From owner-freebsd-current@FreeBSD.ORG Wed Sep 4 14:34:09 2013 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 23331F09; Wed, 4 Sep 2013 14:34:09 +0000 (UTC) (envelope-from nwhitehorn@freebsd.org) Received: from mail.icecube.wisc.edu (trout.icecube.wisc.edu [128.104.255.119]) by mx1.freebsd.org (Postfix) with ESMTP id D9331284D; Wed, 4 Sep 2013 14:34:08 +0000 (UTC) Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.icecube.wisc.edu (Postfix) with ESMTP id 50CBE5838C; Wed, 4 Sep 2013 09:11:29 -0500 (CDT) X-Virus-Scanned: amavisd-new at icecube.wisc.edu Received: from mail.icecube.wisc.edu ([127.0.0.1]) by localhost (trout.icecube.wisc.edu [127.0.0.1]) (amavisd-new, port 10030) with ESMTP id F6OyxvU8mfj5; Wed, 4 Sep 2013 09:11:29 -0500 (CDT) Received: from terminus.icecube.wisc.edu (terminus.icecube.wisc.edu [172.16.223.97]) by mail.icecube.wisc.edu (Postfix) with ESMTP id 3115758388; Wed, 4 Sep 2013 09:11:29 -0500 (CDT) Message-ID: <52273F90.7020303@freebsd.org> Date: Wed, 04 Sep 2013 09:11:28 -0500 From: Nathan Whitehorn User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:17.0) Gecko/20130809 Thunderbird/17.0.8 MIME-Version: 1.0 To: Ryan Stone Subject: Re: [RFC][CFT] GEOM direct dispatch and fine-grained CAM locking References: <520D4ADB.50209@FreeBSD.org> <5224511D.4090503@FreeBSD.org> <20130903134251.GB43281@caravan.chchile.org> <5226DAB0.1060303@FreeBSD.org> <52272B6F.9060308@freebsd.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-geom@freebsd.org, "freebsd-hackers@freebsd.org" , Alexander Motin , "freebsd-current@freebsd.org" , FreeBSD SCSI , =?ISO-8859-1?Q?Olivier_Cochard?= =?ISO-8859-1?Q?-Labb=E9?= , Outback Dingo 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: Wed, 04 Sep 2013 14:34:09 -0000 On 09/04/13 08:20, Ryan Stone wrote: > On Wed, Sep 4, 2013 at 8:45 AM, Nathan Whitehorn wrote: >> Could you describe what this macro is supposed to do so that we can do the >> porting work? >> -Nathan > #define GET_STACK_USAGE(total, used) > > GET_STACK_USAGE sets the variable passed in total to the total amount > of stack space available to the current thread. used is set to the > amount of stack space currently used (this does not have to have > byte-precision). Netgraph uses this to decide when to stop recursing > and instead defer to a work queue (to prevent stack overflow). I > presume that Alexander is using it in a similar way. It looks like > the amd64 version could be ported to other architectures quite easily > if you were to account for stacks that grow up and stacks that grow > down: > > http://svnweb.freebsd.org/base/head/sys/amd64/include/proc.h?revision=233291&view=markup > > /* Get the current kernel thread stack usage. */ > #define GET_STACK_USAGE(total, used) do { \ > struct thread *td = curthread; \ > (total) = td->td_kstack_pages * PAGE_SIZE; \ > (used) = (char *)td->td_kstack + \ > td->td_kstack_pages * PAGE_SIZE - \ > (char *)&td; \ > } while (0) > _______________________________________________ > 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" I think that should be MI for us anyway. I'm not aware of any architectures FreeBSD supports with stacks that grow up. I'll give it a test on PPC. -Nathan