On 07/24/2013 05:07 PM, Viresh Kumar wrote:
I just realized I missed answering few questions:
On 24 July 2013 13:13, Chanwoo Choi cw00.choi@samsung.com wrote:
On 07/24/2013 02:05 PM, Viresh Kumar wrote:
On 24 July 2013 06:55, Chanwoo Choi cw00.choi@samsung.com wrote:
On 07/22/2013 07:11 PM, Viresh Kumar wrote:
On 18 July 2013 16:47, Chanwoo Choi cw00.choi@samsung.com wrote:
+static void cpufreq_move_debugfs_dir(struct cpufreq_policy *policy,
unsigned int new_cpu)+{
struct dentry *old_entry, *new_entry;char new_dir_name[CPUFREQ_NAME_LEN];unsigned int j, old_cpu = policy->cpu;if (!policy->cpu_debugfs[new_cpu])return;/** Remove symbolic link of debugfs directory except for debugfs* directory of old_cpu.*/for_each_present_cpu(j) {if (old_cpu == j)continue;debugfs_remove(policy->cpu_debugfs[j]);Why you need this? We aren't removing the earlier dentry at all here.
haven't answered this.
The debugfs entry of 'old_cpu' include child debugfs file(e.g., load_table) If cpu is last user of policy and core call __cpufre_remove_dev() to remove last cpu, core call cpufreq_move_debugfs_dir(). I have to move the data of debugfs directory/file and child data for 'old_cpu' to debugfs directory for 'new_cpu'.
If I remove earlier dentry of 'old_cpu', I can't get the child debugfs dir/file. So I didn't remove the earlier dentry of 'old_cpu'.
Okay.. The original question was: why do you need to remove & add entries or links for cpus other than policy->cpu? Because we are renaming the entry, wouldn't that work straight away?
In case that all CPUs share same cpufreq policy. Each debugfs dentry of CPU[1-3] except for CPU0 has symbolic link to CPU0's debugfs directory as following.
-sh-4.1# ls -al /sys/kernel/debug/cpufreq/ total 0 drwxr-xr-x 3 root root 0 Jan 1 09:00 . drwx------ 28 root root 0 Jan 1 09:00 .. drwxr-xr-x 2 root root 0 Jan 1 09:00 cpu0 (policy->cpu is 0) lrwxrwxrwx 1 root root 0 Jan 1 09:00 cpu1 -> ./cpu0 lrwxrwxrwx 1 root root 0 Jan 1 09:00 cpu2 -> ./cpu0 lrwxrwxrwx 1 root root 0 Jan 1 09:00 cpu3 -> ./cpu0
If turn off CPU0 state, I have to move debugfs directory data from cpu0 to cpu1 and again create link to cpu1's debugfs directory for CPU[2-3] debugfs directory. So, I removed dentry link of CPU[1-3] before creating link again.
cpu1 cpu2 -> ./cpu1 cpu3 -> ./cpu1
But I can rewrite new link of CPU[2-3] to previous dentry link(policy->cpu_debugfs[2] or policy->cpu_debugfs[3]) for reducing unnecessary code without revmoval sequence.