From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f48.google.com (mail-pa0-f48.google.com [209.85.220.48]) by kanga.kvack.org (Postfix) with ESMTP id 5D5506B0033 for ; Mon, 23 Sep 2013 12:04:41 -0400 (EDT) Received: by mail-pa0-f48.google.com with SMTP id bj1so2461926pad.21 for ; Mon, 23 Sep 2013 09:04:41 -0700 (PDT) Received: by mail-yh0-f44.google.com with SMTP id f64so1380229yha.17 for ; Mon, 23 Sep 2013 08:39:00 -0700 (PDT) Date: Mon, 23 Sep 2013 11:38:53 -0400 From: Tejun Heo Subject: Re: [PATCH v3 1/5] memblock: Introduce allocation direction to memblock. Message-ID: <20130923153853.GC14547@htj.dyndns.org> References: <1379064655-20874-1-git-send-email-tangchen@cn.fujitsu.com> <1379064655-20874-2-git-send-email-tangchen@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1379064655-20874-2-git-send-email-tangchen@cn.fujitsu.com> Sender: owner-linux-mm@kvack.org List-ID: To: Tang Chen Cc: rjw@sisk.pl, lenb@kernel.org, tglx@linutronix.de, mingo@elte.hu, hpa@zytor.com, akpm@linux-foundation.org, toshi.kani@hp.com, zhangyanfei@cn.fujitsu.com, liwanp@linux.vnet.ibm.com, 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, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-acpi@vger.kernel.org Hello, Sorry about the delay. Was traveling. On Fri, Sep 13, 2013 at 05:30:51PM +0800, Tang Chen wrote: > +/* Allocation order. */ > +#define MEMBLOCK_DIRECTION_HIGH_TO_LOW 0 > +#define MEMBLOCK_DIRECTION_LOW_TO_HIGH 1 > +#define MEMBLOCK_DIRECTION_DEFAULT MEMBLOCK_DIRECTION_HIGH_TO_LOW Can we please settle on either top_down/bottom_up or high_to_low/low_to_high? The two seem to be used interchangeably in the patch series. Also, it'd be more customary to use enum for things like above, but more on the interface below. > +static inline bool memblock_direction_bottom_up(void) > +{ > + return memblock.current_direction == MEMBLOCK_DIRECTION_LOW_TO_HIGH; > +} Maybe just memblock_bottom_up() would be enough? Also, why not also have memblock_set_bottom_up(bool enable) as the 'set' interface? > /** > + * memblock_set_current_direction - Set current allocation direction to allow > + * allocating memory from higher to lower > + * address or from lower to higher address > + * > + * @direction: In which order to allocate memory. Could be > + * MEMBLOCK_DIRECTION_{HIGH_TO_LOW|LOW_TO_HIGH} > + */ > +void memblock_set_current_direction(int direction); Function comments should go with the function definition. Dunno what happened with set_current_limit but let's please not spread it. > +void __init_memblock memblock_set_current_direction(int direction) > +{ > + if (direction != MEMBLOCK_DIRECTION_HIGH_TO_LOW && > + direction != MEMBLOCK_DIRECTION_LOW_TO_HIGH) { > + pr_warn("memblock: Failed to set allocation order. " > + "Invalid order type: %d\n", direction); > + return; > + } > + > + memblock.current_direction = direction; > +} If set_bottom_up() style interface is used, the above will be a lot simpler, right? Also, it's kinda weird to have two separate patches to introduce the flag and actually implement bottom up allocation. 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