From owner-freebsd-arch@FreeBSD.ORG  Thu Nov 15 23:17:10 2012
Return-Path: <owner-freebsd-arch@FreeBSD.ORG>
Delivered-To: freebsd-arch@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
 by hub.freebsd.org (Postfix) with ESMTP id A74409BA;
 Thu, 15 Nov 2012 23:17:10 +0000 (UTC) (envelope-from bright@mu.org)
Received: from elvis.mu.org (elvis.mu.org [192.203.228.196])
 by mx1.freebsd.org (Postfix) with ESMTP id 75A2C8FC08;
 Thu, 15 Nov 2012 23:17:10 +0000 (UTC)
Received: from kruse-124.4.ixsystems.com (drawbridge.ixsystems.com
 [206.40.55.65])
 by elvis.mu.org (Postfix) with ESMTPSA id 4B4B61A3D8D;
 Thu, 15 Nov 2012 15:17:04 -0800 (PST)
Message-ID: <50A57815.4060104@mu.org>
Date: Thu, 15 Nov 2012 15:17:41 -0800
From: Alfred Perlstein <bright@mu.org>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7;
 rv:16.0) Gecko/20121026 Thunderbird/16.0.2
MIME-Version: 1.0
To: Adrian Chadd <adrian@freebsd.org>
Subject: Re: [RFQ] make witness panic an option
References: <CAJ-Vmo=i=Amo_QqHi4GnGie0Gc0YnK3XaRKjvBO-=SFboFYPmA@mail.gmail.com>
In-Reply-To: <CAJ-Vmo=i=Amo_QqHi4GnGie0Gc0YnK3XaRKjvBO-=SFboFYPmA@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Content-Filtered-By: Mailman/MimeDel 2.1.14
Cc: freebsd-hackers@freebsd.org, freebsd-arch@freebsd.org
X-BeenThere: freebsd-arch@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Discussion related to FreeBSD architecture <freebsd-arch.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-arch>,
 <mailto:freebsd-arch-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-arch>
List-Post: <mailto:freebsd-arch@freebsd.org>
List-Help: <mailto:freebsd-arch-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
 <mailto:freebsd-arch-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 15 Nov 2012 23:17:10 -0000

On 11/14/12 10:15 PM, Adrian Chadd wrote:
> Hi all,
>
> When debugging and writing wireless drivers/stack code, I like to
> sprinkle lots of locking assertions everywhere. However, this does
> cause things to panic quite often during active development.
>
> This patch (against stable/9) makes the actual panic itself
> configurable. It still prints the message regardless.
>
> This has allowed me to sprinkle more locking assertions everywhere to
> investigate whether particular paths have been hit or not. I don't
> necessarily want those to panic the kernel.
>
> I'd like everyone to consider this for FreeBSD-HEAD.
>
> Thanks!

Adrian, you seem be getting reluctance on your patch which is surprising 
since we have "witness_kdb" option which pretty much does exactly what 
you want...

...except where you need it to.  That is unfortunate.

Perhaps if you switched those panics to a WITNESS_WARN that would do 
what you need/want?

You could pass a special flag into WITNESS_WARN that said "i'm going to 
pass you a NULL ptr for lock object... just behave as if there was an 
error".

that should make things more concise.

Will that be sufficient?

-Alfred

>
>
>
> Adrian
>
>
> _______________________________________________
> freebsd-hackers@freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-hackers
> To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org"