Messages in this thread | | | Date | Tue, 22 Jan 2013 15:22:43 +0100 | Subject | Re: [PATCH v6 03/18] perf/x86: add flags to event constraints | From | Stephane Eranian <> |
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On Fri, Jan 18, 2013 at 11:59 PM, Andi Kleen <ak@linux.intel.com> wrote: >> --- a/arch/x86/kernel/cpu/perf_event_intel.c >> +++ b/arch/x86/kernel/cpu/perf_event_intel.c >> @@ -1367,8 +1367,10 @@ x86_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event) >> >> if (x86_pmu.event_constraints) { >> for_each_event_constraint(c, x86_pmu.event_constraints) { >> - if ((event->hw.config & c->cmask) == c->code) >> + if ((event->hw.config & c->cmask) == c->code) { >> + event->hw.flags |= c->flags; >> return c; >> + } > > It's not fully clear where that hw.flags field gets initially zeroed. Is that implicit > in the allocation? Some comments would be good about its live cycle. > Yes, this is by allocation. I used |= in case we need to add more flags in the future. I will add a comment.
> Or just use a = instead of |=? Why would you have multiple flags in different places? > > -Andi
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