Subject: Re: emulation speeds?
To: Frank van der Linden <frank@fwi.uva.nl>
From: David Jones <dej@eecg.toronto.edu>
List: current-users
Date: 08/17/1995 10:33:16
> For Linux binaries, there are 2 issues:
>     1. Loading the binary might take longer, because the Linux shared libs
>        may have to be loaded (if this is the first Linux binary you run). For
>        NetBSD binaries you won't really notice this, because the shared
>        libs have been mapped sometime during system startup when the first
>        shared binary was run. Also some Linux binaries can't be demand paged
>        currently.

Is this completely true?

It might have changed recently, but if I remember correctly, the shared libs
used to be mapped into an application's address space, and then the application
itself was patched to perform the link.  This of course causes countless
COW faults on the application itself, so the app must be reloaded each time
it is run.  In contrast, SunOS constructs a jump table to minimize what
needs to be reloaded.

All I know is that even with 8M RAM, NetBSD sucks big time performance-wise
on my Amiga.  Merging VM and buffer cache may help a little, going to SunOS-
style shared libraries if we aren't there already would help more.

-- 
David Jones, M.A.Sc student, Electronics Group (VLSI), University of Toronto
           email: dej@eecg.toronto.edu, finger for PGP public key
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