Hello, Nikolay. On Tue, Jun 20, 2017 at 09:02:00PM +0300, Nikolay Borisov wrote: > Currently the writeback statistics code uses a percpu counters to hold > various statistics. Furthermore we have 2 families of functions - those which > disable local irq and those which doesn't and whose names begin with > double underscore. However, they both end up calling __add_wb_stats which in > turn calls percpu_counter_add_batch which is already irq-safe.
Heh, looks like I was confused. __percpu_counter_add() is not irq-safe. It disables preemption and uses __this_cpu_read(), so there's no protection against irq. If writeback statistics want irq-safe operations and it does, it would need these separate operations. Am I missing something? Thanks. -- tejun
