On 08/07/2013 04:36 AM, Dennis Jacobfeuerborn wrote: > On 07.08.2013 11:10, Erwan Velu wrote: >> On 07/08/2013 00:08, Dennis Jacobfeuerborn wrote: >>> Hi, >>> when I try to create logs with fio I get bw, iops, lat, clat and slat >>> logs but the slat log always has a size of 0 bytes. Is this a bug or >>> is data for this log only generated with specific options for fio? >>> >> Dennis, >> >> I've been trying this on my 2.1.2 with the following job : >> >> [read-sda-4k-para] >> bs=4k >> filename=/dev/sda >> rw=read >> write_lat_log=lat.log >> >> On my side, the slat file is perfectly filled. >> >> Can you provide a testing procedure & the version you use ? > > I just tested the job above and these are the files produced: > > [dennis@nexus fio]$ ls -l > total 11272 > -rw-r--r--. 1 root root 5767080 7. Aug 12:31 lat.log_clat.log > -rw-r--r--. 1 root root 5767087 7. Aug 12:31 lat.log_lat.log > -rw-r--r--. 1 root root 0 7. Aug 12:31 lat.log_slat.log > -rw-rw-r--. 1 dennis dennis 84 7. Aug 12:31 logtest.fio > > There are not errors or warnings during the fio run so it's not clear > why the file ends up being empty. slat only exists for async IO engines. For a sync workload, submission and completion retrieval are not separate events, so you cannot do split submission + completion stats. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
