Re: nmi_watchdog suspicious

Cyrill Gorcunov
2008-06-18T17:23:48Z

[Maciej W. Rozycki - Wed, Jun 18, 2008 at 05:54:32PM +0100]
| On Wed, 18 Jun 2008, Cyrill Gorcunov wrote:
|
| > Maciej, it seems we are talking about different code snippets ;)
| > I'm talking only about touch_nmi_watchdog(). By now (in -tip tree
| > we have)
| >
| > void touch_nmi_watchdog(void)
| > {
| > if (nmi_watchdog == NMI_LOCAL_APIC ||
| > nmi_watchdog == NMI_IO_APIC) {
| > unsigned cpu;
| > ...
| >
| > so we check explicitly the values (so if touch_nmi_watchdog
| > was called when nmi_watchdog = 0 or -1U this code will not
| > be executed anyway). So I think I'm a bit lost, Maciej... I just
| > can't figure out what is wrong with this code, so please help
| > me ;). If you're talking about apic code in _general_ design
| > then...well, I think I need some time to _understand_ the code
| > say byte-by-byte first.
|
| The value of nmi_watchdog being NMI_IO_APIC or NMI_LOCAL_APIC does not
| mean the watchdog has been set up already. This observation applies both
| here and elsewhere, e.g. to nmi_watchdog_tick().
|
| Maciej
|

If you mean the case we get NMI physical line assetred while configuring APIC
(ie nmi watchdog is not properly configured yet) then I wonder why we has
this checking at all...

- Cyrill -