Messages in this thread Patch in this message | | | Subject | [PATCH] nohz: Do not warn about unstable tsc unless user uses nohz_full | From | Steven Rostedt <> | Date | Tue, 16 Jul 2013 10:22:12 -0400 |
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If the user enables CONFIG_NO_HZ_FULL and runs the kernel on a machine with an unstable TSC, it will produce a WARN_ON dump as well as taint the kernel. This is a bit extreme for a kernel that just enables a feature but doesn't use it.
The warning should only happen if the user tries to use the feature by either adding nohz_full to the kernel command line, or by enabling CONFIG_NO_HZ_FULL_ALL that makes nohz used on all CPUs at boot up. Note, this second feature should not (yet) be used by distros or anyone that doesn't care if NO_HZ is used or not.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 6960172..6f47049 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -182,7 +182,8 @@ static bool can_stop_full_tick(void) * Don't allow the user to think they can get * full NO_HZ with this machine. */ - WARN_ONCE(1, "NO_HZ FULL will not work with unstable sched clock"); + WARN_ONCE(have_nohz_full_mask, + "NO_HZ FULL will not work with unstable sched clock"); return false; } #endif
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