On Wed, Jun 21, 2017 at 12:40:28PM +0000, Liang, Kan wrote: > > > > > > > The right fix for mainline can be found here. > > > perf/x86/intel: enable CPU ref_cycles for GP counter perf/x86/intel, > > > watchdog: Switch NMI watchdog to ref cycles on x86 > > > https://patchwork.kernel.org/patch/9779087/ > > > https://patchwork.kernel.org/patch/9779089/ > > > > Presumably the "right fix" will later be altered to revert this one-line > > workaround? > > The "right fix" itself will not touch the watchdog rate. I will modify the > changelog to notify the people who want to do the backport. > > As my understanding, it's not harmful even if we don't revert the > workaround. It can still detect the hardlockup, only takes > a tiny bit longer. It depends on you perspective of harmful. :-) There are folks that would like that sampling rate to be more accurate, so they can detect problems soon than later. You just took an input of 'watchdog_thresh' and blindly multiplied it by 3, which can confuse an end user who thought they setup a 5 second threshold but instead it turned into a 15 second one. :-( Cheers, Don