Whats so difficult about ISSU

Saku Ytti saku at ytti.fi
Fri Nov 9 22:07:45 UTC 2012


On (2012-11-09 16:58 -0500), Pete Lumbis wrote:
 
> I do not believe that the linux scheduler is run to completion, but to
> be honest I'm not 100% certain. I know a big reason for IOS-XE was to

It certainly is not, I'm not proposing it is. I'm saying it is bit of a
stretch to believe that IOSd does not have own legacy scheduler and memory
management as pulling that switch would have been quite major rework.

> be able to operate in multicore environments. From a high level you
> have IOSd as a process with each traditional process (BGP, OSPF, IP
> Input) as a thread within IOSd. Overall IOS-XE is Linux managing a few
> processes: IOSd, FMan-RP, CMan-RP (and a few others) FMan deals with
> adjacencies and CMan deals with modules/cards and IOSd all the
> interesting stuff. Since Linux is the piece actually running the show
> IOS-XE gets all the memory management and scheduling benefits that
> linux has.

So each IOSd process 'show proc cpu' are separate threads to linux?

-- 
  ++ytti




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