On Wed, Sep 12, 2012 at 4:38 PM, Peter Zijlstra <[email protected]> wrote: > On Wed, 2012-09-12 at 16:33 +0200, Stephane Eranian wrote: > >> >> If I do: >> for_each_possible_cpu(cpu) { >> cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); >> hr = &cpuctx->hrtimer; >> hrtimer_init(hr) >> } >> I don't understand why I would have to refer to per-cpu data >> (hrtimer_bases) from >> a CPU that is not equal to "cpu" here. Unless you're telling me it's >> read-only data. > > No its not read only, but it is unused until you do *hrtimer_start*(), > which will test and fix. > >> But still if it's per-cpu why not initialize with the correct CPU from >> the start? > > To keep the interface simpler I guess. There's no great harm in your > proposal, but it is strictly speaking superfluous. I'm not sure the max > one time avoidance of a base swizzle is worth the extra interface, I'll > leave that up to Thomas. > > Also, what Eric said ;-)
I am fine with dropping this patch. I just found it odd there was a per-cpu data reference embedded deep into the call. I wanted things to be more explicit. I know it works without the proposed change. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
