From: Philippe E. <ph...@wa...> - 2007-11-06 16:50:10
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On Sat, 21 Jul 2007 at 16:27 +0000, John Levon wrote: > On Sat, Jul 21, 2007 at 11:21:13AM -0400, William Cohen wrote: > > > That patch is the patch mentioned november 17, "Multiple users of the > > performance counters". It adjusts the allocation mechanism to only use the > > registers that are actually available. This became an issue with the watchdog > > timer code grabbing one of the performance counters. I am not sure why it wasn't > > actually checked in. > > They broke userspace compatibility. Haven't they fixed that yet? It's fixed and I'm happy with the used solution, I understand now where the confusion come from. CONFIG_WATCHDOG=no is no longer sufficient, nowaday it means don't build driver for hardware watchdog, the watchdog through local/io apic is always built in if an apic is present so always true with SMP. I did not look why boot params no longer works, quite possible it has been broken only in some kernel version and work now, anyway the right way is: echo 0 > /proc/sys/kernel/nmi_watchdog which is lot better than the old solution. People getting this problem must also do an opcontrol --deinit, because the driver is incorrectly initialized in such case. Will I did that http://oprofile.cvs.sourceforge.net/oprofile/oprofile/utils/opcontrol?r1=1.146&r2=1.147 in opcontrol, it breaks your patch for RH. If you want to continue to use your patch in RH you'll need to turn it as a warning ala "if you want to use all counter do echo .... " and do not error out. John, do we want to save /proc/sys/kernel/nmi_watchdog and restore it at opcontrol --deinit time and hide this thing ? -- regards, Philippe Elie |