[PATCH 5/5] x86: Limit number of per cpu TSC sync messages

[Mike Travis]

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@xxxxxxx>
---
 arch/x86/kernel/tsc_sync.c |   13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

--- linux.orig/arch/x86/kernel/tsc_sync.c
+++ linux/arch/x86/kernel/tsc_sync.c
@@ -114,13 +114,12 @@
 		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 @@
 		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);
 	}
 
 	/*

-- 
--
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