it passes my simple test, I'll try it out in the large next, thx Jens. This is the last commit I saw in master branch upstream just now after pulling into my clone: commit e35fb4c43ecc5b9d35cb5d980e811d3408fc5a4e Author: Jens Axboe <axboe@xxxxxx> Date: Fri May 27 11:01:15 2016 -0600 server: ensure that we flush compressed logs correctly Do chunkwise block compression, and flush at the end, adding more space as needed. Signed-off-by: Jens Axboe <axboe@xxxxxx> When I run fio -h after rebuild, it shows I'm on this commit because last 4 hex digits of version "fio-2.11-5-ge35f" are first 4 digits of git commit ID, which is reassuring. ----- Original Message ----- > From: "Jens Axboe" <axboe@xxxxxxxxx> > To: "Ben England" <bengland@xxxxxxxxxx>, fio@xxxxxxxxxxxxxxx > Cc: "Tim Wilkinson" <twilkins@xxxxxxxxxx>, "Andrew Theurer" <atheurer@xxxxxxxxxx>, "John Harrigan" > <jharriga@xxxxxxxxxx> > Sent: Friday, May 27, 2016 1:02:10 PM > Subject: Re: problem with fio --client and latency logs > > On 05/27/2016 08:43 AM, Jens Axboe wrote: > > On 05/26/2016 01:11 PM, Ben England wrote: > >> recently I noticed a problem in master branch when fio --client is > >> used. latency logs generated with it have large numbers of "0, 0, 0, > >> 0" records at the end of the file. I have a simple reproducer fio > >> jobfile: > >> > >> --------- reproducer.fiojob ---- > >> [global] > >> numjobs=1 > >> directory=/var/tmp > >> > >> [shared-files] > >> rw=randread > >> write_lat_log=1thr > >> ioengine=sync > >> bs=4k # I/O size > >> filesize=1g # file size > >> runtime=20 > >> ------------- > >> > >> If you run this job file like this: > >> > >> # fio --server --daemonize=/var/run/fiosvr.pid > >> # fio --client=localhost reproducer.fiojob > >> > >> You get the latency log 1thr_clat.1.log with the 0 records at the > >> end. If you run the same job file with: > >> > >> # fio reproducer.fiojob > >> > >> You don't get the 0 records. This explains why Ceph CBT does not have > >> the problem, for example. > >> > >> I bisected fio history using git until I found the first commit that > >> failed: > >> > >> ------- > >> commit 0cba0f919ee6af7dd65df436884336cff9c903f9 > >> Author: Jens Axboe <axboe@xxxxxx> > >> Date: Thu Dec 17 14:54:15 2015 -0700 > >> > >> client/server: transparent handling of storing compressed logs > >> > >> Signed-off-by: Jens Axboe <axboe@xxxxxx> > >> ------ > >> > >> I could use some help figuring out what went wrong at this point, the > >> diffs were complicated but it seemed possible that this commit was > >> related to my problem. > > > > I have a good idea what this might be, I'll take a look at it. > > http://git.kernel.dk/cgit/fio/commit/?id=e35fb4c43ecc5b9d35cb5d980e811d3408fc5a4e > > This should fix it, can you try with current -git? > > -- > 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