On Thu, Feb 4, 2021 at 9:46 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > On Thu, Feb 04, 2021 at 01:01:57AM +0000, Alexey Klimov wrote: > > @@ -1281,6 +1282,11 @@ static int cpu_up(unsigned int cpu, enum cpuhp_state target) > > err = _cpu_up(cpu, 0, target); > > out: > > cpu_maps_update_done(); > > + > > + /* To avoid out of line uevent */ > > + if (!err) > > + cpuset_wait_for_hotplug(); > > + > > return err; > > } > > > > > @@ -2071,14 +2075,18 @@ static void cpuhp_online_cpu_device(unsigned int cpu) > > struct device *dev = get_cpu_device(cpu); > > > > dev->offline = false; > > - /* Tell user space about the state change */ > > - kobject_uevent(&dev->kobj, KOBJ_ONLINE); > > } > > > > One concequence of this is that you'll now get a bunch of notifications > across things like suspend/hybernate. The patch doesn't change the number of kobject_uevent()s. The userspace will get the same number of uevents as before the patch (at least if I can rely on my eyes). Or is there a concern that now the uevents are sent in a row sequentially which might abuse userspace uevents handling machinery? Best regards, Alexey
