Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751361Ab1BCFU4 (ORCPT ); Thu, 3 Feb 2011 00:20:56 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:45226 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750899Ab1BCFU4 (ORCPT ); Thu, 3 Feb 2011 00:20:56 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: KOSAKI Motohiro Subject: Re: Query about kdump_msg hook into crash_kexec() Cc: kosaki.motohiro@jp.fujitsu.com, Vivek Goyal , "Eric W. Biederman" , linux kernel mailing list , Jarod Wilson In-Reply-To: <20110203121302.93B9.A69D9226@jp.fujitsu.com> References: <20110203020528.GA21603@redhat.com> <20110203121302.93B9.A69D9226@jp.fujitsu.com> Message-Id: <20110203141850.93C2.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Thu, 3 Feb 2011 14:20:53 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1745 Lines: 39 > AFAIK, kexec is used sneak rebooting way when the system face unexpected > scenario on some devices. (Some embedded is running very long time, then > it can't avoid memory bit corruption. all of reset is a last resort. > and a vendor gather logs at periodically checkback). > > The main purpose of to introduce KMSG_DUMP_KEXEC is to be separate it > from KMSG_DUMP_PANIC. At kmsg_dump() initial patch, KMSG_DUMP_PANIC > is always called both kdump is configured or not. But it's no good idea > the same log is to be appeared when both kexec was successed and failured. > Moreover someone don't want any log at kexec phase. They only want logs > when real panic (ie kexec failure) route. Then, I've separated it to two. > Two separated argument can solve above both requreiment. A bit additional explanation, An original patch have kmsg_dump(KMSG_DUMP_PANIC) callsite at following point. I didn't think it makes either embedded or kdump folks happiness. Thus I moved it after crash_kexec(). --------------------------------------------------------------------- @@ -74,6 +75,7 @@ NORET_TYPE void panic(const char * fmt, ...) dump_stack(); #endif + kmsg_dump(KMSG_DUMP_PANIC); /* * If we have crashed and we have a crash kernel loaded let it handle * everything else. * Do we want to call this before we try to display a message? */ crash_kexec(NULL); --------------------------------------------------------------------- -- 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/