From owner-freebsd-mips@FreeBSD.ORG Sat Sep 6 22:28:58 2014 Return-Path: Delivered-To: freebsd-mips@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 0AD45AD; Sat, 6 Sep 2014 22:28:58 +0000 (UTC) Received: from pp1.rice.edu (proofpoint1.mail.rice.edu [128.42.201.100]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id C0AA31D53; Sat, 6 Sep 2014 22:28:57 +0000 (UTC) Received: from pps.filterd (pp1.rice.edu [127.0.0.1]) by pp1.rice.edu (8.14.5/8.14.5) with SMTP id s86MSnoD009493; Sat, 6 Sep 2014 17:28:49 -0500 Received: from mh3.mail.rice.edu (mh3.mail.rice.edu [128.42.199.10]) by pp1.rice.edu with ESMTP id 1p68ec9tbh-1; Sat, 06 Sep 2014 17:28:49 -0500 X-Virus-Scanned: by amavis-2.7.0 at mh3.mail.rice.edu, auth channel Received: from 108-254-203-201.lightspeed.hstntx.sbcglobal.net (108-254-203-201.lightspeed.hstntx.sbcglobal.net [108.254.203.201]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (No client certificate requested) (Authenticated sender: alc) by mh3.mail.rice.edu (Postfix) with ESMTPSA id 331C54013D; Sat, 6 Sep 2014 17:28:49 -0500 (CDT) Message-ID: <540B8AA0.40005@rice.edu> Date: Sat, 06 Sep 2014 17:28:48 -0500 From: Alan Cox User-Agent: Mozilla/5.0 (X11; FreeBSD i386; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Adrian Chadd , "freebsd-mips@freebsd.org" , Alan Cox , Gleb Smirnoff Subject: Re: bug 193400: sfbuf changes on mips32 may have exposed some vm/pmap issues on mips32? References: In-Reply-To: X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 kscore.is_bulkscore=0 kscore.compositescore=0 circleOfTrustscore=0 compositescore=0.713890987064109 urlsuspect_oldscore=0.713890987064109 suspectscore=3 recipient_domain_to_sender_totalscore=0 phishscore=0 bulkscore=0 kscore.is_spamscore=1 recipient_to_sender_totalscore=0 recipient_domain_to_sender_domain_totalscore=0 rbsscore=0.713890987064109 spamscore=0 recipient_to_sender_domain_totalscore=0 urlsuspectscore=0.9 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1402240000 definitions=main-1409060259 X-BeenThere: freebsd-mips@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Porting FreeBSD to MIPS List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 06 Sep 2014 22:28:58 -0000 On 09/06/2014 17:24, Adrian Chadd wrote: > Hi! > > This bug: > > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=193400 > > is what I reported to alc a couple weeks ago as breaking on my 128mb > RAM mipsbe board. > > It turns out that the difference between the MIPS32 sfbuf code and the > new stuff gleb added was the refcounting side of things. With the MIPS > code, there was no refcounting at all - each sfbuf allocation would > allocate a new sfbuf. Now, I don't know how correct that is (my > reading of the code is "not correct!") but it wasn't panicing things. > > So I think maybe gleb's patch to sfbuf exposed a MIPS32 pmap/VM bug? > > Alan - how would we go about figuring out what could be the issue here? I just sent you an email a few minutes ago describing how to restore the old behavior. > I'd really appreciate some help here as I'd like to keep the MIPS32 > stuff in good shape. :) > > Thanks! > > > -a >