From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751816AbbINVlJ (ORCPT ); Mon, 14 Sep 2015 17:41:09 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:48670 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751170AbbINVlH (ORCPT ); Mon, 14 Sep 2015 17:41:07 -0400 Date: Mon, 14 Sep 2015 14:41:06 -0700 From: Andrew Morton To: Ebru Akagunduz Cc: linux-mm@kvack.org, kirill.shutemov@linux.intel.com, n-horiguchi@ah.jp.nec.com, aarcange@redhat.com, riel@redhat.com, iamjoonsoo.kim@lge.com, xiexiuqi@huawei.com, gorcunov@openvz.org, linux-kernel@vger.kernel.org, mgorman@suse.de, rientjes@google.com, vbabka@suse.cz, aneesh.kumar@linux.vnet.ibm.com, hughd@google.com, hannes@cmpxchg.org, mhocko@suse.cz, boaz@plexistor.com, raindel@mellanox.com Subject: Re: [RFC v5 0/3] mm: make swapin readahead to gain more thp performance Message-Id: <20150914144106.ee205c3ae3f4ec0e5202c9fe@linux-foundation.org> In-Reply-To: <1442259105-4420-1-git-send-email-ebru.akagunduz@gmail.com> References: <1442259105-4420-1-git-send-email-ebru.akagunduz@gmail.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 14 Sep 2015 22:31:42 +0300 Ebru Akagunduz wrote: > This patch series makes swapin readahead up to a > certain number to gain more thp performance and adds > tracepoint for khugepaged_scan_pmd, collapse_huge_page, > __collapse_huge_page_isolate. I'll merge this series for testing. Hopefully Andrea and/or Hugh will find time for a quality think about the issue before 4.3 comes around. It would be much better if we didn't have that sysfs knob - make the control automatic in some fashion. If we can't think of a way of doing that then at least let's document max_ptes_swap very carefully. Explain to our users what it does, why they should care about it, how they should set about determining (ie: measuring) its effect upon their workloads.