From owner-freebsd-current Thu Feb 14 0:54:28 2002 Delivered-To: freebsd-current@freebsd.org Received: from patrocles.silby.com (d125.as7.nwbl0.wi.voyager.net [169.207.128.253]) by hub.freebsd.org (Postfix) with ESMTP id 25D4637B417 for ; Thu, 14 Feb 2002 00:54:25 -0800 (PST) Received: from localhost (silby@localhost) by patrocles.silby.com (8.11.6/8.11.6) with ESMTP id g1E2wGd09943 for ; Thu, 14 Feb 2002 02:58:19 GMT (envelope-from silby@silby.com) X-Authentication-Warning: patrocles.silby.com: silby owned process doing -bs Date: Thu, 14 Feb 2002 02:58:16 +0000 (GMT) From: Mike Silbersack To: current@freebsd.org Subject: Newbie ddb question Message-ID: <20020214025151.E9922-100000@patrocles.silby.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG I've been poking around in ddb in an attempt to work on some forkbomb/low memory problems, and I've found it extremely useful. There's one thing I can't figure out how to do that would be useful, though. Say that I have a process of interest tsleeping. Is there some way for me to get a backtrace of that process at the time it entered tsleep? In the case I'm creating, many processes are tsleeping on vmwait. As there are multiple places where such a wait can occur, I'd really like to see which codepaths are causing processes to enter that state. The trace command doesn't seem to have the necessary functionality to do this, so I was thinking that I might be able to simulate such an effect by putting a null pointer reference right before such calls, thereby creating a panic. Is this the best way to go, or is there some easier way to accomplish a similar effect? Thanks, Mike "Silby' Silbersack To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message