Date: Thu, 11 Mar 1999 02:50:01 -0800 (PST) From: Andreas Klemm <andreas@klemm.gtn.com> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/10535: Very poor ethernet performance with tx driver Message-ID: <199903111050.CAA51115@freefall.freebsd.org>
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The following reply was made to PR kern/10535; it has been noted by GNATS. From: Andreas Klemm <andreas@klemm.gtn.com> To: Peter Jeremy <peter.jeremy@AUSS2.ALCATEL.COM.AU> Cc: dfr@nlsystems.com, FreeBSD-gnats-submit@FreeBSD.ORG, andreas@FreeBSD.ORG Subject: Re: kern/10535: Very poor ethernet performance with tx driver Date: Thu, 11 Mar 1999 11:22:03 +0100 On Thu, Mar 11, 1999 at 08:01:22PM +1000, Peter Jeremy wrote: > Doug Rabson <dfr@nlsystems.com> wrote: > >The fix looks correct to me but as DG noted when the last change was made > >to this driver, it should be using DELAY to avoid future problems with > >processor speeds. > > I think that's a separate issue. The current code is incorrect because > references to H/W registers aren't marked volatile - and are therefore > likely to be optimised away. Andreas' change made the problem show > up because of the extra delay. I'm surprised that the only symptom > was poor performance. And a huge amount of sys time (top: 90% sys, 0-10% idle) when 30 telnet sessions using nc (netcat) were running concurrently. When typing something on the console, then the characters were a bit delayed .. Andreas /// -- Andreas Klemm http://www.FreeBSD.ORG/~andreas What gives you 90% more speed, for example, in kernel compilation ? http://www.FreeBSD.ORG/~fsmp/SMP/akgraph-a/graph1.html "NT = Not Today" (Maggie Biggs) ``powered by FreeBSD SMP'' To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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