From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wj0-f200.google.com (mail-wj0-f200.google.com [209.85.210.200]) by kanga.kvack.org (Postfix) with ESMTP id A5C706B0038 for ; Mon, 9 Jan 2017 03:58:37 -0500 (EST) Received: by mail-wj0-f200.google.com with SMTP id dh1so71419454wjb.0 for ; Mon, 09 Jan 2017 00:58:37 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id c29si7719842wrc.303.2017.01.09.00.58.36 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 09 Jan 2017 00:58:36 -0800 (PST) Date: Mon, 9 Jan 2017 09:58:34 +0100 From: Michal Hocko Subject: Re: hugetlb: reservation race leading to under provisioning Message-ID: <20170109085834.GC7495@dhcp22.suse.cz> References: <20170105151540.GT21618@dhcp22.suse.cz> <20170106085808.GE5556@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Paul Cassella Cc: Mike Kravetz , Naoya Horiguchi , linux-mm@kvack.org On Fri 06-01-17 13:57:59, Paul Cassella wrote: > On Fri, 6 Jan 2017, Michal Hocko wrote: > > On Thu 05-01-17 16:48:03, Mike Kravetz wrote: > > > On 01/05/2017 07:15 AM, Michal Hocko wrote: > > > > > we have a customer report on an older kernel (3.12) but I believe the > > > > same issue is present in the current vanilla kernel. There is a race > > > > between mmap trying to do a reservation which fails when racing with > > > > truncate_hugepages. See the reproduced attached. > > > > > > > > It should go like this (analysis come from the customer and I hope I > > > > haven't screwed their write up). > > Hi Michal, > > There may have been a step missing from what was sent to you, right at the > point Mike asked about. I've added it below. No, I guess the info I got from you was complete. I was trying to reduce the info to the minimum and wasn't explicit about this fact enough assuming it would be clear from the test case which I forgot to add... Sorry about that! -- Michal Hocko SUSE Labs -- 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