Thanks Axboe and Mark. On Mon 29 Oct, 2018, 7:50 PM Beierl, Mark, wrote: > On 2018-10-27, 12:55, "fio-owner@vger.kernel.org on behalf of Jens Axboe" > wrote: > > [EXTERNAL EMAIL] > Please report any suspicious attachments, links, or requests for > sensitive information. > > > On 10/26/18 6:54 AM, Mohanraj B wrote: > > Hello, > > > > I am trying to check how option --clocksource works. > > > > > > bash# fio --name job1 --size 10m --clocksource 2 > > valid values: gettimeofday Use gettimeofday(2) for timing > > : clock_gettime Use clock_gettime(2) for timing > > : cpu Use CPU private clock > > > > fio: failed parsing clocksource=2 > > > > bash# fio --name job1 --size 10m --clocksource gettimeofday(2) > > bash: syntax error near unexpected token `(' > > > > Below command works fine. > > bash# fio --name job1 --size 10m --clocksource gettimeofday > > > > It runs without error but quiet not sure how to see the effect of > this > > option. also tried other options - clock_gettime, cpu gettimeofday > and > > dont see any difference. > > > > Also is there any error in documentation passing gettimeofday(2) > > throws parse error. > > The format is 'value' 'help', so you'd want to do: > > --clocksource=gettimeofday > > for instance. > > -- > Jens Axboe > > Hello, Mohanraj > > The help output that you see above states that using > --clocksource=gettimeofday will use the gettimeofday function as defined in > the man page in the section (2), which is where all the system calls > manuals are stored. The (2) is not meant to be part of the command line, > it is part of the description of the help text, which tells you where to > find more information on what is being used to implement the clocksource. > > Hope that helps clarify the help text. > > Regards, > Mark > > > >