Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751942Ab0HQXj7 (ORCPT ); Tue, 17 Aug 2010 19:39:59 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:40813 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750912Ab0HQXjz (ORCPT ); Tue, 17 Aug 2010 19:39:55 -0400 Date: Tue, 17 Aug 2010 16:40:13 -0700 (PDT) Message-Id: <20100817.164013.193700583.davem@davemloft.net> To: torvalds@linux-foundation.org Cc: tony.luck@intel.com, walken@google.com, dhowells@redhat.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: tasks getting stuck on mmap_sem? From: David Miller In-Reply-To: References: X-Mailer: Mew version 6.3 on Emacs 23.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1001 Lines: 26 From: Linus Torvalds Date: Tue, 17 Aug 2010 14:28:49 -0700 > Oh, and it strikes me when looking at the sparc rwsem-const.h that it > has some unsigned constants in it. I think > > #define RWSEM_WAITING_BIAS 0xffff0000 > > is actually unsigned, because it's a hex constant that doesn't fit in > a signed int. So it's of type 'unsigned int' if I recall the C type > rules right. You were right all along, of course. Nice spotting. Something was messed up with my testing methodology last night such that I didn't test the revert of the lib/rwsem.c changes properly. Those actually did in fact introduce the problem. And fixing these sparc rwsem values to be signed constants fixes the bug. Thanks guys. -- 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/