Re: ps performance sucks (was Re: dcache_rcu [performance results])

[Martin J. Bligh]

> Hehe.  You just reinvented my old /dev/ps driver.  :)

Indeed, sounds much more like a /dev thing than a /proc thing
at this point ;-)

> http://www.busybox.net/cgi-bin/cvsweb/busybox/examples/kernel-patches/devps.patch.9_25_2000?rev=1.2&content-type=text/vnd.viewcvs-markup
> 
> This is what Linus has to say on the subject:
> 
> ... If the problem is that /proc
>     is too large, then the right solution is to just clean up
>     /proc.  Which is getting done.  And yes, /proc will be larger
>     than /dev/ps, but I still find that preferable to having two
>     incompatible ways to do the same thing.

Ummm ... how do we make /proc smaller than 1 file to open per PID?
It's pretty easy to get it down that far. But it still sucks.

>     I do dislike /dev/ps mightily.

Well it can't be any worse than the current crap. At least it'd 
stand a chance in hell of scaling a little bit. So I took a very 
quick look ... what syscalls are you reduced to per pid, one ioctl 
and one read?

M.