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

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

[Roland Dreier]

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@cisco.com>
---
 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;
 	}
 

[tip:x86/urgent] x86: Reduce verbosity of "TSC is reliable" message

[tip-bot for Roland Dreier]

Commit-ID:  ea01c0d7315d6e3218fd22a6947c5b09305fcf65
Gitweb:     http://git.kernel.org/tip/ea01c0d7315d6e3218fd22a6947c5b09305fcf65
Author:     Roland Dreier <rdreier@cisco.com>
AuthorDate: Wed, 23 Sep 2009 15:33:23 -0700
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 24 Sep 2009 11:35:19 +0200

x86: Reduce verbosity of "TSC is reliable" message

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@cisco.com>
LKML-Reference: <adazl8l2swc.fsf@cisco.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
 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;
 	}