From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752077AbdFOSsY (ORCPT ); Thu, 15 Jun 2017 14:48:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:49962 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750849AbdFOSsX (ORCPT ); Thu, 15 Jun 2017 14:48:23 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 292A2219A9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=mcgrof@kernel.org From: "Luis R. Rodriguez" To: peterz@infradead.org, paulmck@linux.vnet.ibm.com, oleg@redhat.com, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com Cc: paul.gortmaker@windriver.com, ebiederm@xmission.com, dmitry.torokhov@gmail.com, linux-kernel@vger.kernel.org, "Luis R. Rodriguez" Subject: [RFC v2 0/2] swait: add idle to make idle-hacks on kthreads explicit Date: Thu, 15 Jun 2017 11:48:18 -0700 Message-Id: <20170615184820.22994-1-mcgrof@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <87zid92ns2.fsf@xmission.com> References: <87zid92ns2.fsf@xmission.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org While reviewing RCU's interruptible swaits I noticed signals were actually not expected. Paul explained that the reason signals are not expected is we use kthreads, which don't get signals, furthermore the code avoided the uninterruptible swaits as otherwise it would contribute to the system load average on idle, bumping it from 0 to 2 or 3 (depending on preemption). Since this can be confusing its best to be explicit about the requirements and goals. This patch depends on the other killable swaits [0] recently proposed as well interms of context. Thee patch can however be tested independently if the hunk is addressed separately. [0] https://lkml.kernel.org/r/20170614222017.14653-3-mcgrof@kernel.org Luis R. Rodriguez (2): swait: add idle variants which don't contribute to load average rcu: use idle versions of swait to make idle-hack clear include/linux/swait.h | 25 +++++++++++++++++++++++++ kernel/rcu/tree.c | 4 ++-- 2 files changed, 27 insertions(+), 2 deletions(-) -- 2.11.0