/sys/devices/system/cpu/cpu*/online don't exist anymore. When the kernel is booted with maxcpus=1 /sys/devices/system/cpu/cpu1 is also missing:
$ ls -la /sys/devices/system/cpu/ totale 0 drwxr-xr-x 3 root root 0 9 feb 23:15 . drwxr-xr-x 7 root root 0 9 feb 23:15 .. drwxr-xr-x 4 root root 0 9 feb 23:15 cpu0 -r--r--r-- 1 root root 4096 9 feb 23:15 online -r--r--r-- 1 root root 4096 9 feb 23:15 possible -r--r--r-- 1 root root 4096 9 feb 23:15 present $ cat /sys/devices/system/cpu/online 0 $ cat /sys/devices/system/cpu/possible 0-1 $ cat /sys/devices/system/cpu/present 0-1 $ uname -a Linux Jay 2.6.28 #1 SMP Sun Jan 11 22:42:31 CET 2009 ppc 7455, altivec supported PowerMac3,6 GNU/Linux Looking at the 2.6.28 diff, i noticed there is a patch to setup_32.c::ppc_init() that removes the following: for_each_possible_cpu(cpu) { struct cpu *c = &per_cpu(cpu_devices, cpu); c->hotpluggable = 1; register_cpu(c, cpu); } Reverting it makes the kernel hang at boot. The only other place where ->hotpluggable is set is in sysfs.c::topology_init(), but it only happens if ppc_md.cpu_die!=NULL and I couldn't find where that pointer is set. Any clue ? TIA, -- Giuliano. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev