From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx174.postini.com [74.125.245.174]) by kanga.kvack.org (Postfix) with SMTP id 2E5F96B006C for ; Wed, 14 Nov 2012 12:39:36 -0500 (EST) Date: Wed, 14 Nov 2012 17:39:28 +0000 From: Russell King - ARM Linux Subject: Re: [RFC PATCH 0/3] introduce static_vm for ARM-specific static mapped area Message-ID: <20121114173928.GK3290@n2100.arm.linux.org.uk> References: <1352912154-16210-1-git-send-email-js1304@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1352912154-16210-1-git-send-email-js1304@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org On Thu, Nov 15, 2012 at 01:55:51AM +0900, Joonsoo Kim wrote: > In current implementation, we used ARM-specific flag, that is, > VM_ARM_STATIC_MAPPING, for distinguishing ARM specific static mapped area. > The purpose of static mapped area is to re-use static mapped area when > entire physical address range of the ioremap request can be covered > by this area. > > This implementation causes needless overhead for some cases. In what cases? > We unnecessarily iterate vmlist for finding matched area even if there > is no static mapped area. And if there are some static mapped areas, > iterating whole vmlist is not preferable. Why not? Please put some explanation into your message rather than just statements making unexplained assertions. > Another reason for doing this work is for removing architecture dependency > on vmalloc layer. I think that vmlist and vmlist_lock is internal data > structure for vmalloc layer. Some codes for debugging and stat inevitably > use vmlist and vmlist_lock. But it is preferable that they are used outside > of vmalloc.c as least as possible. The vmalloc layer is also made available for ioremap use, and it is intended that architectures hook into this for ioremap support. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org