Commit 2d0640b4 authored Jan 18, 2011 by Stephen Boyd Committed by Ingo Molnar Jan 19, 2011

hrtimers: Notify hrtimer users of switches to NOHZ mode



When NOHZ=y and high res timers are disabled (via cmdline or
Kconfig) tick_nohz_switch_to_nohz() will notify the user about
switching into NOHZ mode. Nothing is printed for the case where
HIGH_RES_TIMERS=y. Fix this for the HIGH_RES_TIMERS=y case by
duplicating the printk from the low res NOHZ path in the high
res NOHZ path.

This confused me since I was thinking 'dmesg | grep -i NOHZ' would
tell me if NOHZ was enabled, but if I have hrtimers there is
nothing.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1295419594-13085-1-git-send-email-sboyd@codeaurora.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent c56eb8fb

kernel/time/tick-sched.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -642,8 +642,7 @@ static void tick_nohz_switch_to_nohz(void)
		}
		local_irq_enable();

		printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n",
		smp_processor_id());
		printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n", smp_processor_id());
		}

		/*
		@@ -795,8 +794,10 @@ void tick_setup_sched_timer(void)
		}

		#ifdef CONFIG_NO_HZ
		if (tick_nohz_enabled)
		if (tick_nohz_enabled) {
		ts->nohz_mode = NOHZ_MODE_HIGHRES;
		printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n", smp_processor_id());
		}
		#endif
		}
		#endif /* HIGH_RES_TIMERS */

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