Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751926Ab0AJCJ6 (ORCPT ); Sat, 9 Jan 2010 21:09:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751346Ab0AJCJ6 (ORCPT ); Sat, 9 Jan 2010 21:09:58 -0500 Received: from one.firstfloor.org ([213.235.205.2]:37870 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751301Ab0AJCJ5 (ORCPT ); Sat, 9 Jan 2010 21:09:57 -0500 Date: Sun, 10 Jan 2010 03:09:55 +0100 From: Andi Kleen To: linux-kernel@vger.kernel.org Subject: 2.6.33 pagemap endless read loop Message-ID: <20100110020955.GB25323@basil.fritz.box> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1582 Lines: 39 An LTP run on x86-64/2.6.33-rc3 run right now results in "proc01" hanging lr-x------ 1 root root 64 2010-01-10 02:28 7 -> /proc/2679/task/2679/pagemap strace shows an endless loop of read(7, "\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0"..., 1024) = 1024 read(7, "\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0"..., 1024) = 1024 read(7, "\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0"..., 1024) = 1024 read(7, "\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0"..., 1024) = 1024 read(7, "\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0"..., 1024) = 1024 read(7, "\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0"..., 1024) = 1024 read(7, "\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0\0\0\0\0\6\0\0\0"..., 1024) = 10 cat of that file hangs in the same way so it seems like a kernel bug. A cat of /proc/2679/pagemap also hangs, in fact any pagemap cat seems to. I tried to revert the latest change from Horiguchi-san: commit 5dc37642cbce34619e4588a9f0bdad1d2f870956 Author: Naoya Horiguchi Date: Mon Dec 14 18:00:01 2009 -0800 mm hugetlb: add hugepage support to pagemap but that didn't fix it, so it must be something else. Haven't done further bisect or anything, should be easy to reproduce. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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/