Re: bug in logging code?

[Mark Nelson <mark.a.nelson@gmail.com>]

On 04/02/2014 12:38 PM, Jens Axboe wrote:
> On 04/02/2014 09:23 AM, Mark Nelson wrote:
>> I've been playing around with usng the various write_*_log options in
>> fio to record run statistics.  What I'm finding is that some of the logs
>> have malformed lines in them.  The following snippet is from the bw log:
>>
>> 811820, 12263, 0, 4194304
>> 812619, 35929, 0, 4194304
>> 818437, 8448, 0, 419430, 4194304
>> 1256299, 160627, 0, 4194304
>> 1256831, 154274, 0, 4194304
>>
>> Notice that the malformed line appears to be a partial write that gets
>> truncated.  The fio command being used to run the tests is
>> autogenerated, so job files aren't used.  here's the one that created
>> the above log snippet:
>>
>> /home/nhm/bin/fio
>> --rw=read
>> --ioengine=libaio
>> --runtime=7200
>> --ramp_time=0
>> --numjobs=1
>> --direct=1
>> --bs=4194304B
>> --iodepth=16
>> --size=9216M
>> --write_iops_log=/tmp/cbt/ceph/kvmrbdfio/osd_ra-00004096/client_ra-00000128/op_size-04194304/concurrent_procs-008/iodepth-016/read/output
>>
>>
>> --write_bw_log=/tmp/cbt/ceph/kvmrbdfio/osd_ra-00004096/client_ra-00000128/op_size-04194304/concurrent_procs-008/iodepth-016/read/output
>>
>>
>> --write_lat_log=/tmp/cbt/ceph/kvmrbdfio/osd_ra-00004096/client_ra-00000128/op_size-04194304/concurrent_procs-008/iodepth-016/read/output
>>
>>
>> --time_based
>> --name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-0
>> --name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-1
>> --name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-2
>> --name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-3
>> --name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-4
>> --name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-5
>> --name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-6
>> --name=/srv/rbdfio-`hostname -s`-0/cbt-kvmrbdfio-7
>>
>> The --numjobs=1 line should be removed, but I believe it gets overridden
>> anyway with multiple name parameters.  I wonder if having multiple name
>> parameters (ie multiple fio processes) is causing those processes to all
>> try to write to the same log files, potentially at the same time?  Any
>> thoughts would be much appreicated!
>
> What version of fio are you running?
>

f42557f (ie master from yesterday) with a slightly different fix for the 
basename issues that just got resolved.

I can verify now that running fio with a single --name flag appears to 
generate logs without malformated lines.

Mark