From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752243Ab0KDCsy (ORCPT ); Wed, 3 Nov 2010 22:48:54 -0400 Received: from mail-gy0-f174.google.com ([209.85.160.174]:59122 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751001Ab0KDCsu (ORCPT ); Wed, 3 Nov 2010 22:48:50 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:content-transfer-encoding :in-reply-to:user-agent; b=xIPz43VxY2+dRj29JtBpy61YL3KKqtzXmH3gyMUdKs/nvvzjyk06+o0RrL/iAMR6qM UyMqIYMPQFIsaVZex2Jdd3RY5tz9CxXqyoT1ImvudMk/R2hbPM6sGmfBtaE8WjTxe+9p uLNBogCgYWrB3XQs15BKQzG306BziJEioe9Wo= Date: Thu, 4 Nov 2010 10:52:51 +0800 From: =?utf-8?Q?Am=C3=A9rico?= Wang To: Wu Fengguang Cc: Tetsuo Handa , "mrubin@google.com" , "david@fromorbit.com" , "axboe@kernel.dk" , "kosaki.motohiro@jp.fujitsu.com" , "nickpiggin@yahoo.com.au" , "akpm@linux-foundation.org" , "torvalds@linux-foundation.org" , "linux-kernel@vger.kernel.org" Subject: Re: [2.6.37-rc1] /proc/vmstat failure. Message-ID: <20101104025251.GA5210@cr0.nay.redhat.com> References: <201011010053.ADE86905.JMLFHVtSQOOFOF@I-love.SAKURA.ne.jp> <201011032011.BAB21899.OHVQtFLSFJMFOO@I-love.SAKURA.ne.jp> <20101103174643.GA4985@localhost> <201011040654.GDB05271.SOFJFFtOMLHOQV@I-love.SAKURA.ne.jp> <20101104022052.GA7800@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20101104022052.GA7800@localhost> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 04, 2010 at 10:20:52AM +0800, Wu Fengguang wrote: >On Thu, Nov 04, 2010 at 05:54:48AM +0800, Tetsuo Handa wrote: >> Wu Fengguang wrote: >> > On Wed, Nov 03, 2010 at 07:11:11PM +0800, Tetsuo Handa wrote: >> > > Hello. >> > > >> > > "cat /proc/vmstat" triggered below failure. >> > > >> > > BUG: unable to handle kernel paging request at 07c06d16 >> > > IP: [] strnlen+0x6/0x20 >> > >> > It seems that m->private is of type (void *) while the original v is >> > (unsigned long *). Can be fixed by the following patch. >> >> Fixed by this patch. Thank you. > >Great, thanks! > >> By the way, GCC treats "(void *) + offset" as "(char *) + offset" >> but it is GCC specific extention. Maybe we should avoid such usage >> in order to avoid build failure for other compilers. > >"(void *) + offset" seems to be used quite often. > >I tried enable this gcc option, only to see huge amount of warnings. > > -Wpointer-arith > Warn about anything that depends on the "size of" a > function type or of "void". GNU C assigns these types a > size of 1, for convenience in calculations with "void *" > pointers and pointers to functions. > Yup! I think it is good to have this. >/cc/linux-next/scripts/mod/file2alias.c:88: warning: pointer of type ‘void *’ used in arithmetic ... >/cc/linux-next/scripts/mod/modpost.c:1565: warning: pointer of type ‘void *’ used in arithmetic > No problem, this is from kbuild and most of them that I checked are actually fine, we can send patches to remove these warnings.