Re: Using get_cycles for add_timer_randomness

[Richard Mortimer <richm@oldelvet.org.uk>]

On Sun, 2004-08-15 at 23:48, Andrew Morton wrote: 
> Things have changed a bit - sparc now has special-case code in there too. 
> Hopefully we can remove that now.
That came from Dave M & me before Anton remembered Arnd's patch. It can
be removed with the new patch applied.

> Is everyone OK with this?
I certainly am. I have tried the patch on sparc64 (albeit on 2.4.26) and
get similar results to Anton.

Richard

> 
> From: Anton Blanchard <anton@samba.org>
> 
> I tested how long it took to do a dd from /dev/random on ppc64 before and
> after this patch, while doing a ping flood from another machine.
> 
> before:
> # /usr/bin/time dd if=/dev/random of=/dev/zero count=1k
> 0+51 records in
> Command terminated by signal 2
> 0.00user 0.00system 19:18.46elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k
> 
> I gave up after 19 minutes.
> 
> after:
> # /usr/bin/time dd if=/dev/random of=/dev/zero count=1k
> 0+1024 records in
> 0.00user 0.00system 0:33.38elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k
> 
> Just over 33 seconds. Better.
> _

-- 
richm@oldelvet.org.uk