Messages in this thread | | | Date | Fri, 8 Jul 2011 15:09:14 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH -tip, final] perf, x86: Add hw_watchdog_set_attr() in a sake of nmi-watchdog on P4 |
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* Cyrill Gorcunov <gorcunov@gmail.com> wrote:
> On Fri, Jul 08, 2011 at 02:49:06PM +0200, Ingo Molnar wrote: > > > > * Cyrill Gorcunov <gorcunov@gmail.com> wrote: > > > > > > On P4 BUS_CYCLES would be able to co-exist with CPU_CYCLES so it > > > > will solve the P4 issue naturally as well. > > > > > > i don't think it changes much, Ingo, if I change it to bus cycles I > > > still will have to setup nmi-watchdog event separately (but simply > > > with bus event). > > > > You did not understand my point, my suggestion is to change this in > > kernel/watchdog.c: > > > > static struct perf_event_attr wd_hw_attr = { > > .type = PERF_TYPE_HARDWARE, > > .config = PERF_COUNT_HW_CPU_CYCLES, > > > > to: > > > > static struct perf_event_attr wd_hw_attr = { > > .type = PERF_TYPE_HARDWARE, > > .config = PERF_COUNT_HW_BUS_CYCLES, > > > > Thanks, > > > > Ingo > > Ah, I see. Ingo, if events alias patch I posted yesterday will do > the trick we will be able to simply drop all this hooks. So as only > Don (or someone) confirm the patch works I'll kill this mess. > > Changing cpu-cycles to bus cycles will allow nmi-watchdog and perf > top co-exsist but it means perf bus-cycles won't work anymore with > active nmi-watchdog. So I think events aliases (again, if it work > :) will be better for us, right?
Sure, being able to start two cycles events at once is better - assuming that those aliases work fine.
Thanks,
Ingo
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