From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f199.google.com (mail-pg1-f199.google.com [209.85.215.199]) by kanga.kvack.org (Postfix) with ESMTP id B15726B078A for ; Fri, 17 Aug 2018 05:29:30 -0400 (EDT) Received: by mail-pg1-f199.google.com with SMTP id a26-v6so3337341pgw.7 for ; Fri, 17 Aug 2018 02:29:30 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id e6-v6si1756772pgh.50.2018.08.17.02.29.29 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 17 Aug 2018 02:29:29 -0700 (PDT) Date: Fri, 17 Aug 2018 11:29:23 +0200 From: Michal Hocko Subject: Re: [Bug 196157] New: 100+ times slower disk writes on 4.x+/i386/16+RAM, compared to 3.x Message-ID: <20180817092923.GB709@dhcp22.suse.cz> References: <328204943.8183321.1534496501208.ref@mail.yahoo.com> <328204943.8183321.1534496501208@mail.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <328204943.8183321.1534496501208@mail.yahoo.com> Sender: owner-linux-mm@kvack.org List-ID: To: Thierry Cc: Alkis Georgopoulos , Andrew Morton , linux-mm@kvack.org, bugzilla-daemon@bugzilla.kernel.org, Mel Gorman , Johannes Weiner On Fri 17-08-18 09:01:41, Thierry wrote: > Bug still present for 32 bits kernel in v4.18.1, and now, v4.1 (last > working Linux kernel for 32 bits machines with 16Gb or more RAM) has > gone unmaintained... Have you tried to set highmem_is_dirtyable as suggested elsewhere? I would like to stress out that 16GB with 32b kernels doesn't play really nice. Even small changes (larger kernel memory footprint) can lead to all sorts of problems. I would really recommend using 64b kernels instead. There shouldn't be any real reason to stick with 32b highmem based kernel for such a large beast. I strongly doubt the cpu itself would be 32b only. -- Michal Hocko SUSE Labs