From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-f200.google.com (mail-qk1-f200.google.com [209.85.222.200]) by kanga.kvack.org (Postfix) with ESMTP id 5E8C56B59C7 for ; Fri, 30 Nov 2018 14:18:24 -0500 (EST) Received: by mail-qk1-f200.google.com with SMTP id v74so6237878qkb.21 for ; Fri, 30 Nov 2018 11:18:24 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id 2sor6198128qvr.12.2018.11.30.11.18.23 for (Google Transport Security); Fri, 30 Nov 2018 11:18:23 -0800 (PST) Date: Fri, 30 Nov 2018 11:18:19 -0800 From: Tejun Heo Subject: Re: [RFC PATCH v4 00/13] ktask: multithread CPU-intensive kernel work Message-ID: <20181130191819.GJ2509588@devbig004.ftw2.facebook.com> References: <20181105165558.11698-1-daniel.m.jordan@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181105165558.11698-1-daniel.m.jordan@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: Daniel Jordan Cc: linux-mm@kvack.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, aarcange@redhat.com, aaron.lu@intel.com, akpm@linux-foundation.org, alex.williamson@redhat.com, bsd@redhat.com, darrick.wong@oracle.com, dave.hansen@linux.intel.com, jgg@mellanox.com, jwadams@google.com, jiangshanlai@gmail.com, mhocko@kernel.org, mike.kravetz@oracle.com, Pavel.Tatashin@microsoft.com, prasad.singamsetty@oracle.com, rdunlap@infradead.org, steven.sistare@oracle.com, tim.c.chen@intel.com, vbabka@suse.cz Hello, On Mon, Nov 05, 2018 at 11:55:45AM -0500, Daniel Jordan wrote: > Michal, you mentioned that ktask should be sensitive to CPU utilization[1]. > ktask threads now run at the lowest priority on the system to avoid disturbing > busy CPUs (more details in patches 4 and 5). Does this address your concern? > The plan to address your other comments is explained below. Have you tested what kind of impact this has on bandwidth of a system in addition to latency? The thing is while this would make a better use of a system which has idle capacity, it does so by doing more total work. It'd be really interesting to see how this affects bandwidth of a system too. Thanks. -- tejun