Joel Stanley <j...@jms.id.au> writes: > It's not done anything for a long time. Save the percpu variable, and > emit a warning to remind users to not expect it to do anything. > > Signed-off-by: Joel Stanley <j...@jms.id.au> > --- > arch/powerpc/kernel/sysfs.c | 41 +++++++++++++------------------------ > 1 file changed, 14 insertions(+), 27 deletions(-) > > diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c > index 571b3259697e..530ae92bc46d 100644 > --- a/arch/powerpc/kernel/sysfs.c > +++ b/arch/powerpc/kernel/sysfs.c > @@ -32,29 +32,25 @@ > > static DEFINE_PER_CPU(struct cpu, cpu_devices); > > -/* > - * SMT snooze delay stuff, 64-bit only for now > - */ > - > #ifdef CONFIG_PPC64 > > -/* Time in microseconds we delay before sleeping in the idle loop */ > -static DEFINE_PER_CPU(long, smt_snooze_delay) = { 100 }; > +/* > + * Snooze delay has not been hooked up since 3fa8cad82b94 > ("powerpc/pseries/cpuidle: > + * smt-snooze-delay cleanup.") and has been broken even longer. As was > foretold in > + * 2014: > + * > + * "ppc64_util currently utilises it. Once we fix ppc64_util, propose to > clean > + * up the kernel code." > + * > + * At some point in the future this code should be removed. > + */ > > static ssize_t store_smt_snooze_delay(struct device *dev, > struct device_attribute *attr, > const char *buf, > size_t count) > { > - struct cpu *cpu = container_of(dev, struct cpu, dev); > - ssize_t ret; > - long snooze; > - > - ret = sscanf(buf, "%ld", &snooze); > - if (ret != 1) > - return -EINVAL; > - > - per_cpu(smt_snooze_delay, cpu->dev.id) = snooze; > + WARN_ON_ONCE("smt_snooze_delay sysfs file has no effect\n");
We shouldn't have user-triggerable WARNs. I think this should just be a pr_warn_ratelimited(), maybe including current->comm & pid. cheers