From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx181.postini.com [74.125.245.181]) by kanga.kvack.org (Postfix) with SMTP id 377BF6B0031 for ; Fri, 6 Sep 2013 04:58:26 -0400 (EDT) Received: from /spool/local by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 6 Sep 2013 14:18:50 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id 52CF2394004E for ; Fri, 6 Sep 2013 14:28:02 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay05.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r868wC6h47775846 for ; Fri, 6 Sep 2013 14:28:12 +0530 Received: from d28av02.in.ibm.com (localhost [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r868wCGJ000367 for ; Fri, 6 Sep 2013 14:28:13 +0530 Date: Fri, 6 Sep 2013 16:58:11 +0800 From: Wanpeng Li Subject: Re: [PATCH 00/11] x86, memblock: Allocate memory near kernel image before SRAT parsed. Message-ID: <20130906085811.GA31315@hacker.(null)> Reply-To: Wanpeng Li References: <1377596268-31552-1-git-send-email-tangchen@cn.fujitsu.com> <20130904192215.GG26609@mtj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130904192215.GG26609@mtj.dyndns.org> Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: rjw@sisk.pl, lenb@kernel.org, tglx@linutronix.de, mingo@elte.hu, hpa@zytor.com, akpm@linux-foundation.org, trenn@suse.de, yinghai@kernel.org, jiang.liu@huawei.com, wency@cn.fujitsu.com, laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, mgorman@suse.de, minchan@kernel.org, mina86@mina86.com, gong.chen@linux.intel.com, vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com, riel@redhat.com, jweiner@redhat.com, prarit@redhat.com, zhangyanfei@cn.fujitsu.com, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-acpi@vger.kernel.org Hi Tejun, On Wed, Sep 04, 2013 at 03:22:15PM -0400, Tejun Heo wrote: >Hello, > >On Tue, Aug 27, 2013 at 05:37:37PM +0800, Tang Chen wrote: >> 1. Make memblock be able to allocate memory from low address to high address. >> Also introduce low limit to prevent memblock allocating memory too low. >> >> 2. Improve init_mem_mapping() to support allocate page tables from low address >> to high address. >> >> 3. Introduce "movablenode" boot option to enable and disable this functionality. >> >> PS: Reordering of relocate_initrd() and reserve_crashkernel() has not been done >> yet. acpi_initrd_override() needs to access initrd with virtual address. So >> relocate_initrd() must be done before acpi_initrd_override(). > >I'm expectedly happier with this approach but some overall review >points. > >* I think patch splitting went a bit too far. e.g. it doesn't make > much sense or helps anything to split "introduction of a param" from > "the param doing something". > >* I think it's a lot more complex than necessary. Just implement a > single function - memblock_alloc_bottom_up(@start) where specifying > MEMBLOCK_ALLOC_ANYWHERE restores top down behavior and do > memblock_alloc_bottom_up(end_of_kernel) early during boot. If the > bottom up mode is set, just try allocating bottom up from the > specified address and if that fails do normal top down allocation. > No need to meddle with the callers. The only change necessary > (well, aside from the reordering) outside memblock is adding two > calls to the above function. > >* I don't think "order" is the right word here. "direction" probably > fits a lot better. What's the root reason memblock alloc from high to low? To reduce fragmentation or ... Regards, Wanpeng Li > >Thanks. > >-- >tejun > >-- >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 -- 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