From owner-svn-src-head@FreeBSD.ORG Tue Sep 21 16:31:05 2010 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5A46B1065672; Tue, 21 Sep 2010 16:31:05 +0000 (UTC) (envelope-from mdf356@gmail.com) Received: from mail-gx0-f182.google.com (mail-gx0-f182.google.com [209.85.161.182]) by mx1.freebsd.org (Postfix) with ESMTP id ABD978FC17; Tue, 21 Sep 2010 16:31:04 +0000 (UTC) Received: by gxk8 with SMTP id 8so2122247gxk.13 for ; Tue, 21 Sep 2010 09:31:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:sender:received :in-reply-to:references:date:x-google-sender-auth:message-id:subject :from:to:cc:content-type; bh=iQ5Nz+FkyG5J4py/5KlnYON7ZTqt/yIwCYaEH0KD0HU=; b=dwpUet8Xj2bCKgvN7ZMMFRCa5Q6xgPpgcw8KnE8OgTqs3AGuDPGeFkyuYPGt466NxU gSs8VQqkSvtMVHJpaq7As5/SkNieOoiGQdPojXfZKZKQlhmdIs1s/z7ty9og8IlIYJmn 0j0ueDcxm14rvlKKotMqvfPuuAjNQDqqat158= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=VYdz8sfQl2ca+WbujWNf52AV1omNWzQvqzyX57aEtBp7Eq/OwKvItZEqN/156+1QgJ ABIl2sEjzyXho/ulNGOBuMizwBUGxQ/HyP6ykc3vr2cUpSVPEkqzVmIuIp38JkwT18Zq GLT2fiBVRT6p22ED8OKvfk/VU2D7+Q07kodQ4= MIME-Version: 1.0 Received: by 10.90.95.14 with SMTP id s14mr6148150agb.161.1285086662059; Tue, 21 Sep 2010 09:31:02 -0700 (PDT) Sender: mdf356@gmail.com Received: by 10.231.187.71 with HTTP; Tue, 21 Sep 2010 09:31:01 -0700 (PDT) In-Reply-To: <4C98D200.4040909@freebsd.org> References: <201009211507.o8LF7iVv097676@svn.freebsd.org> <4C98CEE7.6060802@freebsd.org> <4C98D200.4040909@freebsd.org> Date: Tue, 21 Sep 2010 09:31:01 -0700 X-Google-Sender-Auth: wQNN5cZynoYNuE0IR25Aj5e-N44 Message-ID: From: mdf@FreeBSD.org To: Andriy Gapon Content-Type: text/plain; charset=ISO-8859-1 Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r212964 - head/sys/kern X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 21 Sep 2010 16:31:05 -0000 On Tue, Sep 21, 2010 at 8:40 AM, Andriy Gapon wrote: > on 21/09/2010 18:27 Andriy Gapon said the following: >> on 21/09/2010 18:17 mdf@FreeBSD.org said the following: >>> >>> I'd recommend using stack_print_ddb(), as that avoids any locking >>> which may hang depending on how the kernel panic'd. >> >> It seems that stack_print_ddb() depends on DDB? > > But the point about locking is very good. > How do you suggest we can deal with it? > > A dirty hack would be to check panicstr in linker_search_symbol_name and avoid > locking, but I don't like that at all. > Perhaps, some code in subr_stack.c could be taken outside DDB ifdef? I keep forgetting, but actually _mtx_lock_sleep() will just return if panicstr is set. _mtx_assert() is similarly guarded, so actually it should be mostly okay. Thanks, matthew