From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.nokia.com ([192.100.122.230] helo=mgw-mx03.nokia.com) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1MxJ2R-0002Hv-29 for linux-mtd@lists.infradead.org; Mon, 12 Oct 2009 11:26:07 +0000 Subject: Re: [PATCH] panic.c: export panic_on_oops From: Artem Bityutskiy To: Ingo Molnar In-Reply-To: <20091012111545.GB8857@elte.hu> References: <1255241458-11665-1-git-send-email-dedekind1@gmail.com> <20091012111545.GB8857@elte.hu> Content-Type: text/plain; charset="UTF-8" Date: Mon, 12 Oct 2009 14:25:31 +0300 Message-Id: <1255346731.9659.31.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: LKML , "Koskinen Aaro \(Nokia-D/Helsinki\)" , linux-mtd , Simon Kagstrom , Andrew Morton , David Woodhouse Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2009-10-12 at 13:15 +0200, ext Ingo Molnar wrote: > > We use the mtdoops module which stores oopses on the Flash partition, > > in order to make it possible to analyze them later. And mtdoops needs > > to know whether 'panic_on_oops' is on or off. Thus, we need this > > variable to be exported. > > hm, why does it need it? Could you send the patch please that makes use > of it (as an easy way to explain the need for the export) - current > upstream drivers/mtd/mtdoops.c doesnt need it so it must be some pending > change. Yes, current drivers/mtd/mtdoops.c does not need it, but we have this patch: http://lists.infradead.org/pipermail/linux-mtd/2009-October/027450.html which makes sure mtdoops writes the oops log immediately, because we have 'panic_on_oops' set so this is our last chance to save the oops. Here is the patch inlined as well: Author: Aaro Koskinen Date: Thu Oct 1 18:16:55 2009 +0300 mtd: mtdoops: do not schedule work if we are going to die If panic_on_oops is set, the log should be written right away because this is not going to be a second chance. Signed-off-by: Aaro Koskinen Signed-off-by: Artem Bityutskiy diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c index 1060337..ac67833 100644 --- a/drivers/mtd/mtdoops.c +++ b/drivers/mtd/mtdoops.c @@ -335,7 +335,7 @@ static void mtdoops_console_sync(void) cxt->ready = 0; spin_unlock_irqrestore(&cxt->writecount_lock, flags); - if (mtd->panic_write && in_interrupt()) + if (mtd->panic_write && (in_interrupt() || panic_on_oops)) /* Interrupt context, we're going to panic so try and log */ mtdoops_write(cxt, 1); else -- Best Regards, Artem Bityutskiy (Артём Битюцкий) From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756286AbZJLL1d (ORCPT ); Mon, 12 Oct 2009 07:27:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754786AbZJLL1c (ORCPT ); Mon, 12 Oct 2009 07:27:32 -0400 Received: from smtp.nokia.com ([192.100.122.230]:21707 "EHLO mgw-mx03.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754560AbZJLL1b (ORCPT ); Mon, 12 Oct 2009 07:27:31 -0400 Subject: Re: [PATCH] panic.c: export panic_on_oops From: Artem Bityutskiy Reply-To: dedekind1@gmail.com To: Ingo Molnar Cc: Andrew Morton , "Koskinen Aaro (Nokia-D/Helsinki)" , David Woodhouse , Simon Kagstrom , linux-mtd , LKML In-Reply-To: <20091012111545.GB8857@elte.hu> References: <1255241458-11665-1-git-send-email-dedekind1@gmail.com> <20091012111545.GB8857@elte.hu> Content-Type: text/plain; charset="UTF-8" Date: Mon, 12 Oct 2009 14:25:31 +0300 Message-Id: <1255346731.9659.31.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.26.3 (2.26.3-1.fc11) Content-Transfer-Encoding: 8bit X-OriginalArrivalTime: 12 Oct 2009 11:25:33.0080 (UTC) FILETIME=[B6322980:01CA4B2E] X-Nokia-AV: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2009-10-12 at 13:15 +0200, ext Ingo Molnar wrote: > > We use the mtdoops module which stores oopses on the Flash partition, > > in order to make it possible to analyze them later. And mtdoops needs > > to know whether 'panic_on_oops' is on or off. Thus, we need this > > variable to be exported. > > hm, why does it need it? Could you send the patch please that makes use > of it (as an easy way to explain the need for the export) - current > upstream drivers/mtd/mtdoops.c doesnt need it so it must be some pending > change. Yes, current drivers/mtd/mtdoops.c does not need it, but we have this patch: http://lists.infradead.org/pipermail/linux-mtd/2009-October/027450.html which makes sure mtdoops writes the oops log immediately, because we have 'panic_on_oops' set so this is our last chance to save the oops. Here is the patch inlined as well: Author: Aaro Koskinen Date: Thu Oct 1 18:16:55 2009 +0300 mtd: mtdoops: do not schedule work if we are going to die If panic_on_oops is set, the log should be written right away because this is not going to be a second chance. Signed-off-by: Aaro Koskinen Signed-off-by: Artem Bityutskiy diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c index 1060337..ac67833 100644 --- a/drivers/mtd/mtdoops.c +++ b/drivers/mtd/mtdoops.c @@ -335,7 +335,7 @@ static void mtdoops_console_sync(void) cxt->ready = 0; spin_unlock_irqrestore(&cxt->writecount_lock, flags); - if (mtd->panic_write && in_interrupt()) + if (mtd->panic_write && (in_interrupt() || panic_on_oops)) /* Interrupt context, we're going to panic so try and log */ mtdoops_write(cxt, 1); else -- Best Regards, Artem Bityutskiy (Артём Битюцкий)