Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756103AbaAHLub (ORCPT ); Wed, 8 Jan 2014 06:50:31 -0500 Received: from e28smtp09.in.ibm.com ([122.248.162.9]:50851 "EHLO e28smtp09.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754960AbaAHLu2 (ORCPT ); Wed, 8 Jan 2014 06:50:28 -0500 Message-ID: <52CD3D36.1010706@linux.vnet.ibm.com> Date: Wed, 08 Jan 2014 17:27:42 +0530 From: Raghavendra K T Organization: IBM User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Jan Kara CC: Andrew Morton , Fengguang Wu , David Cohen , Al Viro , Damien Ramonda , Linus , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH V3] mm readahead: Fix the readahead fail in case of empty numa node References: <1389003715-29733-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com> <20140106141300.4e1c950d45c614d6c29bdd8f@linux-foundation.org> <52CD1113.2070003@linux.vnet.ibm.com> <20140108104713.GB8256@quack.suse.cz> In-Reply-To: <20140108104713.GB8256@quack.suse.cz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14010811-2674-0000-0000-00000C327F05 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/08/2014 04:17 PM, Jan Kara wrote: > On Wed 08-01-14 14:19:23, Raghavendra K T wrote: >> On 01/07/2014 03:43 AM, Andrew Morton wrote: >>> On Mon, 6 Jan 2014 15:51:55 +0530 Raghavendra K T wrote: [...] >> But having said that I am not able to get an idea of sane implementation >> to solve this readahead failure bug overcoming the anomaly you pointed >> :(. hints/ideas.. ?? please let me know. > So if we would be happy with just fixing corner cases like this, we might > use total node memory size to detect them, can't we? If total node memory > size is 0, we can use 16 MB (or global number of free pages / 2 if we would > be uneasy with fixed 16 MB limit) as an upperbound... > Thanks Honza. This seems to be more sensible option, I 'll send the patch with that change (including 16MB limit if nobody disagrees). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/