From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762814AbXGaO0S (ORCPT ); Tue, 31 Jul 2007 10:26:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757475AbXGaO0D (ORCPT ); Tue, 31 Jul 2007 10:26:03 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:34228 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752309AbXGaO0B (ORCPT ); Tue, 31 Jul 2007 10:26:01 -0400 Subject: Re: [PATCH 0/2][RFC] VFCIPI v3 From: Peter Zijlstra To: Gregory Haskins Cc: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org, Ingo Molnar In-Reply-To: <20070731132153.4790.37217.stgit@novell1.haskins.net> References: <20070731132153.4790.37217.stgit@novell1.haskins.net> Content-Type: text/plain Date: Tue, 31 Jul 2007 16:25:57 +0200 Message-Id: <1185891957.12034.12.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi Gregory, This patch set approaches the problem from the wrong angle (and has a few problems due to that). The idea to use a workqueue (or in your case workqueue-like) solution to the problem is valid, however instead of re-using (and improving) the current workqueue infrastructure, you re-implement it (with mistakes). The solution currently in -rt uses regular workqueues to implement schedule_on_each_cpu() - a drop in replacement for on_each_cpu() in the context of -rt and useful outside of that if people do require such functionality. Your idea of using priority arrays in the workqueue is a good one, please implement that for the regular workqueues. Your idea that GFP_ATOMIC is broken in -rt is unfortunate, it isn't. The whole allocator is preemptable - that is a feature! Please keep up the good work, looking forward to those prio-workqueue patches. Peter