From owner-freebsd-current@FreeBSD.ORG Fri May 14 18:39:38 2010 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2AFAE1065674; Fri, 14 May 2010 18:39:38 +0000 (UTC) (envelope-from kaduk@mit.edu) Received: from dmz-mailsec-scanner-7.mit.edu (DMZ-MAILSEC-SCANNER-7.MIT.EDU [18.7.68.36]) by mx1.freebsd.org (Postfix) with ESMTP id C35F08FC13; Fri, 14 May 2010 18:39:37 +0000 (UTC) X-AuditID: 12074424-b7b9dae000002832-dd-4bed98e8a5bc Received: from mailhub-auth-3.mit.edu (MAILHUB-AUTH-3.MIT.EDU [18.9.21.43]) by dmz-mailsec-scanner-7.mit.edu (Symantec Brightmail Gateway) with SMTP id 17.44.10290.8E89DEB4; Fri, 14 May 2010 14:39:36 -0400 (EDT) Received: from outgoing.mit.edu (OUTGOING-AUTH.MIT.EDU [18.7.22.103]) by mailhub-auth-3.mit.edu (8.13.8/8.9.2) with ESMTP id o4EIdaib031958; Fri, 14 May 2010 14:39:36 -0400 Received: from multics.mit.edu (MULTICS.MIT.EDU [18.187.1.73]) (authenticated bits=56) (User authenticated as kaduk@ATHENA.MIT.EDU) by outgoing.mit.edu (8.13.6/8.12.4) with ESMTP id o4EIdY0t004977 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Fri, 14 May 2010 14:39:35 -0400 (EDT) Received: (from kaduk@localhost) by multics.mit.edu (8.12.9.20060308) id o4EIdXNQ012240; Fri, 14 May 2010 14:39:33 -0400 (EDT) Date: Fri, 14 May 2010 14:39:32 -0400 (EDT) From: Benjamin Kaduk To: Alan Cox In-Reply-To: <4BED8ADE.1030100@cs.rice.edu> Message-ID: References: <20100514053907.GL83316@deviant.kiev.zoral.com.ua> <4BED8ADE.1030100@cs.rice.edu> User-Agent: Alpine 1.10 (GSO 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII X-Brightmail-Tracker: AAAAAA== Cc: Kostik Belousov , alc@freebsd.org, freebsd-current@freebsd.org Subject: Re: kgdb unuseable with cores on current (for some people) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 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: Fri, 14 May 2010 18:39:38 -0000 On Fri, 14 May 2010, Alan Cox wrote: > On 5/14/2010 1:44 AM, Benjamin Kaduk wrote: >> On Fri, 14 May 2010, Kostik Belousov wrote: >> >>> >>> Try reverting r202897 on fresh HEAD. I very much doubt that r202933 >>> can be responsible. >>> >> >> Indeed, 202933 was cleared of blame in the latest bisection. I'm currently >> pulling up to HEAD and will try reverting 202897. HEAD with 202897 reverted works; HEAD with the patch below does not work Hm, but the "Cannot access memory" is preceeded by "Unread portion of the kernel message buffer:\n"; I don't remember whether that was there before. I'll compile another kernel from stock HEAD to check if that's actually due to the patch (or just poor memory on my part). Any other thoughts, Alan? > > I suspect the following is needed: > > Index: vm/vm_page.c > =================================================================== > --- vm/vm_page.c (revision 207823) > +++ vm/vm_page.c (working copy) > @@ -108,6 +108,7 @@ __FBSDID("$FreeBSD$"); > #include > #include > #include > +#include > #include > #include > #include > @@ -375,6 +376,14 @@ vm_page_startup(vm_offset_t vaddr) > new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE); > bzero((void *)vm_page_dump, vm_page_dump_size); > #endif > +#ifdef __amd64__ > + pa = DMAP_TO_PHYS((vm_offset_t)msgbufp); > + last_pa = pa + round_page(MSGBUF_SIZE); > + while (pa < last_pa) { > + dump_add_page(pa); > + pa += PAGE_SIZE; > + } > +#endif > /* > * Compute the number of pages of memory that will be available for > * use (taking into account the overhead of a page structure per > >