Date: Tue, 29 Jul 2003 16:06:24 -0500 From: Sean Kelly <smkelly@freebsd.org> To: Doug Ambrisko <ambrisko@ambrisko.com> Cc: Julian Elischer <julian@elischer.org> Subject: Re: Remove "options HW_WDOG"? Message-ID: <20030729210624.GA45102@edgemaster.zombie.org> In-Reply-To: <200307292043.h6TKhBIh078195@www.ambrisko.com> References: <Pine.BSF.4.21.0307231734360.60197-100000@InterJet.elischer.org> <200307292043.h6TKhBIh078195@www.ambrisko.com>
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First, I apologize for the original crosspost between -current and -arch. On Tue, Jul 29, 2003 at 01:43:11PM -0700, Doug Ambrisko wrote: > Julian Elischer writes: > | this code WAS used in the interjet. > | We had modules that linked in and just needed somewhere to hook into.. > | the hardware watchdog was held off by our software, but we needed to add > | code to the core-dump routines to routinely call the watchdog hold-off > | or we could never get a coredump because the watchdog would always go > | off before the dump was completed. > | > | I doubt it is used by anyone any more but It's good that you asked.. > | I did notice some people were working on the watchdog support for the > | chipsets that have a watchdog in them so I guess they wil have all their > | own entrypoints. My basic point is that nothing in the 5.x tree uses the HW_WDOG knob anymore. As Bruce Evans kindly pointed out, the only use of HW_WDOG is in FreeBSD 4.x in i386/isa/wd.c, pc98/pc98/wd.c, and kern/kern_shutdown.c to "tickle" the watchdog in the middle of a crashdump. The 'wd' driver has since died and gone on to a better place, and kern_shutdown.c doesn't use HW_WDOG to call a 'tickle' function anymore. Why have an option if nothing in our tree actually uses it beyond defining a tickle function type (watchdog_tickle_fn) which is never used? If somebody is actually porting a watchdog patch from 4.x to 5.x, they have enough code to change that needing to implement their own tickle option and function should be no big deal. Is there really a reason to keep this around? Can't it be purged for a better (and complete) implementation by hardware watchdog developers? > Most sane watchdogs let you disable them. The ones I've implemented > allow this. I then added code to the panic/debugger code to disable > consmute and disable the watchdog. The old HW_WDOG code also assumed that tickling was necessary during a crashdump, though it only worked for ATA disks. There was no framework for traits such as whether a watchdog can be disabled and reenabled. I just see the current HW_WDOG bits that are still hanging around as debris that needs cleaned up since it is no longer working or used by anything in the source tree. -- Sean Kelly | PGP KeyID: D2E5E296 smkelly@FreeBSD.org | http://www.sean-kelly.org/
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