On Mon, Jan 25, 2021 at 10:54:12AM +0100, Sebastian Andrzej Siewior wrote: > With llist_head it is possible to avoid the locking (the irq-off region) > when items are added. This makes it possible to add items on a remote > CPU without additional locking. > llist_add() returns true if the list was previously empty. This can be > used to invoke the SMP function call / raise sofirq only if the first > item was added (otherwise it is already pending). > This simplifies the code a little and reduces the IRQ-off regions. > > blk_mq_raise_softirq() needs a preempt-disable section to ensure the > request is enqueued on the same CPU as the softirq is raised. > Some callers (USB-storage) invoke this path in preemptible context. > > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> I did a quick test run with the whole series. Looks good. Reviewed-by: Daniel Wagner <dwagner@xxxxxxx>
