Re: More Slowdown - testscript [noatime,nodiratime]

[Hans Reiser <reiser@namesys.com>]

Craig Shelley wrote:

>With the noatime and nodiratime options, the problem of accessing files
>causing a massive sync time has gone. See the results below.
>
>Although this option has made the system useable, I don't think it has
>fully solved the problem. I think fsync() and sync() performance is
>still poor, I will do a bit more testing and get back.
>
>Regards,
>
>  
>
Sounds like we need to specifically optimize fsync.  Well, we have known
that for a while, but now it is more true.

Ways we can do it include using write twice journaling to a fixed
journal area for fsync, and making it possible to specify for a
particular file that it should have an atime, and then letting noatime
be the default.

Probably doing both is best.

Atime has been hated by most fs designers for a very very long time, so
there might be less resistance to a new standard for this than one would
think.

Hans