From owner-freebsd-hackers@FreeBSD.ORG Sat Sep 20 07:07:34 2014 Return-Path: Delivered-To: freebsd-hackers@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 ESMTPS id DCBB9A15 for ; Sat, 20 Sep 2014 07:07:34 +0000 (UTC) Received: from ustc.edu.cn (email6.ustc.edu.cn [IPv6:2001:da8:d800::8]) by mx1.freebsd.org (Postfix) with ESMTP id 26C84791 for ; Sat, 20 Sep 2014 07:07:33 +0000 (UTC) Received: from btw ( [58.211.218.74] ) by ajax-webmail-mailweb (Coremail) ; Sat, 20 Sep 2014 15:07:30 +0800 (CST) Date: Sat, 20 Sep 2014 15:07:30 +0800 (CST) From: btw@mail.ustc.edu.cn To: freebsd-hackers@freebsd.org Message-ID: <1473289.768021411196850376.JavaMail.coremail@mailweb> Subject: What's the difference between kmem_arena and kernel_arena? MIME-Version: 1.0 Content-Type: text/plain; charset=GBK Content-Transfer-Encoding: 7bit X-Originating-IP: [58.211.218.74] X-Priority: 3 X-Mailer: Coremail Webmail Server Version XT_U3b build 111111(15684.4153.3993) Copyright (c) 2002-2014 www.mailtech.cn ustc-xl X-CM-TRANSID: yia_0ZDLTQayJx1UAJDQAw--.20798W X-CM-SenderInfo: xewzqzxdloh3xvwfhvlgxou0/1tbiAQUNAUqSOCd6rwAAsa X-Coremail-Antispam: 1U50xBIdaVrnn0S07vEb7Iv0xC_Ar1lV2xY67kC6x804xJvcS sGvfC2KfnxnUU== X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 20 Sep 2014 07:07:34 -0000 Hi All, There are two similar variables declared in vm/vm_kern.h, they are kernel_arena and kmem_arena. Both of them are used in kmem_malloc(): rv = kmem_back((vmem == kmem_arena) ? kmem_object : kernel_object, I'm wondering what's the difference between them. Why both of them are needed? I have done a lot of searching, but I still can not find an answer. Thanks in advance! - twb