From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f199.google.com (mail-io0-f199.google.com [209.85.223.199]) by kanga.kvack.org (Postfix) with ESMTP id 190056B02EE for ; Fri, 12 May 2017 12:57:18 -0400 (EDT) Received: by mail-io0-f199.google.com with SMTP id k91so41325887ioi.3 for ; Fri, 12 May 2017 09:57:18 -0700 (PDT) Received: from resqmta-ch2-04v.sys.comcast.net (resqmta-ch2-04v.sys.comcast.net. [2001:558:fe21:29:69:252:207:36]) by mx.google.com with ESMTPS id e193si4085803itc.118.2017.05.12.09.57.17 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 12 May 2017 09:57:17 -0700 (PDT) Date: Fri, 12 May 2017 11:57:15 -0500 (CDT) From: Christoph Lameter Subject: Re: [patch 2/2] MM: allow per-cpu vmstat_threshold and vmstat_worker configuration In-Reply-To: <20170512161915.GA4185@amt.cnet> Message-ID: References: <20170425135717.375295031@redhat.com> <20170425135846.203663532@redhat.com> <20170502102836.4a4d34ba@redhat.com> <20170502165159.GA5457@amt.cnet> <20170502131527.7532fc2e@redhat.com> <20170512122704.GA30528@amt.cnet> <20170512154026.GA3556@amt.cnet> <20170512161915.GA4185@amt.cnet> Content-Type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Marcelo Tosatti Cc: Luiz Capitulino , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Rik van Riel , Linux RT Users , cmetcalf@mellanox.com On Fri, 12 May 2017, Marcelo Tosatti wrote: > > What exactly is the issue you are seeing and want to address? I think we > > have similar aims and as far as I know the current situation is already > > good enough for what you may need. You may just not be aware of how to > > configure this. > > I want to disable vmstat worker thread completly from an isolated CPU. > Because it adds overhead to a latency target, target which > the lower the better. NOHZ already does that. I wanted to know what your problem is that you see. The latency issue has already been solved as far as I can tell . Please tell me why the existing solutions are not sufficient for you. > > I doubt that doing inline updates will do much good compared to what we > > already have and what the dataplan mode can do. > > Can the dataplan mode disable vmstat worker thread completly on a given > CPU? That already occurs when you call quiet_vmstat() and is used by the NOHZ logic. Configure that correctly and you should be fine. -- 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