Re: Latency log, add filename to record

[Jens Axboe <axboe@kernel.dk>]

On Sat, Nov 16 2013, Jens Axboe wrote:
> On Thu, Nov 07 2013, chris meyers wrote:
> > https://github.com/axboe/fio/pull/3
> > The above patch modifies the CSV latency log (write_lat_log options)
> > by appending the filename to which the record is related. Said
> > differently, the filename to which the I/O was issued to. When I first
> > set out to add this feature I had indended to create a new log file in
> > order to distrubt the latency log file format as little as possible.
> > This, however, was not easily doable given the structure of the fio
> > code. Now, in order to still provide this feature while maintaining
> > the legacy latency file format I propose two options.
> > (1) A configuration options as an extention to write_lat_log. For example:
> > write_lat_log=mylogfile:with_filename
> > (2) As a seperate configuration option that modifies the write_lat_log
> > format. For example:
> > write_lat_log_with_filename=bool
> > 
> > This email is to start a discussion and solicit feedback on the
> > proposed feature as well as the cooresponding configuration trigger.
> 
> Chris, sorry for being late on this! I'll get to this on Monday and give
> you some constructive criticism.

OK, finally got to it. One problem with adding to the log structure is
that it grows in size. And we already have a problem with it eating too
much memory. But I actually have a few ideas on how to 'compress' it, so
lets not worry too much about that.

Lets add a new option to include the name. write_lat_log_with_filename
sounds like a reasonable choice.

-- 
Jens Axboe