Chapter 13. Kernel

Processes reading the /proc/stat file cause high CPU usage

CPU usage is high on the system when many processes are reading the /proc/stat file. This is caused by contention on the sparse_irq_lock kernel lock.
To work around this problem, add the kstat_irq_nolock argument on the kernel command line. This disables the lock and lowers CPU usage, but it might lead to the system becoming unresponsive in extremely rare cases due to a race condition. (BZ#1544565)