separate block executed for
cpus > 1 outside of the spinlock.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/cpufreq.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
Index: test/drivers/cpufreq/cpufreq.c
===================================================================
--- test.orig/drivers/cpufreq/cpufreq.c
+++ test/drivers/cpufreq/cpufreq.c
@@ -1058,9 +1058,7 @@ static int __cpufreq_remove_dev(struct d
cpus = cpumask_weight(data->cpus);
cpumask_clear_cpu(cpu, data->cpus);
- if (cpu != data->cpu) {
- sysfs_remove_link(&dev->kobj, "cpufreq");
- } else if (cpus > 1) {
+ if (unlikely(cpu == data->cpu && cpus > 1)) {
/* first sibling now owns the new sysfs dir */
cpu_dev = get_cpu_device(cpumask_first(data->cpus));
sysfs_remove_link(&cpu_dev->kobj, "cpufreq");
@@ -1085,9 +1083,14 @@ static int __cpufreq_remove_dev(struct d
pr_debug("%s: removing link, cpu: %d\n", __func__, cpu);
cpufreq_cpu_put(data);
unlock_policy_rwsem_write(cpu);
-
- /* If cpu is last user of policy, free policy */
- if (cpus == 1) {
+ if (cpus > 1) {
+ sysfs_remove_link(&dev->kobj, "cpufreq");
+ if (cpufreq_driver->target) {
+ __cpufreq_governor(data, CPUFREQ_GOV_START);
+ __cpufreq_governor(data, CPUFREQ_GOV_LIMITS);
+ }
+ } else {
+ /* If cpu is the last user of policy, free policy */
lock_policy_rwsem_write(cpu);
kobj = &data->kobj;
cmp = &data->kobj_unregister;
@@ -1110,9 +1113,6 @@ static int __cpufreq_remove_dev(struct d
free_cpumask_var(data->related_cpus);
free_cpumask_var(data->cpus);
kfree(data);
- } else if (cpufreq_driver->target) {
- __cpufreq_governor(data, CPUFREQ_GOV_START);
- __cpufreq_governor(data, CPUFREQ_GOV_LIMITS);
}
return 0;
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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