From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754904AbeASI2s (ORCPT ); Fri, 19 Jan 2018 03:28:48 -0500 Received: from mail-pg0-f68.google.com ([74.125.83.68]:36631 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751282AbeASI2l (ORCPT ); Fri, 19 Jan 2018 03:28:41 -0500 X-Google-Smtp-Source: AH8x226gG8oFXH/S1zf8QfvsXbDJsZV4Hg7VnN1/OP7FwC11m4jIRJnj1k1ubi0Vd2JKgvjfEWGuVA== Date: Fri, 19 Jan 2018 17:28:35 +0900 From: Sergey Senozhatsky To: Dave Young Cc: Sergey Senozhatsky , Andi Kleen , pmladek@suse.com, sergey.senozhatsky@gmail.com, rostedt@goodmis.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, kexec@lists.infradead.org Subject: Re: [PATCH] print kdump kernel loaded status in stack dump Message-ID: <20180119082835.GA477@jagdpanzerIV> References: <20180117045057.GA4994@dhcp-128-65.nay.redhat.com> <878tcvt592.fsf@linux.intel.com> <20180119054538.GA484@jagdpanzerIV> <20180119081628.GB3985@dhcp-128-65.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180119081628.GB3985@dhcp-128-65.nay.redhat.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (01/19/18 16:16), Dave Young wrote: > On 01/19/18 at 02:45pm, Sergey Senozhatsky wrote: > > On (01/18/18 10:02), Andi Kleen wrote: > > > Dave Young writes: > > > > printk("%sHardware name: %s\n", > > > > log_lvl, dump_stack_arch_desc_str); > > > > + if (kexec_crash_loaded()) > > > > + printk("%skdump kernel loaded\n", log_lvl); > > > > > > Oops/warnings are getting longer and longer, often scrolling away > > > from the screen, and if the kernel crashes backscroll does not work > > > anymore, so precious information is lost. > > > > true. I even ended up having a console_reflush_on_panic() function. it > > simply re-prints with a delay [so I can at least read the oops] logbuf > > entries every once in a while, staring with the first oops_in_progress > > record. > > > > If too many messages printed on screen, then the next flush will > still scroll up. right. but it re-prints Oops with a new console_unlock_delay() delay which gives me enough time to either read it as many times as I want, or take a picture, etc. it's not as fast as the normal oops print out. [I'm not entirely sure I see why do we have printk_delay() in vprintk_emit()... I mean I probably can see some reasoning behind it, but at the same it makes sense to slow down console_unlock() as well] -ss From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pg0-x244.google.com ([2607:f8b0:400e:c05::244]) by bombadil.infradead.org with esmtps (Exim 4.89 #1 (Red Hat Linux)) id 1ecS2d-0007fe-Fr for kexec@lists.infradead.org; Fri, 19 Jan 2018 08:28:52 +0000 Received: by mail-pg0-x244.google.com with SMTP id c194so890692pga.12 for ; Fri, 19 Jan 2018 00:28:41 -0800 (PST) Date: Fri, 19 Jan 2018 17:28:35 +0900 From: Sergey Senozhatsky Subject: Re: [PATCH] print kdump kernel loaded status in stack dump Message-ID: <20180119082835.GA477@jagdpanzerIV> References: <20180117045057.GA4994@dhcp-128-65.nay.redhat.com> <878tcvt592.fsf@linux.intel.com> <20180119054538.GA484@jagdpanzerIV> <20180119081628.GB3985@dhcp-128-65.nay.redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180119081628.GB3985@dhcp-128-65.nay.redhat.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Dave Young Cc: pmladek@suse.com, Andi Kleen , Sergey Senozhatsky , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, sergey.senozhatsky@gmail.com, akpm@linux-foundation.org On (01/19/18 16:16), Dave Young wrote: > On 01/19/18 at 02:45pm, Sergey Senozhatsky wrote: > > On (01/18/18 10:02), Andi Kleen wrote: > > > Dave Young writes: > > > > printk("%sHardware name: %s\n", > > > > log_lvl, dump_stack_arch_desc_str); > > > > + if (kexec_crash_loaded()) > > > > + printk("%skdump kernel loaded\n", log_lvl); > > > > > > Oops/warnings are getting longer and longer, often scrolling away > > > from the screen, and if the kernel crashes backscroll does not work > > > anymore, so precious information is lost. > > > > true. I even ended up having a console_reflush_on_panic() function. it > > simply re-prints with a delay [so I can at least read the oops] logbuf > > entries every once in a while, staring with the first oops_in_progress > > record. > > > > If too many messages printed on screen, then the next flush will > still scroll up. right. but it re-prints Oops with a new console_unlock_delay() delay which gives me enough time to either read it as many times as I want, or take a picture, etc. it's not as fast as the normal oops print out. [I'm not entirely sure I see why do we have printk_delay() in vprintk_emit()... I mean I probably can see some reasoning behind it, but at the same it makes sense to slow down console_unlock() as well] -ss _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec