Marco Crivellari <marco.crivellari@suse.com> says: Currently the code uses the per-cpu workqueue system_long_wq to schedule long running works. Unbound works could benefit from scheduler task placement, to optimize performance and power consumption. Another good reason to have this unbound, is the "queue_delayed_work()" function, used to enqueue the work item. More details on this will follow in the next section. Recently, a new unbound workqueue specific for long running work has been added: c116737e972e ("workqueue: Add system_dfl_long_wq for long unbound works") ~~~ Details about queue_delayed_work ~~~ system_long_wq is a per-cpu workqueue and it is used as a parameter of queue_delayed_work(). This function schedule an item that it will later be enqueued (once the timer will fire). __queue_delayed_work() does the job receiving as "cpu" WORK_CPU_UNBOUND: if (housekeeping_enabled(HK_TYPE_TIMER)) { // [....] } else { if (likely(cpu == WORK_CPU_UNBOUND)) add_timer_global(timer); else add_timer_on(timer, cpu); } The timer is global, so can fire everywhere, and the work item will be enqueued where the timer fired. Since the workqueue work doesn't rely on per-cpu variables, there is no obvious reason that justify the use of a per-cpu workqueue. So change the workqueue with the new system_dfl_long_wq, so that the used workqueue is now unbound and can benefit from scheduler task placement.