On Fri, 10 Apr 2015 16:48:18 -0400 Chris Metcalf <cmetcalf@xxxxxxxxxx> wrote: > This change allows some cores to be excluded from running the > smp_hotplug_thread tasks. The motivating example for this is > the watchdog threads, which by default we don't want to run > on any enabled nohz_full cores. Why not? I can guess, but I'd rather not guess. Please fully explain the end-user value of this change. Providing a benefit to users is the whole point of the patchset, but the above assertion is the only description we have. This info should be in Documentation/lockup-watchdogs.txt and/or Documentation/sysctl/kernel.txt as well as the changelogs, so users have an answer to "why the heck should I enable this". Please also describe the downside of the change. I assume this is "lockups will go undetected on some CPUs"? Let's expand on this so we can understand where the best tradeoff point lies. If people are experiencing <whatever this problem is> then they can disable the watchdog altogether. What value is there in this partial disabling? Why is it worth doing this? -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
