From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yinghai Lu Subject: Re: [PATCH 07/31] lmb: Add reserve_lmb/free_lmb Date: Mon, 29 Mar 2010 17:03:39 -0700 Message-ID: <4BB13FDB.9060006@kernel.org> References: <1269830604-26214-1-git-send-email-yinghai@kernel.org> <1269830604-26214-8-git-send-email-yinghai@kernel.org> <1269865322.24620.42.camel@concordia> <4BB0D92C.3010103@kernel.org> <1269901252.2286.11.camel@concordia> <1269905491.7101.40.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:60698 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752314Ab0C3AFb (ORCPT ); Mon, 29 Mar 2010 20:05:31 -0400 In-Reply-To: <1269905491.7101.40.camel@pasglop> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Benjamin Herrenschmidt Cc: michael@ellerman.id.au, Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Andrew Morton , David Miller , Linus Torvalds , Johannes Weiner , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org On 03/29/2010 04:31 PM, Benjamin Herrenschmidt wrote: > On Tue, 2010-03-30 at 09:20 +1100, Michael Ellerman wrote: >> >> But that's my point. You shouldn't need to touch the existing API, and >> you shouldn't need to add a new parallel API. You should just be able to >> add the logic for doubling the array in the lmb core, and then everyone >> gets dynamically expandable lmb. I don't see any reason why we want to >> have two APIs. > > Ack. ok, we can merge them later. > >>>> It seems to me that rather than adding these "special" routines that >>>> check for enough space on the way in, instead you should be checking in >>>> lmb_add_region() - which is where AFAICS all allocs/frees/reserves >>>> eventually end up if they need to insert a new region. >>> >>> later i prefer to replace lmb_alloc with find_lmb_area + reserve_lmb. >> >> Why? The existing code has been working for years and is well tested? > > I still don't totally understand why he needs a find_lmb_area() > anyways. > > It might be justified ... or not. I just want it to be better > documented. current changelog for that ------------------ Subject: [PATCH 6/31] lmb: Add lmb_find_area() It will try find area according with size/align in specified range (start, end). Need use it find correct buffer for new lmb.reserved.region. also make it more easy for x86 to use lmb. x86 early_res is using find/reserve pattern instead of alloc. lmb_find_area() will honor goal When we need temporary buff for range array etc for range work, if We are using lmb_alloc(), We will need to add some post fix code for buffer that is used by range array, because it is in the lmb.reserved already. ---------------- in short: It could make us to avoid use the range that we are going to reserve, when we try to get new position new lmb.reserved.region. Thanks Yinghai