Cpu movement when idle

Dear Friends,

On both laptops using Mate, after yesterday's update, the cpu is never truly idle. The only thing I can find by myself is :

/sys/firmware/acpi/interrupts/gpe_all:     442
/sys/firmware/acpi/interrupts/gpe03:     439  EN     enabled      unmasked
/sys/firmware/acpi/interrupts/sci:     442

not catastrophic, like the old kworker issue, but annoying and unexpected. I believe yesterdays update included a firmware pacakage.

Any ideas.