On Thu, Sep 05, 2002 at 02:04:05AM +0400, Dmitry Morozovsky wrote:
> On Wed, 4 Sep 2002, Dominic Marks wrote:
> 
> DM> An mbuf is a fixed length structure which contains network data.
> DM>
> DM> An mbuf cluster is associated with an area of memory which is used for
> DM> storing more data than you can fit in a single mbuf.
> DM>
> DM> According the D&I 4.4 an mbuf is 128 bytes and (not all of this is
> DM> available for data storage), an mbuf cluster varies in size, but
> DM> defaults to 1024 bytes (but according to the book this may be different
> DM> depending on CPU architecture).
> 
> AFAIK according to /usr/src/sys/*/param.h, mbuf size if 256 (at least for
> i386, see /usr/src/sys/i386/include/param.h, and is not defined for
> Alphas);
> 
> and mbcluster size defaults to 2k (I suppose the smallest 2^x to
> cover standard Ethernet frame)
> 
> however, in /usr/src/sys/i386/boot/dosboot/param.h, MCLBYTES defined as
> 2^12 (4k). Don't know whether this value is really used.

I would not be surprised to find that these are the current values. I
quoted directly from the book which is a bit old.

> Sincerely,
> D.Marck                                   [DM5020, DM268-RIPE, DM3-RIPN]
> ------------------------------------------------------------------------
> *** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- [EMAIL PROTECTED] ***
> ------------------------------------------------------------------------
> 

-- 
Dominic Marks
 Computer & Politics Geek
  [work]::[npl.co.uk] << dominic.marks at npl.co.uk >>
  [educ]::[umist.ac.uk] << notyet-known at umist.ac.uk >>
  [home]::[btinternet] << dominic_marks at btinternet.com >>

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