From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1947807AbdDYOAr (ORCPT ); Tue, 25 Apr 2017 10:00:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42988 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1947770AbdDYOA2 (ORCPT ); Tue, 25 Apr 2017 10:00:28 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com DFAA3C04BD37 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=mtosatti@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com DFAA3C04BD37 Message-Id: <20170425135717.375295031@redhat.com> User-Agent: quilt/0.60-1 Date: Tue, 25 Apr 2017 10:57:17 -0300 From: Marcelo Tosatti To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Luiz Capitulino , Rik van Riel , Linux RT Users Subject: [patch 0/2] per-CPU vmstat thresholds and vmstat worker disablement X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Tue, 25 Apr 2017 14:00:28 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The per-CPU vmstat worker is a problem on -RT workloads (because ideally the CPU is entirely reserved for the -RT app, without interference). The worker transfers accumulated per-CPU vmstat counters to global counters. To resolve the problem, create two tunables: * Userspace configurable per-CPU vmstat threshold: by default the VM code calculates the size of the per-CPU vmstat arrays. This tunable allows userspace to configure the values. * Userspace configurable per-CPU vmstat worker: allow disabling the per-CPU vmstat worker.