On 08/10/2015 07:11 AM, Stewart Smith wrote:
> Shilpasri G Bhat <shilpa.b...@linux.vnet.ibm.com> writes:
>> diff --git a/drivers/cpufreq/powernv-cpufreq.c
>> b/drivers/cpufreq/powernv-cpufreq.c
>> index d0c18c9..a634199 100644
>> --- a/drivers/cpufreq/powernv-cpufreq.c
>> +++ b/drivers/cpufreq/powernv-cpufreq.c
>> @@ -33,6 +33,7 @@
>> #include <asm/firmware.h>
>> #include <asm/reg.h>
>> #include <asm/smp.h> /* Required for cpu_sibling_mask() in UP configs */
>> +#include <asm/opal.h>
>>
>> #define POWERNV_MAX_PSTATES 256
>> #define PMSR_PSAFE_ENABLE (1UL << 30)
>> @@ -41,7 +42,7 @@
>> #define PMSR_LP(x) ((x >> 48) & 0xFF)
>>
>> static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
>> -static bool rebooting, throttled;
>> +static bool rebooting, throttled, occ_reset;
>>
>> static struct chip {
>> unsigned int id;
>> @@ -414,6 +415,74 @@ static struct notifier_block powernv_cpufreq_reboot_nb
>> = {
>> .notifier_call = powernv_cpufreq_reboot_notifier,
>> };
>>
>> +static char throttle_reason[][30] = {
>> + "No throttling",
>> + "Power Cap",
>> + "Processor Over Temperature",
>> + "Power Supply Failure",
>> + "Over Current",
>> + "OCC Reset"
>> + };
>> +
>> +static int powernv_cpufreq_occ_msg(struct notifier_block *nb,
>> + unsigned long msg_type, void *_msg)
>> +{
>> + struct opal_msg *msg = _msg;
>> + struct opal_occ_msg omsg;
>> +
>> + if (msg_type != OPAL_MSG_OCC)
>> + return 0;
>> +
>> + omsg.type = be64_to_cpu(msg->params[0]);
>> +
>> + switch (omsg.type) {
>> + case OCC_RESET:
>> + occ_reset = true;
>> + /*
>> + * powernv_cpufreq_throttle_check() is called in
>> + * target() callback which can detect the throttle state
>> + * for governors like ondemand.
>> + * But static governors will not call target() often thus
>> + * report throttling here.
>> + */
>> + if (!throttled) {
>> + throttled = true;
>> + pr_crit("CPU Frequency is throttled\n");
>> + }
>> + pr_info("OCC: Reset\n");
>> + break;
>> + case OCC_LOAD:
>> + pr_info("OCC: Loaded\n");
>> + break;
>
> I wonder if we could have the log messages be a bit clearer here, odds
> are, unless you're one of the people reading this code, you have no idea
> what an OCC is or what on earth "OCC: Loaded" means and why this
> *doesn't* mean that your CPUs are no longer throttled so that your
> computer doesn't catch fire/break/add 1+1 and get 4.
>
> Also, do we export this information via sysfs somewhere? It would seem
> to want to go along with other cpufreq/cpu info there.
No we don't export the throttling status of the cpu via sysfs. Since the
throttling state is common across the chip, the per_cpu export will be
redundant. Did you mean something like one of the below:
1)/sys/devices/system/cpu/cpufreq/chipN_throttle
2)/sys/devices/system/cpu/cpuN/cpufreq/throttle
>
> It feels like we could do much better at informing users as to what is
> going on.... maybe something like:
>
> "OCC (On Chip Controller - enforces hard thermal/power limits) Resetting: CPU
> frequency throttled for duration"
> "OCC Loading, CPU frequency throttled until OCC started"
> "OCC Active, CPU frequency no longer throttled"
>
Okay will change the messages.
Thanks and Regards,
Shilpa
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
