This is a note to let you know that I've just added the patch titled MIPS: CPU#0 is not hotpluggable to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mips-cpu-0-is-not-hotpluggable.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 9cce844abf07b683cff5f0273977d5f8d0af94c7 Mon Sep 17 00:00:00 2001 From: Huacai Chen <chenhc@xxxxxxxxxx> Date: Thu, 16 Jul 2020 18:40:23 +0800 Subject: MIPS: CPU#0 is not hotpluggable From: Huacai Chen <chenhc@xxxxxxxxxx> commit 9cce844abf07b683cff5f0273977d5f8d0af94c7 upstream. Now CPU#0 is not hotpluggable on MIPS, so prevent to create /sys/devices /system/cpu/cpu0/online which confuses some user-space tools. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx> Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/mips/kernel/topology.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/mips/kernel/topology.c +++ b/arch/mips/kernel/topology.c @@ -20,7 +20,7 @@ static int __init topology_init(void) for_each_present_cpu(i) { struct cpu *c = &per_cpu(cpu_devices, i); - c->hotpluggable = 1; + c->hotpluggable = !!i; ret = register_cpu(c, i); if (ret) printk(KERN_WARNING "topology_init: register_cpu %d " Patches currently in stable-queue which might be from chenhc@xxxxxxxxxx are queue-5.4/mips-cpu-0-is-not-hotpluggable.patch