Hi Bart On 05/14/2018 12:03 PM, Bart Van Assche wrote: > On Mon, 2018-05-14 at 09:37 +0800, jianchao.wang wrote: >> In addition, on a 64bit system, how do you set up the timer with a 32bit deadline ? > > If timeout handling occurs less than (1 << 31) / HZ seconds after a request has been > submitted then a 32-bit variable is sufficient to store the deadline. If you want to > verify the implementation, please have a look at the int32_t variables in > blk_mq_check_expired(). > a 32bit deadline is indeed OK to judge whether a request is timeout or not. but how is the expires value determined for __blk_add_timer -> mod_timer ? as we know, when a request is started, we need to arm a timer for it. the expires value is 'unsigned long'. Thanks Jianchao
