From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932682AbYAaN5q (ORCPT ); Thu, 31 Jan 2008 08:57:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933927AbYAaNzi (ORCPT ); Thu, 31 Jan 2008 08:55:38 -0500 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:59463 "EHLO ecfrec.frec.bull.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933676AbYAaNze (ORCPT ); Thu, 31 Jan 2008 08:55:34 -0500 Message-Id: <20080131135356.242752000@bull.net> References: <20080131134018.273154000@bull.net> User-Agent: quilt/0.45-1 Date: Thu, 31 Jan 2008 14:40:23 +0100 From: Nadia.Derbey@bull.net To: linux-kernel@vger.kernel.org, y-goto@jp.fujitsu.com, akpm@linux-foundation.org Cc: linux-mm@kvack.org, containers@lists.linux-foundation.org, matthltc@us.ibm.com, Nadia Derbey Subject: [RFC][PATCH v2 5/7] Invoke the ipcns notifier chain as a work item Content-Disposition: inline; filename=ipc_ipcns_notification_workqueue.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [PATCH 05/07] This patche makes the memory hotplug chain's mutex held for a shorter time: when memory is offlined or onlined a work item is added to the global workqueue. When the work item is run, it notifies the ipcns notifier chain with the IPCNS_MEMCHANGED event. Signed-off-by: Nadia Derbey --- ipc/util.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) Index: linux-2.6.24/ipc/util.c =================================================================== --- linux-2.6.24.orig/ipc/util.c 2008-01-31 11:04:51.000000000 +0100 +++ linux-2.6.24/ipc/util.c 2008-01-31 11:41:01.000000000 +0100 @@ -57,6 +57,14 @@ atomic_t nr_ipc_ns = ATOMIC_INIT(1); #ifdef CONFIG_MEMORY_HOTPLUG +static void ipc_memory_notifier(struct work_struct *work) +{ + ipcns_notify(IPCNS_MEMCHANGED); +} + +static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier); + + static int ipc_memory_callback(struct notifier_block *self, unsigned long action, void *arg) { @@ -65,9 +73,14 @@ static int ipc_memory_callback(struct no case MEM_OFFLINE: /* or offline: it's time to recompute msgmni */ /* * This is done by invoking the ipcns notifier chain with the - * IPC_MEMCHANGED event + * IPC_MEMCHANGED event. + * In order not to keep the lock on the hotplug memory chain + * for too long, queue a work item that will, when waken up, + * activate the ipcns notification chain. + * No need to keep several ipc work items on the queue. */ - ipcns_notify(IPCNS_MEMCHANGED); + if (!work_pending(&ipc_memory_wq)) + schedule_work(&ipc_memory_wq); break; case MEM_GOING_ONLINE: case MEM_GOING_OFFLINE: --