From mboxrd@z Thu Jan 1 00:00:00 1970 From: peterz@infradead.org (Peter Zijlstra) Date: Sat, 7 Apr 2018 11:07:54 +0200 Subject: [PATCH 02/10] locking/qspinlock: Remove unbounded cmpxchg loop from locking slowpath In-Reply-To: References: <1522947547-24081-1-git-send-email-will.deacon@arm.com> <1522947547-24081-3-git-send-email-will.deacon@arm.com> Message-ID: <20180407090754.GP4082@hirez.programming.kicks-ass.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Apr 06, 2018 at 04:50:19PM -0400, Waiman Long wrote: > # of threads 4.16 kernel patched 4.16 kernel > ------------ ----------- ------------------- > 1 7,417 kop/s 7,408 kop/s > 2 5,755 kop/s 4,486 kop/s > 3 4,214 kop/s 4,169 kop/s > 4 4,396 kop/s 4,383 kop/s > Interesting, I didn't see that dip in my userspace tests.. I'll have to try again. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751320AbeDGJIJ (ORCPT ); Sat, 7 Apr 2018 05:08:09 -0400 Received: from merlin.infradead.org ([205.233.59.134]:42620 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751069AbeDGJII (ORCPT ); Sat, 7 Apr 2018 05:08:08 -0400 Date: Sat, 7 Apr 2018 11:07:54 +0200 From: Peter Zijlstra To: Waiman Long Cc: Will Deacon , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, mingo@kernel.org, boqun.feng@gmail.com, paulmck@linux.vnet.ibm.com, catalin.marinas@arm.com Subject: Re: [PATCH 02/10] locking/qspinlock: Remove unbounded cmpxchg loop from locking slowpath Message-ID: <20180407090754.GP4082@hirez.programming.kicks-ass.net> References: <1522947547-24081-1-git-send-email-will.deacon@arm.com> <1522947547-24081-3-git-send-email-will.deacon@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.3 (2018-01-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 06, 2018 at 04:50:19PM -0400, Waiman Long wrote: > # of threads 4.16 kernel patched 4.16 kernel > ------------ ----------- ------------------- > 1 7,417 kop/s 7,408 kop/s > 2 5,755 kop/s 4,486 kop/s > 3 4,214 kop/s 4,169 kop/s > 4 4,396 kop/s 4,383 kop/s > Interesting, I didn't see that dip in my userspace tests.. I'll have to try again.