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From: Richard.Draves@CS.CMU.EDU
Newsgroups: comp.os.mach
Subject: Re: Mach performance? [Long]
Message-ID: <IZYFjfK00hYPB2M7si@cs.cmu.edu>
Date: 21 Dec 89 18:07:39 GMT
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Off-machine RPCs are relatively slow because they aren't handled
directly by the kernel.  A user-level process, called the netmsgserver,
handles network IPC.  When a task on machine A sends a message to a task
on machine B, the message really goes to the netmsgserver on A, which
sends it to the netmsgserver on B, which sends it to the final
destination.  (These intermediaries are transparent to the user tasks on
A & B.  Messages are sent to capabilities which don't have any location
information in their names.)  In sum, not an architecture motivated by
performance.

Rich