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From: gh3@mentor.cc.purdue.edu (Gerrit Huizenga)
Newsgroups: comp.sys.next
Subject: Re: NeXT machines are here: my current bug list
Message-ID: <772@mentor.cc.purdue.edu>
Date: 23 Dec 88 06:35:22 GMT
References: <3048@haven.umd.edu> <8474@pasteur.Berkeley.EDU>
Reply-To: gh3@mentor.cc.purdue.edu (Gerrit Huizenga)
Distribution: na
Organization: Purdue University Computing Center
Lines: 21

In article <8474@pasteur.Berkeley.EDU> jdi@camelot.UUCP (John Irwin) writes:
>
>Speaking of which, has anyone else noticed that when booting the machine prints
>"Allocating 16 buffers (.12 Mb)"?  On a Sun (OS<4.0) the "16" is the total
>number of memory disk buffers.  I sure hope this isn't the case in Mach...
>Anyone know if Mach uses the standard 4.[23]BSD buffer mechanism?
>
>If it's really the total disk buffer pool this could be the cause for the
>somewhat disappointing I/O performance.
>
>	-- John

While going through a set up exercise with the NeXT machines I noticed
the same thing and asked one of the guys from NeXT about this.  He
said that files are memory mapped and in general there is little need
for a pool of standard bufs.  This is a side-effect of MACH rather
than NeXT's implementation if I understand correctly.  If he is correct,
this shouldn't have any direct effect on performance.

Gerrit Huizenga, Purdue University Computing Center
gh3@mentor.cc.purdue.edu