On 5/26/08, Sitsofe Wheeler <sitsofe@xxxxxxxxx> wrote: > <posted & mailed> > > Sitsofe Wheeler wrote: > > > Cyrill Gorcunov wrote: > > > >> [Sitsofe Wheeler - Mon, May 26, 2008 at 03:04:54PM +0100] > >> | When using a 32 bit linux-next-20080526 the bootup process will hang at > >> | a random point (not even sysrq helps) with no additional output on the > >> | screen (whereas linux-next-20080523 did boot). Mysteriously, booting > >> | with nmi_watchdog=2 allows the boot to finish (booting with > >> | nmi_watchdog=1 still stalls). I have bisected it down to commit > >> | [d1b946b97d71423f365fa797d1428e1847c0bec1]: > >> > >> Hi, so it helps by reverting only that commit? I mean all further commits > >> are still appiled? > > > > Ah that I hadn't tested. I believe I might need to revert > > 4b82b277707a39b97271439c475f186f63ec4692 too if later commits are applied > > (but I'm still testing) > > > >> and, btw, could you post your config, please? > > > > http://sucs.org/~sits/test/config-20080526.txt > > OK applying the following patch (which is more or less a revert of > [4b82b277707a39b97271439c475f186f63ec4692]) resolves the problem: > > diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c > index d99ee8a..c55519c 100644 > --- a/arch/x86/kernel/nmi.c > +++ b/arch/x86/kernel/nmi.c > @@ -480,8 +480,12 @@ int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file, > return -EIO; > } > > - /* if nmi_watchdog is not set yet, then set it */ > - nmi_watchdog_default(); > + if (nmi_watchdog == NMI_DEFAULT) { > + if (lapic_watchdog_ok()) > + nmi_watchdog = NMI_LOCAL_APIC; > + else > + nmi_watchdog = NMI_IO_APIC; > + } > > if (nmi_watchdog == NMI_LOCAL_APIC) { > if (nmi_watchdog_enabled) > diff --git a/include/asm-x86/nmi.h b/include/asm-x86/nmi.h > index 1e8f34d..7cd5b6a 100644 > --- a/include/asm-x86/nmi.h > +++ b/include/asm-x86/nmi.h > @@ -38,9 +38,11 @@ static inline void unset_nmi_pm_callback(struct pm_dev *dev) > > #ifdef CONFIG_X86_64 > extern void default_do_nmi(struct pt_regs *); > +extern void nmi_watchdog_default(void); > +#else > +#define nmi_watchdog_default() do {} while (0) > #endif > > -extern void nmi_watchdog_default(void); > extern void die_nmi(char *str, struct pt_regs *regs, int do_panic); > extern int check_nmi_watchdog(void); > extern int nmi_watchdog_enabled; > > The removal of extern void nmi_watchdog_default(void) and the inclusion > of #define nmi_watchdog_default() do {} while (0) look suspicious (why > would nmi_watchdog_default() need to be an infinite loop on 32 bit > systems?). > > -- > Sitsofe | http://sucs.org/~sits/ > Hi Sitsofe, actually I can't imagine how this revert have helped you from hang. Newly introduced nmi_watchdog_default() didn't change the logic of the code being used before this merge-series. Thomas, Ingo, maybe I've overlooked something (hard to believe ;)? Only the change is the adding of new call for nmi_watchdog_default() which was say 'inlined' before. The thread is started on http://lkml.org/lkml/2008/5/26/146 -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
