From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752689Ab2K2TLd (ORCPT ); Thu, 29 Nov 2012 14:11:33 -0500 Received: from mga09.intel.com ([134.134.136.24]:24113 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751003Ab2K2TLc (ORCPT ); Thu, 29 Nov 2012 14:11:32 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,186,1355126400"; d="scan'208";a="226786996" From: Andi Kleen To: Prasad Koya Cc: dzickus@redhat.com, aarcange@redhat.com, LKML Subject: Re: vmalloc_sync_all(), 64bit kernel, patches 9c48f1c629ecfa114850c03f875c6691003214de, a79e53d85683c6dd9f99c90511028adc2043031f References: Date: Thu, 29 Nov 2012 11:11:28 -0800 In-Reply-To: (Prasad Koya's message of "Mon, 26 Nov 2012 15:06:53 -0800") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Prasad Koya writes: > Hi > > Before going into crashkernel, nmi_shootdown_cpus() calls > register_die_notifier(), which calls vmalloc_sync_all(). I'm seeing > lockup in sync_global_pgds() (init_64.c). From 3.2 and up, > register_die_notifier() is replaced with register_nmi_handler() (patch > 9c48f1c629ecfa114850c03f875c6691003214de), which doesn't call > vmalloc_sync_all(). Is it ok to skip vmalloc_sync_all() in this path? Yes it's ok for this case. vmalloc_sync_all is only needed when the notifier is in freshly loaded module code. -Andi -- ak@linux.intel.com -- Speaking for myself only