Re: benchmarking i/o throughput

> > gentryx@wintermute ~ $  ./writeTest 1024 1000 >/tmp/foo
> > status: 0 blksize: 131072
> > sleeping 1000 seconds
> > dumping 1024 mega bytes
> > write took 387639 milli seconds
> > 2.70503 MB/s

Update: I can get even better rates for files < 1024 MB. Those files
don't need to be written in place as there's enough buffer mem on my
system. This allows rates of 3.4 MB/s. 

When writing into a pipe even higher rates are feasible. Per page my
block device performs 3 accesses to the userspace memory: two times a
deputy_get_userX() for different regions (I assume to preload the
cachelines), followed by one deputy_get_user() for the actual
page. The pipe leaves out one of the deputy_get_userX() calls which
leads to a higher througput: 4.5135 MB/s.

-Andreas


-------------------------------------------------------
This SF.Net email is sponsored by xPML, a groundbreaking scripting language
that extends applications into web and mobile media. Attend the live webcast
and join the prime developer group breaking into this new coding territory!
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642