Messages in this thread | | | Date | Fri, 18 Jun 2010 11:48:38 +0200 | From | Ingo Molnar <> | Subject | Re: [RFC 1/3] Unified NMI delayed call mechanism |
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* Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> wrote:
> (2010/06/12 19:25), Ingo Molnar wrote: > > > > * Huang Ying <ying.huang@intel.com> wrote: > > > >> NMI can be triggered even when IRQ is masked. So it is not safe for NMI > >> handler to call some functions. One solution is to delay the call via self > >> interrupt, so that the delayed call can be done once the interrupt is > >> enabled again. This has been implemented in MCE and perf event. This patch > >> provides a unified version and make it easier for other NMI semantic handler > >> to take use of the delayed call. > > > > Instead of introducing this extra intermediate facility please use the same > > approach the unified NMI watchdog is using (see latest -tip): a perf event > > callback gives all the extra functionality needed. > > > > The MCE code needs to be updated to use that - and then it will be integrated > > into the events framework. > > Hi Ingo, > > I think this "NMI delayed call mechanism" could be a part of "the events > framework" that we are planning to get in kernel soon. [...]
My request was to make it part of perf events - which is a generic event logging framework. We dont really need/want a second 'events framework' as we have one already ;-)
> [...] At least APEI will use NMI to report some hardware events (likely > error) to kernel. So I suppose we will go to have a delayed call as an > event handler for APEI.
Yep, that makes sense. I wasnt arguing against the functionality itself, i was arguing against the illogical layering that limits its utility. By making it part of perf events it becomes a generic part of that framework and can be used by anything that deals with events and uses that framework.
Thanks,
Ingo
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