Messages in this thread | | | Date | Fri, 19 Feb 2016 23:01:59 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH v4 2/2] powercap/rapl: reduce ipi calls |
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On Fri, 19 Feb 2016, Thomas Gleixner wrote:
> On Fri, 19 Feb 2016, Jacob Pan wrote: > > @@ -1380,6 +1375,7 @@ static int rapl_detect_topology(void) > > int i; > > int phy_package_id; > > struct rapl_package *new_package, *rp; > > + int lead_cpu; > > > > for_each_online_cpu(i) { > > phy_package_id = topology_physical_package_id(i); > > @@ -1392,7 +1388,11 @@ static int rapl_detect_topology(void) > > /* add the new package to the list */ > > new_package->id = phy_package_id; > > new_package->nr_cpus = 1; > > - > > + /* find the first active cpu of the package */ > > + lead_cpu = cpumask_any_and(topology_core_cpumask(i), > > + cpumask_of(i)); > > Yuck. Why any_and? The result is i, simply because i is online otherwise you > would not be there. > > > + if (lead_cpu < nr_cpu_ids) > > + new_package->lead_cpu = lead_cpu; > > So the above is identical to > > new_package->lead_cpu = lead_cpu;
new_package->lead_cpu = i;
Copy and paste sucks :)
> Hmm? > > > @@ -1500,6 +1503,15 @@ static int rapl_cpu_callback(struct notifier_block *nfb, > > break; > > if (--rp->nr_cpus == 0) > > rapl_remove_package(rp); > > + else if (cpu == rp->lead_cpu) { > > + /* choose another active cpu in the package */ > > + lead_cpu = cpumask_any_but(topology_core_cpumask(cpu), cpu); > > This part is correct. > > Thanks, > > tglx >
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