Re: [RFC -tip] perf, x86: Add PERF_COUNT_HW_NMI_WATCHDOG event v2

[Cyrill Gorcunov <gorcunov@gmail.com>]

On Thu, Jun 23, 2011 at 07:40:55AM -0400, Don Zickus wrote:
> On Thu, Jun 23, 2011 at 03:07:06PM +0400, Cyrill Gorcunov wrote:
> > On Thu, Jun 23, 2011 at 01:54:39PM +0400, Cyrill Gorcunov wrote:
> > ...
> > > > 
> > > > No new hidden event, just a x86_pmu + a per-arch callbacks.
> > > 
> > > Looks quite good for me, Don? (i'll cook some draft patch for review meanwhile).
> > > 
> > > 	Cyrill
> > 
> > Since we are going to make __weak linking anyway maybe something like below
> > fit even beter? (untested)
> 
> I don't think the compiler knows what platform you are running on and may
> just blindly link your new p4 function for all x86s, which is probably not
> what you want.

As only there will be second/third and so on implementation of hw_nmi_watchdog_set_attr
then indeed it become a problem, for a while it's not, only single
implementation. I personally don't like much __weak linking until there is
no other choise, so explicit general event for x86 in a sake of nmi-watchdog
(without any __weak functions) is my favorite but I'm fine with Stephane proposal
as well, so Don what is your choise?

	Cyrill