From owner-freebsd-current@FreeBSD.ORG Sat Feb 9 17:53:41 2013 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 8C0C86D5 for ; Sat, 9 Feb 2013 17:53:41 +0000 (UTC) (envelope-from venture37@gmail.com) Received: from mail-la0-x22a.google.com (la-in-x022a.1e100.net [IPv6:2a00:1450:4010:c03::22a]) by mx1.freebsd.org (Postfix) with ESMTP id 1B0EB6EB for ; Sat, 9 Feb 2013 17:53:40 +0000 (UTC) Received: by mail-la0-f42.google.com with SMTP id fe20so4758136lab.15 for ; Sat, 09 Feb 2013 09:53:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:message-id:date:from:user-agent:mime-version:to:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=J99Dq5lU9h9e7rxq5lfc4J58OPibgE+2R68+HoU/TbU=; b=cNFRy9APH6FFBjTKv3r3mLTEDriXdzo/18BEtQ8QtnKb4dCY/E72UEfYNpxiKx+Q5z mVWMogwIsmN5D6aqKHa74TgPURSpVCDitAAfkLHVQtzojMa0xtM0XQaPIJYm2zBboeH3 0IwNoqVyOty8go9sjlmpeNFsx8Fi2m7gbgIKrvTcOpTjXlLHLdrXxe9glK1fxe3wFUXu X5b09abjkmEeWzrcf+TrN0JhbtyLTfQCtLiCHUfWU0Sj04HZwlRCA00aM1xSf1wPwJCE GkY7A9rL4CJi9xaYHs1zjL+ve1s0/e7A2GxUgYCSo1EVCwjZ5KslxDaxfEROFCw0NTZm N91Q== X-Received: by 10.152.122.100 with SMTP id lr4mr8316890lab.28.1360432418959; Sat, 09 Feb 2013 09:53:38 -0800 (PST) Received: from Sevans-MacBook-Pro.local ([83.167.125.235]) by mx.google.com with ESMTPS id ie3sm18849728lab.4.2013.02.09.09.53.36 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sat, 09 Feb 2013 09:53:37 -0800 (PST) Message-ID: <51168CD5.5050907@gmail.com> Date: Sat, 09 Feb 2013 21:52:21 +0400 From: Sevan / Venture37 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/20130107 Thunderbird/17.0.2 MIME-Version: 1.0 To: freebsd-current@freebsd.org Subject: Re: [patch] Userland DTrace References: <51152216.9080905@icritical.com> In-Reply-To: <51152216.9080905@icritical.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 Feb 2013 17:53:41 -0000 On 08/02/2013 20:04, Matt Burke wrote: > I've been spending some time trying to get the fasttrap provider to work > on FreeBSD without panicing. I believe I have succeeded, at least to the > point where it's no longer panicing. > > There were two panic causes. The first was > http://www.freebsd.org/cgi/query-pr.cgi?pr=165541 - the FreeBSD port of > fasttrap.c caused ftp_rcount to be left >0. To fix this I've got rid of > the early return and reverted to the opensolaris way. > > A second panic then showed up intermittently when fasttrap_pid_cleanup_cb > was run while something in userland had locks. Using sx_try_xlock calls > has stopped the panics and shouldn't affect operation AFAICT. > > This is against r246454. > > > Although this has fixed the panics for me, I'm finding a lot of stuff just > isn't actually working, with dtrace and the traced process just chewing > CPU. Truss on the dtrace shows a heck of a lot of ptrace() calls and I > have no idea what the target is doing... CPU time is split 2:1 > dtrace:target > > > Also noteworthy is the LOR on the first time you try to use the fasttrap > provider: http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/165479 > > The lock order there seems right, so I'm guessing "something else" must > have done it wrong first? How can I find out what the "something else" > is? Hi Matt, It might be worth posting the question to the dtrace list if your question is unanswered. http://dtrace.org/blogs/mailing-list/ Regards, Sevan