From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 15 Jan 2001 15:27:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 15 Jan 2001 15:27:03 -0500 Received: from harpo.it.uu.se ([130.238.12.34]:43949 "EHLO harpo.it.uu.se") by vger.kernel.org with ESMTP id ; Mon, 15 Jan 2001 15:26:51 -0500 Date: Mon, 15 Jan 2001 21:26:45 +0100 (MET) From: Mikael Pettersson Message-Id: <200101152026.VAA03317@harpo.it.uu.se> To: mikpe@csd.uu.se, vandrove@vc.cvut.cz Subject: Re: [PATCH] enable K7 nmi watchdog Cc: alan@redhat.com, linux-kernel@vger.kernel.org, mingo@redhat.com Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 15 Jan 2001 04:00:29 +0100, Petr Vandrovec wrote: >(1) You missed some zeros in MSR_K7_ definitions Oops :-( >(2) AMD's MSR are real 64bit (well, 47bit) values, so high > MSR dword must be set to -1, not to 0 Correct. That was a copy-paste error from the P6 code. When writing to a perfctr MSR, Intel P6 sign-extends bit 31. P5 and Pentium 4 [*], and AMD K7 don't sign-extend, so there one has to pass -1 in the high word. [*] P4? PIV? P15? NB? Oh why oh why couldn't they just have named the core P7 ... >(3) on my CPU performance register 0x76 counts who knows what... > This causes that when machine is idle, there is exactly one > NMI per second. When machine is loaded, NMI count/sec climbs > up to 100 NMIs per sec. I have no idea whether someone slows > clock down to 10MHz on hlt, or what happens. Maybe that they > removed this from documentation due to this. This also means > that on bootup check for NMI stuck probably passed only > due to pure luck - because of mdelay()/udelay() is implemented > as tight loop. The varying speed of this counter is unfortunate, but at least it doesn't stop completely. The NMI oopser should still trigger, although perhaps after a much longer delay. >Otherwise it works Great. Thanks. /Mikael - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/