Quoting Thomas Gleixner (2019-09-07 16:00:17)
> Does this only happen with that CPU0 hotplug stuff enabled or on CPUs other
> than CPU0 as well? That hotplug CPU0 stuff is a bandaid so I wouldn't be
> surprised if we broke that somehow.
If I ignore cpu0 in that test and so use
[ 133.847187] smpboot: CPU 1 is now offline
[ 134.861861] x86: Booting SMP configuration:
[ 134.861875] smpboot: Booting Node 0 Processor 1 APIC 0x2
[ 134.880218] smpboot: CPU 2 is now offline
[ 135.893806] smpboot: Booting Node 0 Processor 2 APIC 0x1
[ 135.935115] smpboot: CPU 3 is now offline
[ 136.949760] smpboot: Booting Node 0 Processor 3 APIC 0x3
that has run for 10 minutes without failure, so it seems confined to
cpu0 hotplugging. All we are doing in the test to generate the hotplugs
is:
for (int cpu = 0;; cpu++) {
char name[128];
int cpufd;
snprintf(name, sizeof(name),
"/sys/devices/system/cpu/cpu%d/online",
cpu), sizeof(name));
cpufd = open(name, O_WRONLY);
if (cpufd < 0)
break;
write(cpufd, "0", 2);
usleep(1e6);
write(cpufd, "1", 2);
close(cpufd);
}
-Chris
