• Steven Rostedt's avatar
    Thermal: Fix lockup of cpu_down() · ace120dc
    Steven Rostedt authored
    Commit f1a18a10 "Thermal: CPU Package temperature thermal" had code
    that did a get_online_cpus(), run a loop and then do a
    put_online_cpus(). The problem is that the loop had an error exit that
    would skip the put_online_cpus() part.
    
    In the error exit part of the function, it also did a get_online_cpus(),
    run a loop and then put_online_cpus(). The only way to get to the error
    exit part is with get_online_cpus() already performed. If this error
    condition is hit, the system will be prevented from taking CPUs offline.
    The process taking the CPU offline will lock up hard.
    
    Removing the get_online_cpus() removes the lockup as the hotplug CPU
    refcount is back to zero.
    
    This was bisected with ktest.
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
    ace120dc
x86_pkg_temp_thermal.c 16.2 KB