* Arne Jansen <lists@xxxxxxxxxxxxxx> wrote: > >( Arne, please also double check on a working bootup that the NMI > > watchdog is actually ticking, by checking the NMI counts in > > /proc/interrupts go up slowly but surely on all CPUs. ) > > It does, but _very_ slowly. Some CPUs do not count up for tens of > minutes if the machine is idle. If I generate some load like 'make > tags', the counters go up quite quickly. > After 4 minutes and one 'make cscope' it looks like this: > NMI: 8 13 43 5 2 > 3 22 1 Non-maskable interrupts > > But I never see a single tick on console or in dmesg, even when I > replace the early_printk with a printk. hm, that might be because the NMI watchdog uses halted cycles to tick. That's not a problem (the kernel cannot lock up while there are no cycles ticking) but nevertheless could you work this around please by starting 8 infinite shell loops: for ((i=0; i<8; i++)); do while : ; do : ; done & done ? This will saturate all cores and makes sure the NMI watchdog is ticking everywhere. Hopefully this wont make the bug go away :-) This will remove one factor of uncertainty (of where the NMI watchdog is working or not), so it simplifies debugging. > [ 36.064321] ------------[ cut here ]------------ > [ 36.064328] WARNING: at kernel/printk.c:293 do_syslog+0xbf/0x550() > [ 36.064330] Hardware name: X8SIL > [ 36.064331] Attempt to access syslog with CAP_SYS_ADMIN but no > CAP_SYSLOG (deprecated). Yeah, unrelated, and rather annoying looking that warning. The warning is borderline correct (it's messy to drop CAP_SYSLOG but keep CAP_SYS_ADMIN) but still, if we warned every time userspace relies on something the kernel provided in the past, in a somewhat messy way, we'd never complete bootup i guess ;-) Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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