From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id 636B86B0033 for ; Wed, 27 Dec 2017 18:34:53 -0500 (EST) Received: by mail-pg0-f72.google.com with SMTP id e12so2683547pga.5 for ; Wed, 27 Dec 2017 15:34:53 -0800 (PST) Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com. [66.63.167.143]) by mx.google.com with ESMTPS id s189si23112165pgb.104.2017.12.27.15.34.52 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 27 Dec 2017 15:34:52 -0800 (PST) Message-ID: <1514417689.3083.1.camel@HansenPartnership.com> Subject: Re: Hang with v4.15-rc trying to swap back in From: James Bottomley Date: Wed, 27 Dec 2017 15:34:49 -0800 In-Reply-To: <20171227232650.GA9702@bbox> References: <1514398340.3986.10.camel@HansenPartnership.com> <1514407817.4169.4.camel@HansenPartnership.com> <20171227232650.GA9702@bbox> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Linux Memory Management List , Andrew Morton On Thu, 2017-12-28 at 08:26 +0900, Minchan Kim wrote: > Hello James, > > On Wed, Dec 27, 2017 at 12:50:17PM -0800, James Bottomley wrote: > > > > Reverting these three patches fixes the problem: > > > > commit aa8d22a11da933dbf880b4933b58931f4aefe91c > > Author: Minchan Kim > > Date:A A A Wed Nov 15 17:33:11 2017 -0800 > > > > A A A A mm: swap: SWP_SYNCHRONOUS_IO: skip swapcache only if swapped > > page > > has no other reference > > > > commit 0bcac06f27d7528591c27ac2b093ccd71c5d0168 > > Author: Minchan Kim > > Date:A A A Wed Nov 15 17:33:07 2017 -0800 > > > > A A A A mm, swap: skip swapcache for swapin of synchronous device > > > > Also need to revert: > > > > commit e9a6effa500526e2a19d5ad042cb758b55b1ef93 > > Author: Huang Ying > > Date:A A A Wed Nov 15 17:33:15 2017 -0800 > > > > A A A A mm, swap: fix false error message in __swp_swapcount() > > > > (The latter is simply because it used a function that is eliminated > > by > > one of the other reversions). A They came into the merge window via > > the > > -mm tree as part of a 4 part series: > > > > Subject: [PATCH v2 0/4] skip swapcache for super fast device > > Message-Id: <1505886205-9671-1-git-send-email-minchan@kernel > > .org > > > > > > > > > > James > > Thanks for the report. > Patches are related to synchronous swap devices like brd, zram, > nvdimm so > > 1. What swap device do you use among them? I've reproduced on nvme and sata spinning rust. > 2. Could you tell me how you can reproduce it? The way to reproduce is to force something to swap and then get it to try to touch the page again. A I do this on my systems by using a large virtual machine, as I said in the email. A There isn't really any definitive reproduction method beyond that. James -- 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