nanog mailing list archives

Re: Whats so difficult about ISSU


From: Saku Ytti <saku () ytti fi>
Date: Sat, 10 Nov 2012 00:07:45 +0200

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


Current thread: