On 10/8/20 8:45 AM, Oleg Nesterov wrote: > On 10/08, Jens Axboe wrote: >> >> On 10/8/20 8:21 AM, Oleg Nesterov wrote: >>> >>> Can't we avoid this patch and the and simplify the change in >>> exit_to_user_mode_loop() from the next patch? Can't the much more simple >>> patch below work? >>> >>> Then later we can even change arch_do_signal() to accept the additional >>> argument, ti_work, so that it can use ti_work & TIF_NOTIFY_SIGNAL/SIGPENDING >>> instead of test_thread_flag/task_sigpending. >> >> Yeah I guess that would be a bit simpler, maybe I'm too focused on >> decoupling the two. But if we go this route, and avoid sighand->lock for >> just having TIF_NOTIFY_SIGNAL set, then that should be functionally >> equivalent as far as I'm concerned. > > Not sure I understand... I think that the change I propose is functionally > equivalent or I missed something. Sorry, maybe my phrasing wasn't good, I'm totally agreeing with you :-) Was just noting that the task_sigpending() is key for not calling get_signal(), to avoid hitting the sighand->lock again. -- Jens Axboe
