One correction below. On Thu, Nov 3, 2011 at 11:55 AM, Lei Yu <y.benben.y@xxxxxxxxx> wrote: > Hi, > I tried to use cpufreq_stats to do some performance anlaysis but I > did not see cpufreq_stats entries under sysfs on my Linux machine. I > am wondering if anyone can help me point out what could be the > problem. > Here are more detailed info > 1). My kernel version is: 3.0.1 > 2). cpufreq and cpufreq_stats has been built into the kernel > image rather than as a separate, standalone kernel modules. > 3). I can see cpufreq related sysfs entries under: > /sys/devices/system/cpu/cpufreq and > /sys/devices/system/cpu/cpu0/cpufreq. > 4). But when I looked under above two directories, I did not > see cpufreq_stats related entries. > Also, when I looked at the code of the cpufreq_stats.c, I see the > logics like this: > --> cpufreq_stats sysfs is only created inside > cpufreq_stats_create_table() > --> cpufreq_stats_create_table() is either invoked inside > cpufreq_stat_notifier_policy() or cpufreq_stats_create_table_cpu(). > --> cpufreq_stats_create_table_cpu() is only invoked if a CPU > is CPU_DOWN_FAILED or CPU_DOWN_FAILED_FROZEN which will not happen in > my environment. > --> And, cpufreq_stats_init() will unregister > CPUFREQ_POLICY_NOTIFIER if registering of CPUFREQ_TRANSITION_NOTIFIER > is successful. > So, cpufreq_stats sysfs entries will not exist? I am sure I > have mis-read the code somehow. Please ignore my explanation of the code above since I missed the early return. > > Really appreciate your help. > > Lei Yu > > P.S. I am new to Linux kernel mailing list, if I am not following any > of the style, pls do let me know. > -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
