[PATCH 1/2] x86: Reduce verbosity of "TSC is reliable" message

From: Roland Dreier
Date: Wed Sep 23 2009 - 18:36:34 EST


On modern systems, the kernel prints the message

Skipping synchronization checks as TSC is reliable.

once for every non-boot CPU. This gets kind of ridiculous on huge
systems; for example, on a 64-thread system I was lucky enough to get:

$ dmesg | grep 'TSC is reliable' | wc
63 567 4221

There's no point to doing this for every CPU, since the code is just
checking the boot CPU anyway, so change this to a printk_once() to make
the message appears only once.

Signed-off-by: Roland Dreier <rolandd@xxxxxxxxx>
---
arch/x86/kernel/tsc_sync.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/tsc_sync.c b/arch/x86/kernel/tsc_sync.c
index 027b5b4..f379309 100644
--- a/arch/x86/kernel/tsc_sync.c
+++ b/arch/x86/kernel/tsc_sync.c
@@ -114,7 +114,7 @@ void __cpuinit check_tsc_sync_source(int cpu)
return;

if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE)) {
- pr_info("Skipping synchronization checks as TSC is reliable.\n");
+ printk_once(KERN_INFO "Skipping synchronization checks as TSC is reliable.\n");
return;
}

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