svn commit: r239598 - head/etc/rc.d

David O'Brien obrien at FreeBSD.org
Wed Sep 5 20:40:51 UTC 2012


On Tue, Sep 04, 2012 at 02:15:17PM -0600, Ian Lepore wrote:
>  pscmd="ps -fauxrH -o nwchan,nivcsw,nvcsw,time,re,sl"

I do like the changes that this gives over 'ps -fauxww'.

root  11 80.6  0.0 0 32 - RL 8:40AM 0:03.09 [idle]     -                1078 1495 0:03.09 8 8
root  11 42.8  0.0 0 32 - RL 8:40AM 0:04.23 [idle]     -                1401 1012 0:04.23 8 8
root   5 21.6  0.0 0 16 - DL 8:40AM 0:02.17 [xpt_thrd] ffffffff811931e0  104    1 0:02.17 8 4

-vs-
root  11 121.9 0.0 0 32 - RL 8:40AM 0:06.48 [idle]
root   5  21.6 0.0 0 16 - DL 8:40AM 0:00.00 [xpt_thrd]


> The sysctl -a in the original initrandom sequence was part of the killer
> for execution time.  On a 180mhz arm chip that command alone takes like
> 3 seconds, and it generates a lot of unchanging boilerplate text.  I
> remember picking a few select values that had a good chance of being
> different from one run to the next.  

I've found that 'sysctl -a' can generate ~270K of output with very little
of it differing between runs.  I've checked the output across reboots at
the point that 'initrandom' runs.

I've found
	sysctl kern.cp_times kern.cp_time kern.geom kern.lastpid \
	kern.timecounter kern.tty_nout kern.tty_nin vm vfs debug dev.cpu
to concentrate the changes across reboots.  However, I have not tested
this on ARM or MIPS to ensure these MIB's exist.

Just to double check, you're saying the 3 seconds was for
'sysctl -a > /dev/null' vs. feeding that amount of input into
/dev/random?


> Those commands still generated a fair amount of unchanging boilerplate
> text, and it's mostly the numbers that change, so I fed all the output
> through tr to strip out everything but the numbers.

I would use "tr -Cd '0123456789xabcdef'" since many of the numbers are
in hex, and would restrict to just the sysctl output.  But otherwise I
like this idea.

Can you time some things on your ARM?  'sysctl -a' vs. my MIB list above?
Also your shorter list?

-- 
-- David  (obrien at FreeBSD.org)


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