Messages in this thread | | | From | Stephane Eranian <> | Date | Mon, 15 Apr 2019 10:20:57 -0700 | Subject | Re: [PATCH v2 2/2] perf/x86/intel: force resched when TFA sysctl is modified |
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On Mon, Apr 15, 2019 at 8:57 AM Peter Zijlstra <peterz@infradead.org> wrote: > > On Mon, Apr 08, 2019 at 10:32:52AM -0700, Stephane Eranian wrote: > > +static ssize_t set_sysctl_tfa(struct device *cdev, > > + struct device_attribute *attr, > > + const char *buf, size_t count) > > +{ > > + bool val; > > + ssize_t ret; > > + > > + ret = kstrtobool(buf, &val); > > + if (ret) > > + return ret; > > + > > + /* no change */ > > + if (val == allow_tsx_force_abort) > > + return count; > > + > > + allow_tsx_force_abort = val; > > + > > + get_online_cpus(); > > + on_each_cpu(update_tfa_sched, NULL, 1); > > + put_online_cpus(); > > + > > + return count; > > +} > > So we care about concurrent writing to that file? Not likely but we care about seeing the effects on event scheduling before the sysctl returns.
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