Xref: utzoo comp.unix.wizards:11035 comp.os.misc:508
Path: utzoo!attcan!uunet!husc6!rutgers!bellcore!tness7!texbell!bigtex!james
From: james@bigtex.uucp (James Van Artsdalen)
Newsgroups: comp.unix.wizards,comp.os.misc
Subject: shared libraries (was tracing system calls)
Message-ID: <7804@bigtex.uucp>
Date: 10 Sep 88 00:06:51 GMT
References: <21606@ccicpg.UUCP> <7622@boring.cwi.nl> <2040@cuuxb.ATT.COM> <7716@bigtex.uucp> <67440@sun.uucp>
Reply-To: james@bigtex.UUCP (James Van Artsdalen)
Organization: F.B.N. Software, Austin TX
Lines: 18

In article <67440@sun.uucp>, guy@gorodish.Sun.COM (Guy Harris) wrote:

> S5R3 does it in the kernel.  SunOS 4.0 does it in user mode.  [...]

> It also means it's easier to make it more powerful; the SunOS shared
> libraries are not tied to specific locations, and relocation is done
> when the library is mapped in.

What are the performance trade-offs here?  All of Sun's hardware may
support position independent code, but I wonder what the expense would
be of actually relocating the library code on each and every exec() on
a processor where all branches are absolutely addressed.

How do the two schemes fair under existing hardware?  Does it make a
significant difference in the real world?
-- 
James R. Van Artsdalen    ...!uunet!utastro!bigtex!james     "Live Free or Die"
Home: 512-346-2444 Work: 328-0282; 110 Wild Basin Rd. Ste #230, Austin TX 78746