Yes, cpu0 was not offlineable since inception. (both in x86 and x86_64) due to certain other dependencies that would need more cleanup in kernel code. Even though you had an online file earlier, its was a no-op.. basically when you echo 1 to offline to cpu0, we just returned error and did nothing. Cheers, ashok raj - Open Source Technology Center >-----Original Message----- >From: Bryce Harrington [mailto:bryce@xxxxxxxx] >Sent: Monday, May 01, 2006 5:38 PM >To: Raj, Ashok >Cc: Mary Edie Meredith; Hotplug SIG; lhcs-devel@xxxxxxxxxxxxxxxxxxxxx >Subject: Hotplug CPU issue? > >On Tue, Apr 11, 2006 at 10:47:16AM -0700, Raj, Ashok wrote: >> >> > >> > * Patch to fix the CPU issue we discovered with the lhcs_regression >> > testsuite has been validated to fix the issue. >> > >> >> >> Yes this patch is now included in mainline. > >Hi ashok, > >Thanks, I verified this is now working in mainline kernels. However >I've noticed a new issue. > >I've been running my CPU hotplug regression test against recent -rc, >-mm, and -git kernels, on a 2-cpu machine. But I notice that while cpu1 >can be onlined/offlined, cpu0 cannot. This is because there is no >'online' file for cpu0: > > cl009 cpu # ls /sys/devices/system/cpu/cpu* > /sys/devices/system/cpu/cpu0: > topology > > /sys/devices/system/cpu/cpu1: > online topology > >Why would I be seeing the online file only for cpu1? Is x86 incapable >of offlining cpu0? > >Thanks, >Bryce
