On Wed, Nov 07, 2007 at 03:35:43AM +0100, Andi Kleen wrote: > On Wednesday 07 November 2007 02:12, Andreas Herrmann wrote: > > > In cases where not all CPUs are brought up during > > boot (e.g. using maxcpus and additional_cpus parameters) > > mce_cpu_callback now returns NOTFIY_BAD because > > for such CPUs cpu_data is not completely filled when > > the notifier is called. Thus mce_create_device fails right > > at its beginning: > > > > if (!mce_available(&cpu_data[cpu])) > > return -EIO; > > > > As a quick fix I suggest to check boot_cpu_data for MCE. > > I guess it would be better to just move the device creation > to after the CPU has booted. AKA call mce_create_dev() on CPU_ONLINE > instead.
Yes, and this was the old behaviour. The mentioned patch changed it - ("do mce_create_device in CPU_UP_PREPARE instead of CPU_ONLINE"). Thinking twice about the problem it seems obvious that this part of the patch should just be reverted. Attached is a new fix (diff against 2.6.24-rc2). Regards, Andreas -- [PATCH] x86: fix cpu hotplug regression (don't call mce_create_device on CPU_UP_PREPARE) Fix regression introduced with d435d862baca3e25e5eec236762a43251b1e7ffc ("cpu hotplug: mce: fix cpu hotplug error handling"). For CPUs not brought up during boot (using maxcpus and additional_cpus parameters) we don't know whether mce is supported or not at "CPU_UP_PREPARE"-time. Thus mce_cpu_callback should be called after the CPU is online. Signed-off-by: Andreas Herrmann <[EMAIL PROTECTED]> --- arch/x86/kernel/cpu/mcheck/mce_64.c | 6 ++---- 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce_64.c b/arch/x86/kernel/cpu/mcheck/mce_64.c index b9f802e..8e83070 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_64.c +++ b/arch/x86/kernel/cpu/mcheck/mce_64.c @@ -855,12 +855,10 @@ mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) int err = 0; switch (action) { - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: err = mce_create_device(cpu); break; - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: case CPU_DEAD: case CPU_DEAD_FROZEN: mce_remove_device(cpu); -- 1.5.3.4 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/