| Message ID | 85e5b1e6e871fdd8e7a80bba310a7b2948b52917.1420177186.git.viresh.kumar@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 4 January 2015 at 03:28, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > On Friday, January 02, 2015 11:16:39 AM Viresh Kumar wrote: >> __cpufreq_stats_create_table() is called from: >> - policy create notifier: stats will always be NULL here >> - cpufreq_stats_init() calls it for all CPUs as cpufreq-stats can be initialized >> after cpufreq driver. Because CPUs share clock lines, 'stats' will be NULL >> here for the first cpu only and will return back for others. >> >> While we return for other CPUs, we don't return the right error value. We must >> return -EEXIST, as that is the case here. > > What exactly is wrong with -EBUSY, then? Its not that could would fail with EBUSY but this is what I thought. Generally: - Returning EBUSY means: we are busy right not try again. And that might be immediate. - Returning EEXIST means: We already have what you are trying to create and there is no need to create it again, and so no more tries are required. That's all.. -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 6 January 2015 at 05:22, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > Now note how much useful the above is than the stuff in your original changelog. Yes, its all in logs now :) > I'd say all depends on whether or not the callers deal with the error code > appropriately. If it is propagated all the way to user space, it really should > *not* be -EBUSY, but otherwise this is a matter of how the callers handle the > given error code. It might not get propagated to user space for now, but not sure if that wouldn't change in future. Even if it stays only within the kernel, we better return the error codes that fit the best for a particular situation and so I would still like to get this through. -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c index 81be4d637ab4..403671b1a5ee 100644 --- a/drivers/cpufreq/cpufreq_stats.c +++ b/drivers/cpufreq/cpufreq_stats.c @@ -192,8 +192,10 @@ static int __cpufreq_stats_create_table(struct cpufreq_policy *policy) if (unlikely(!table)) return 0; + /* stats already initialized */ if (per_cpu(cpufreq_stats_table, cpu)) - return -EBUSY; + return -EEXIST; + stat = kzalloc(sizeof(*stat), GFP_KERNEL); if ((stat) == NULL) return -ENOMEM;