From mboxrd@z Thu Jan 1 00:00:00 1970 From: Petr Mladek Subject: Re: [PATCH 21/30] panic: Introduce the panic pre-reboot notifier list Date: Mon, 16 May 2022 16:33:41 +0200 Message-ID: References: <20220427224924.592546-1-gpiccoli@igalia.com> <20220427224924.592546-22-gpiccoli@igalia.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1652711621; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=fVjlG4/dfH2RJ8QOIc+qrGCmgCcjOpZB+KPjtLQbhUo=; b=g7zXCdiW66+ZORh6/+b42qlwXs71YIm78eBo2DkB+6yci0VblhfjN32vYqq5tvyFP+a35V 4IQbZk+eZ8m4N7dIzfRZvRcjGflhdk2pzgpwxTPHHTNBIE+W9GZV3Zj3ggNIRkQibkb0ZX yDFspItfCnZ03JfIlqNkkDR8LZU/GbA= Content-Disposition: inline In-Reply-To: <20220427224924.592546-22-gpiccoli-wEGTBA9jqPzQT0dZR+AlfA@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Guilherme G. Piccoli" Cc: akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, bcm-kernel-feedback-list-dY08KVG/lbpWk0Htik3J/w@public.gmane.org, coresight-cunTk1MwBs8s++Sfvej+rw@public.gmane.org, linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-alpha-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-edac-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-hyperv-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-leds-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mips-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-parisc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-remoteproc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-s390-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-um-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-xtensa-PjhNF2WwrV/0Sa2dR60CXw@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, openipmi-developer-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, rcu-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, sparclinux-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, xen-devel-GuqFBffKawtpuQazS67q72D2FQJk+8+b@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, kernel-dev-wEGTBA9jqPzQT0dZR+AlfA@public.gmane.org, kernel-WeLdAqEWwDvk1uMJSBkQmQ@public.gmane.org On Wed 2022-04-27 19:49:15, Guilherme G. Piccoli wrote: > This patch renames the panic_notifier_list to panic_pre_reboot_list; > the idea is that a subsequent patch will refactor the panic path > in order to better split the notifiers, running some of them very > early, some of them not so early [but still before kmsg_dump()] and > finally, the rest should execute late, after kdump. The latter ones > are now in the panic pre-reboot list - the name comes from the idea > that these notifiers execute before panic() attempts rebooting the > machine (if that option is set). > > We also took the opportunity to clean-up useless header inclusions, > improve some notifier block declarations (e.g. in ibmasm/heartbeat.c) > and more important, change some priorities - we hereby set 2 notifiers > to run late in the list [iss_panic_event() and the IPMI panic_event()] > due to the risks they offer (may not return, for example). > Proper documentation is going to be provided in a subsequent patch, > that effectively refactors the panic path. > > --- a/drivers/edac/altera_edac.c > +++ b/drivers/edac/altera_edac.c > @@ -2163,7 +2162,7 @@ static int altr_edac_a10_probe(struct platform_device *pdev) > int dberror, err_addr; > > edac->panic_notifier.notifier_call = s10_edac_dberr_handler; > - atomic_notifier_chain_register(&panic_notifier_list, > + atomic_notifier_chain_register(&panic_pre_reboot_list, My understanding is that this notifier first prints info about ECC errors and then triggers reboot. It might make sense to split it into two notifiers. > &edac->panic_notifier); > > /* Printout a message if uncorrectable error previously. */ > --- a/drivers/leds/trigger/ledtrig-panic.c > +++ b/drivers/leds/trigger/ledtrig-panic.c > @@ -64,7 +63,7 @@ static long led_panic_blink(int state) > > static int __init ledtrig_panic_init(void) > { > - atomic_notifier_chain_register(&panic_notifier_list, > + atomic_notifier_chain_register(&panic_pre_reboot_list, > &led_trigger_panic_nb); Blinking => should go to the last "post_reboot/loop" list. > > led_trigger_register_simple("panic", &trigger); > --- a/drivers/misc/ibmasm/heartbeat.c > +++ b/drivers/misc/ibmasm/heartbeat.c > @@ -32,20 +31,23 @@ static int suspend_heartbeats = 0; > static int panic_happened(struct notifier_block *n, unsigned long val, void *v) > { > suspend_heartbeats = 1; > - return 0; > + return NOTIFY_DONE; > } > > -static struct notifier_block panic_notifier = { panic_happened, NULL, 1 }; > +static struct notifier_block panic_notifier = { > + .notifier_call = panic_happened, > +}; > > void ibmasm_register_panic_notifier(void) > { > - atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier); > + atomic_notifier_chain_register(&panic_pre_reboot_list, > + &panic_notifier); Same here. Blinking => should go to the last "post_reboot/loop" list. > } > > void ibmasm_unregister_panic_notifier(void) > { > - atomic_notifier_chain_unregister(&panic_notifier_list, > - &panic_notifier); > + atomic_notifier_chain_unregister(&panic_pre_reboot_list, > + &panic_notifier); > } The rest of the moved notifiers seem to fit well this "pre_reboot" list. Best Regards, Petr