> -----Original Message----- > From: Antoine Beaupré [mailto:anarcat@xxxxxxxxxxxxxx] > Sent: Wednesday, May 18, 2022 9:17 PM > To: Vincent Fu <vincent.fu@xxxxxxxxxxx>; fio@xxxxxxxxxxxxxxx > Subject: RE: running jobs serially > > On 2022-05-18 22:41:24, Vincent Fu wrote: > > The jobs you are running have the *stonewall* option which should > make them run > > serially unless something is very broken. > > Yeah, so that's something I added deliberately for that purpose, but two > things make me think it's not working properly. > > 1. the timestamps are identical for the two jobs > > randwrite-4k-4g-1x: (groupid=1, jobs=1): err= 0: pid=1033477: Wed > May 18 15:41:04 2022 > randread-4k-4g-1x: (groupid=0, jobs=1): err= 0: pid=1033470: Wed > May 18 15:41:04 2022 > > 2. when fio starts, it says: > > Starting 2 processes > > i would have expected it to start one process at a time > <snip> > > Speaking of which, it's not clear to me if I need to add stonewall to > each job or if I can just add it to the top-level global options and be > done with it... > The stonewall option is needed only in the global section and will apply to all of the jobs. <snip> > > So maybe the bug is *just* 1 and 2: (1) the timestamps in the final > report are incorrect, and (2) processes are all started at once (and 1 > may be related to 2!) > The timestamp is actually the time at which the summary output was generated, not the time the job started or stopped. https://github.com/axboe/fio/blob/fio-3.30/stat.c#L1161 All of the processes are created when fio starts up but they do not start issuing IO until it is their turn.
