From owner-freebsd-current@freebsd.org Thu Aug 31 11:12:37 2017 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 2110CE1C13A; Thu, 31 Aug 2017 11:12:37 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from hz.grosbein.net (hz.grosbein.net [78.47.246.247]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "hz.grosbein.net", Issuer "hz.grosbein.net" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id A8FA073A86; Thu, 31 Aug 2017 11:12:36 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from eg.sd.rdtc.ru (root@eg.sd.rdtc.ru [62.231.161.221] (may be forged)) by hz.grosbein.net (8.15.2/8.15.2) with ESMTPS id v7VBCUhj044682 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 31 Aug 2017 13:12:31 +0200 (CEST) (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: ycyc321@gmail.com Received: from eg.sd.rdtc.ru (eugen@localhost [127.0.0.1]) by eg.sd.rdtc.ru (8.15.2/8.15.2) with ESMTP id v7VBCQg4021630; Thu, 31 Aug 2017 18:12:26 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: How to know the address ranges of kernel stacks, for user processes and kernel threads? To: Yue Chen , freebsd-hackers@freebsd.org, freebsd-current@freebsd.org References: From: Eugene Grosbein Message-ID: <59A7EF1A.7020502@grosbein.net> Date: Thu, 31 Aug 2017 18:12:26 +0700 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Spam-Status: Yes, score=5.5 required=5.0 tests=BAYES_00, DATE_IN_FUTURE_96_Q, LOCAL_FROM,RDNS_NONE autolearn=no autolearn_force=no version=3.4.1 X-Spam-Report: * 3.3 DATE_IN_FUTURE_96_Q Date: is 4 days to 4 months after Received: date * -2.3 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * 1.9 RDNS_NONE Delivered to internal network by a host with no rDNS * 2.6 LOCAL_FROM From my domains X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on hz.grosbein.net X-Spam-Flag: YES X-Spam-Level: ***** X-Mailman-Approved-At: Thu, 31 Aug 2017 17:41:34 +0000 X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.23 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: Thu, 31 Aug 2017 11:12:37 -0000 On 29.01.2015 07:54, Yue Chen wrote: > It seems that each kernel stack has two pages (IA-32) to use. Does x86_64 > still have two pages or more? One can change number of kernel stack pages for i386 and amd64 platforms by means of /boot/loader.conf without need to rebuild a kernel using kern.kstack_pages tunnable. It equals to 2 for i386 and to 4 for amd64 by default but I change it from 2 to 4 for my i386 systems running IPSEC tunnels and/or wifi due to these subsystems being stack-greedy. See also https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=219476