From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: Re: [PATCH] ACPI/osl: speedup grace period in acpi_os_map_cleanup Date: Sat, 8 Nov 2014 16:51:24 -0800 Message-ID: <20141109005124.GG4901@linux.vnet.ibm.com> References: <20141108094717.9388.34638.stgit@zurg> <20141108221347.GF4901@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from e39.co.us.ibm.com ([32.97.110.160]:47275 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752814AbaKIAvv (ORCPT ); Sat, 8 Nov 2014 19:51:51 -0500 Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sat, 8 Nov 2014 17:51:51 -0700 Content-Disposition: inline In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Alexander Monakov Cc: Konstantin Khlebnikov , linux-acpi@vger.kernel.org, "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Len Brown , Tom Boshoven , x86@kernel.org, Josh Triplett On Sun, Nov 09, 2014 at 03:24:34AM +0400, Alexander Monakov wrote: > On Sun, Nov 9, 2014 at 1:13 AM, Paul E. McKenney > wrote: > > > > Did anyone try replacing the synchronize_rcu() with > > synchronize_rcu_expedited()? That should provide substantial speedups > > over synchronize_rcu(). > > I've just briefly tested it on my laptop, and it also helps to avoid the issue. OK, good. In the past, synchronize_rcu_expedited() has been a bit unfriendly to battery-powered platforms and to real-time and HPC workloads, but recent changes for the most part fix this. Thanx, Paul