> On Jan 22, 2025, at 20:50, Petr Mladek <pmladek@xxxxxxxx> wrote: > > With this patch, any operation which takes the tasklist_lock might > break klp_try_complete_transition(). I am afraid that this might > block the transition for a long time on huge systems with some > specific loads. > > And the problem is caused by a printk() added just for debugging. > I wonder if you even use a slow serial port. > > You might try to use printk_deferred() instead. Also you might need > to disable interrupts around the read_lock()/read_unlock() to > make sure that the console handling will be deferred after > the tasklist_lock gets released. > > Anyway, I am against this patch. > > Best Regards, > Petr Hi, Petr. I am unfamiliar with the function `rwlock_is_contended`, but it seems this function will not block and just only check the status of the rw_lock. If I understand it right, the problem would raise from the `break` which will stop the process of `for_each_process_thread`, right? Thanks. Wardenjohn.
