On Mon, Jan 06, 2025 at 12:53:36PM +0000, Charalampos Mitrodimas wrote: > > I did a bit of printk output and it seems like this _didn't_ online CPU 0, > > presumably the boot CPU which calls this function in the first instance? > > FWIW with the proposed fix I can see that all CPUs are online, > grep -H . /sys/devices/system/cpu/cpu*/online > /sys/devices/system/cpu/cpu0/online:1 > /sys/devices/system/cpu/cpu1/online:1 > /sys/devices/system/cpu/cpu2/online:1 > /sys/devices/system/cpu/cpu3/online:1 > /sys/devices/system/cpu/cpu4/online:1 > /sys/devices/system/cpu/cpu5/online:1 > /sys/devices/system/cpu/cpu6/online:1 > /sys/devices/system/cpu/cpu7/online:1 > Sorry maybe I phrased this badly, I'm not suggesting CPUs aren't coming online, I'm saying it doesn't look like vmstat_cpu_online() will be called for the boot CPU, which breaks the proposed fix (the delayed work for this CPU will simply never be enabled in this case). Naturally, the boot CPU is _already_ online at this point, which is I imagine why this is the case. I had wondered if the function would be invoked on the boot CPU _anyway_ but it appears not.
