Messages in this thread |  | | Date | Wed, 22 Oct 2014 16:58:04 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH v2 11/12] perf/x86: make HT bug workaround conditioned on HT enabled |
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On Thu, Oct 09, 2014 at 06:34:45PM +0200, Stephane Eranian wrote:
SNIP
> --- a/arch/x86/kernel/cpu/perf_event_intel.c > +++ b/arch/x86/kernel/cpu/perf_event_intel.c > @@ -12,6 +12,7 @@ > #include <linux/init.h> > #include <linux/slab.h> > #include <linux/export.h> > +#include <linux/watchdog.h> > > #include <asm/cpufeature.h> > #include <asm/hardirq.h> > @@ -1811,7 +1812,7 @@ intel_start_scheduling(struct cpu_hw_events *cpuc) > /* > * nothing needed if in group validation mode > */ > - if (cpuc->is_fake) > + if (cpuc->is_fake || !is_ht_workaround_enabled()) > return; > /* > * no exclusion needed > @@ -1849,8 +1850,9 @@ intel_stop_scheduling(struct cpu_hw_events *cpuc) > /* > * nothing needed if in group validation mode > */ > - if (cpuc->is_fake) > + if (cpuc->is_fake || !is_ht_workaround_enabled()) > return;
Is it possible to change is_ht_workaround_enabled() result within intel_start_scheduling and intel_stop_scheduling time frame? like following would happen:
is_ht_workaround_enabled == 1
intel_start_scheduling -> spin_lock(&excl_cntrs->lock);
# echo 0 > /sys/devices/cpu/ht_bug_workaround
is_ht_workaround_enabled == 0
intel_stop_scheduling -> wont call spin_unlock(&excl_cntrs->lock)
for some reason I can't get HT enabled on my HSW server, so I cannot try ;-)
jirka
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