Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754381Ab3CKTfn (ORCPT ); Mon, 11 Mar 2013 15:35:43 -0400 Received: from dcvr.yhbt.net ([64.71.152.64]:57319 "EHLO dcvr.yhbt.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754236Ab3CKTfm (ORCPT ); Mon, 11 Mar 2013 15:35:42 -0400 Date: Mon, 11 Mar 2013 19:35:41 +0000 From: Eric Wong To: Mathieu Desnoyers , Lai Jiangshan Cc: linux-kernel@vger.kernel.org, Davide Libenzi Subject: wfcqueue (in Userspace RCU) for Linux kernel (for epoll) Message-ID: <20130311193541.GA11149@dcvr.yhbt.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 916 Lines: 23 Hi, I'm looking to reduce contention for the ep->lock spin lock in epoll. I came across wfcqueue in Userspace RCU and am wondering if there's any reason (other that lack of developer time/users) it hasn't been adapted for the Linux kernel. I'd be happy to do the work if it's suitable (and omit parts which may not be, such as busy wait). Using a mutex lock (while in process context) for dequeue works for epoll. I mainly want a lock-free enqueue for ep_poll_callback since that may be called in IRQ context. I suppose I can also use the llist LIFO in ep_poll_callback and reverse that while in process context, too... ref: http://git.lttng.org/userspace-rcu.git -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/