[Sitsofe Wheeler - Mon, May 26, 2008 at 08:36:54PM +0100] | <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/ | | Thanks a lot! Will take a look tomorrow! And there was NOT an infinite loop - look more closer on that string do { } while (0) - only *one* iteration is going (well, gcc will eliminate it at all by optimization). Anyway, it was while (0), not while (1), so it is ok ;) - Cyrill - -- 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
