From owner-cvs-all  Mon Jan 15 22:16:30 2001
Delivered-To: cvs-all@freebsd.org
Received: from gratis.grondar.za (grouter.grondar.za [196.7.18.65])
	by hub.freebsd.org (Postfix) with ESMTP
	id 2E3A237B400; Mon, 15 Jan 2001 22:16:05 -0800 (PST)
Received: from grondar.za (root@gratis.grondar.za [196.7.18.133])
	by gratis.grondar.za (8.11.1/8.11.1) with ESMTP id f0G6FsI31623;
	Tue, 16 Jan 2001 08:15:57 +0200 (SAST)
	(envelope-from mark@grondar.za)
Message-Id: <200101160615.f0G6FsI31623@gratis.grondar.za>
To: John Baldwin <jhb@FreeBSD.org>, jake@FreeBSD.org
Cc: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org
Subject: Re: cvs commit: src/sys/i386/include atomic.h 
References: <XFMail.010115194211.jhb@FreeBSD.org> 
In-Reply-To: <XFMail.010115194211.jhb@FreeBSD.org> ; from John Baldwin <jhb@FreeBSD.org>  "Mon, 15 Jan 2001 19:42:11 PST."
Date: Tue, 16 Jan 2001 08:15:55 +0200
From: Mark Murray <mark@grondar.za>
Sender: owner-cvs-all@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

> > This has really helped my SMP stability here locally.  The quad xeon has now
> > built 4 releases back to back w/o any problems.  It never made it through 2
> > without locking up before.
> 
> Well, I've tried to stress test all my SMP test machines today.  No lockups so
> far.  The quad xeon did have a problem with a -j 1024 world though (make got a
> bus error).  No console messages though so not sure what that was about.  My
> dual p3-600 had been locking up really bad this past week, but it has had 0
> problems today with this fix.  If other people with SMP can test -current as of
> this patch and report any lockups, that would be helpful.

Cool! :-)

The other day, we were talking about the random_harvest stuff on IRC,
and Jake said that he wanted the harvesting to be less expensive. One of the
things Jake wanted was the mutexes removed. Are mutexes really that expensive,
particularly if I just do a

if (mutex_try_enter(foo, ...)) {
	/* Harvest */
	:
	mutex_exit(foo, ...);
}

How much of a difference would it make if I were to use atomic ops like

if (atomic_cmpset(foo, 0, 1)) {
	/* harvest */
	:
	foo = 0;
}

??

TIA

M
-- 
Mark Murray
Warning: this .sig is umop ap!sdn


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message