Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760039AbcDMPDf (ORCPT ); Wed, 13 Apr 2016 11:03:35 -0400 Received: from resqmta-ch2-12v.sys.comcast.net ([69.252.207.44]:42912 "EHLO resqmta-ch2-12v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756942AbcDMPDd (ORCPT ); Wed, 13 Apr 2016 11:03:33 -0400 Date: Wed, 13 Apr 2016 10:03:30 -0500 (CDT) From: Christoph Lameter X-X-Sender: cl@east.gentwo.org To: Waiman Long cc: Alexander Viro , Jan Kara , Jeff Layton , "J. Bruce Fields" , Tejun Heo , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Ingo Molnar , Peter Zijlstra , Andi Kleen , Dave Chinner , Boqun Feng , Scott J Norton , Douglas Hatch Subject: Re: [PATCH v7 1/4] lib/percpu-list: Per-cpu list with associated per-cpu locks In-Reply-To: <1460501686-37096-2-git-send-email-Waiman.Long@hpe.com> Message-ID: References: <1460501686-37096-1-git-send-email-Waiman.Long@hpe.com> <1460501686-37096-2-git-send-email-Waiman.Long@hpe.com> Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 643 Lines: 13 On Tue, 12 Apr 2016, Waiman Long wrote: > List entry insertion is strictly per cpu. List deletion, however, can > happen in a cpu other than the one that did the insertion. So we still > need lock to protect the list. Because of that, there may still be > a small amount of contention when deletion is being done. Ok then the list is not per cpu anymore. Can we call this something else please to avoid confusion? Spinlocks in per cpu structures are a bit confusing otherwise. Seems that there is no requirement that the list can only be accessed from a single cpu so its not per cpu per se anymore. Maybe lock-list instead of percpu-list?