cpufreq_update_policy() calls cpufreq_driver->get() to get current frequency of
a CPU and it is not supposed to fail or return zero. Return error in case that
happens.
Signed-off-by: Viresh Kumar <viresh.kumar(a)linaro.org>
---
V1->V2:
- Fixed return error to EIO instead of EINVAL
- Added WARN_ON() to flag get() failing and hence removed the print message as
well which was earlier printed during errors.
drivers/cpufreq/cpufreq.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index c755b5f..bf80502 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2139,6 +2139,11 @@ int cpufreq_update_policy(unsigned int cpu)
*/
if (cpufreq_driver->get) {
new_policy.cur = cpufreq_driver->get(cpu);
+ if (WARN_ON(!new_policy.cur)) {
+ ret = -EIO;
+ goto no_policy;
+ }
+
if (!policy->cur) {
pr_debug("Driver did not initialize current freq");
policy->cur = new_policy.cur;
--
1.7.12.rc2.18.g61b472e
Hi,
I am learning building arm64 kernel on:
https://wiki.linaro.org/HowTo/BuildArm64Kernel
I followed the page and started the kernel, because I didn't indicate a mmc
deivce,
the console outputs as below:
VFS: Cannot open root device "vda2" or unknown-block(254,2): error -6
Please append a correct "root=" boot option; here are the available
partitions:
Kernel panic - not syncing: VFS: Unable to mount root fs on
unknown-block(254,2)
I had download the pre-built root filesystem, but I don't know how to use
it.
Could anyone tell me how to mount rootfs? Thank you!
--
Regards,
Zhi-zhou
The cpu_load decays on time according past cpu load of rq. The sched_avg also decays tasks' load on time. Now we has 2 kind decay for cpu_load. That is a kind of redundancy. And increase the system load by decay calculation. This patch try to remove the cpu_load decay.
There are 5 load_idx used for cpu_load in sched_domain. busy_idx and idle_idx are not zero usually, but newidle_idx, wake_idx and forkexec_idx are all zero on every arch. A shortcut to remove cpu_Load decay in the first patch. just one line patch for this change.
V2,
1, This version do some tuning on load bias of target load, to maximum match current code logical.
2, Got further to remove the cpu_load in rq.
3, Revert the patch 'Limit sd->*_idx range on sysctl' since no needs
Any testing/comments are appreciated.
This patch rebase on latest tip/master.
The git tree for this patchset at:
git@github.com:alexshi/power-scheduling.git noload
Thanks
Alex
