From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f44.google.com (mail-pa0-f44.google.com [209.85.220.44]) by kanga.kvack.org (Postfix) with ESMTP id 3BF776B0036 for ; Thu, 26 Sep 2013 10:45:24 -0400 (EDT) Received: by mail-pa0-f44.google.com with SMTP id lf10so1400938pab.31 for ; Thu, 26 Sep 2013 07:45:23 -0700 (PDT) Received: by mail-ye0-f169.google.com with SMTP id r13so419047yen.14 for ; Thu, 26 Sep 2013 07:45:21 -0700 (PDT) Date: Thu, 26 Sep 2013 10:45:16 -0400 From: Tejun Heo Subject: Re: [PATCH v5 2/6] memblock: Introduce bottom-up allocation mode Message-ID: <20130926144516.GD3482@htj.dyndns.org> References: <5241D897.1090905@gmail.com> <5241D9A4.4080305@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5241D9A4.4080305@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Zhang Yanfei Cc: "Rafael J . Wysocki" , lenb@kernel.org, Thomas Gleixner , mingo@elte.hu, "H. Peter Anvin" , Andrew Morton , Toshi Kani , Wanpeng Li , Thomas Renninger , Yinghai Lu , Jiang Liu , Wen Congyang , Lai Jiangshan , isimatu.yasuaki@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, Mel Gorman , Minchan Kim , mina86@mina86.com, gong.chen@linux.intel.com, vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com, Rik van Riel , jweiner@redhat.com, prarit@redhat.com, "x86@kernel.org" , linux-doc@vger.kernel.org, "linux-kernel@vger.kernel.org" , Linux MM , linux-acpi@vger.kernel.org, imtangchen@gmail.com, Zhang Yanfei Hello, On Wed, Sep 25, 2013 at 02:27:48AM +0800, Zhang Yanfei wrote: > +#ifdef CONFIG_MOVABLE_NODE > +static inline void memblock_set_bottom_up(bool enable) > +{ > + memblock.bottom_up = enable; > +} > + > +static inline bool memblock_bottom_up(void) > +{ > + return memblock.bottom_up; > +} Can you please explain what this is for here? > + /* > + * we always limit bottom-up allocation above the kernel, > + * but top-down allocation doesn't have the limit, so > + * retrying top-down allocation may succeed when bottom-up > + * allocation failed. > + * > + * bottom-up allocation is expected to be fail very rarely, > + * so we use WARN_ONCE() here to see the stack trace if > + * fail happens. > + */ > + WARN_ONCE(1, "memblock: Failed to allocate memory in bottom up " > + "direction. Now try top down direction.\n"); > + } You and I would know what was going on and what the consequence of the failure may be but the above warning message is kinda useless to a user / admin, right? It doesn't really say anything meaningful. 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