Commit 9b3660a5 authored Nov 17, 2009 by Mike Travis Committed by Ingo Molnar Nov 26, 2009

x86: Limit number of per cpu TSC sync messages



Limit the number of per cpu TSC sync messages by only printing
to the console if an error occurs, otherwise print as a DEBUG
message.

The info message "Skipping synchronization ..." is only printed
after the last cpu has booted.

Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091118002222.181053000@alcatraz.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 67f2de0b

arch/x86/kernel/tsc_sync.c

+7 −6

Original line number	Diff line number	Diff line
		@@ -114,13 +114,12 @@ void __cpuinit check_tsc_sync_source(int cpu)
		return;

		if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE)) {
		printk_once(KERN_INFO "Skipping synchronization checks as TSC is reliable.\n");
		if (cpu == (nr_cpu_ids-1) \|\| system_state != SYSTEM_BOOTING)
		pr_info(
		"Skipped synchronization checks as TSC is reliable.\n");
		return;
		}

		pr_info("checking TSC synchronization [CPU#%d -> CPU#%d]:",
		smp_processor_id(), cpu);

		/*
		* Reset it - in case this is a second bootup:
		*/
		@@ -142,12 +141,14 @@ void __cpuinit check_tsc_sync_source(int cpu)
		cpu_relax();

		if (nr_warps) {
		printk("\n");
		pr_warning("TSC synchronization [CPU#%d -> CPU#%d]:\n",
		smp_processor_id(), cpu);
		pr_warning("Measured %Ld cycles TSC warp between CPUs, "
		"turning off TSC clock.\n", max_warp);
		mark_tsc_unstable("check_tsc_sync_source failed");
		} else {
		printk(" passed.\n");
		pr_debug("TSC synchronization [CPU#%d -> CPU#%d]: passed\n",
		smp_processor_id(), cpu);
		}

		/*