From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Date: Wed, 14 Dec 2005 23:16:13 +0000 Subject: Re: [PATCH] ia64: eliminate softlockup warning Message-Id: <20051214151613.2afc35b2.akpm@osdl.org> List-Id: References: <20051214230713.7528.68477.sendpatchset@tomahawk.engr.sgi.com> In-Reply-To: <20051214230713.7528.68477.sendpatchset@tomahawk.engr.sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: hawkes@sgi.com Cc: tony.luck@gmail.com, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, steiner@sgi.com, kaos@sgi.com hawkes@sgi.com wrote: > > Fix an unnecessary softlockup watchdog warning in the ia64 > uncached_build_memmap() that occurs occasionally at 256p and always at > 512p. The problem occurs at boot time. > > It would be good if we had a cleaner mechanism to temporarily silence > the watchdog thread, e.g., > http://marc.theaimsgroup.com/?l=linux-kernel&m1552476401175&w=2 > but until that patch gets merged, this fix will have to suffice. > That patch is for the hangcheck timer driver which is unrelated to the softlockup detector. > > Index: linux/arch/ia64/kernel/uncached.c > =================================> --- linux.orig/arch/ia64/kernel/uncached.c 2005-12-06 15:12:14.000000000 -0800 > +++ linux/arch/ia64/kernel/uncached.c 2005-12-14 14:50:55.000000000 -0800 > @@ -210,6 +210,7 @@ > > dprintk(KERN_ERR "uncached_build_memmap(%lx %lx)\n", start, end); > > + touch_softlockup_watchdog(); > memset((char *)start, 0, length); > > node = paddr_to_nid(start - __IA64_UNCACHED_OFFSET); Yes, additions like this are a bit awkward, but they're not _that_ bad. It says "this code is doing something unusual". It's an explicit marker which we can grep for and which conveys useful information about an exceptional kernel state.