[ECOS] Random question about performance

[ECOS] Random question about performance

[Chuck McManis]

So Redboot isn't a speed demon, I knew that, but pings to redboot take on 
average 4 - 6 milliseconds. Pings to UNIX running on the same hardware take 
.4 - .8 milleseconds. That is not quite 10x slower. I know Redboot is a 
polled networking system but it doesn't have to context switch either. 
What's up with that?

--Chuck

(who is busily desconstructing possible workarounds in his ethernet driver 
now that its working ;-)


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Re: [ECOS] Random question about performance

[Gary Thomas]

On Sun, 2006-02-19 at 20:09 -0800, Chuck McManis wrote:
> So Redboot isn't a speed demon, I knew that, but pings to redboot take on 
> average 4 - 6 milliseconds. Pings to UNIX running on the same hardware take 
> .4 - .8 milleseconds. That is not quite 10x slower. I know Redboot is a 
> polled networking system but it doesn't have to context switch either. 
> What's up with that?

This is probably more about what else it's polling.  RedBoot only
polls the network device, and hence answers pings, as it's waiting
for "console" input.  Depending on the device you have, and the
number of them if you are in "any console" mode, this can take a
while between polls.

-- 
Gary Thomas <gary@mlbassoc.com>


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[ECOS] Re: Random question about performance

[Grant Edwards]

In gmane.os.ecos.general, you wrote:

> So Redboot isn't a speed demon, I knew that, but pings to redboot take on 
> average 4 - 6 milliseconds. Pings to UNIX running on the same hardware take 
> .4 - .8 milleseconds. That is not quite 10x slower. I know Redboot is a 
> polled networking system but it doesn't have to context switch either. 
> What's up with that?

In some modes, RedBoot only checks for network input once every
10ms.  That means average ping times of around 5ms.  On my
platform, I increased the polling rate to 1-2 ms to make
RedBoot more responsive to network traffic.

-- 
Grant Edwards                   grante             Yow!  How's the wife? Is
                                  at               she at home enjoying
                               visi.com            capitalism?

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