From e23a8b6a8f319c0f08b6ccef2dccbb37e7603dc2 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Wed, 23 Sep 2009 15:35:35 -0700 Subject: [PATCH] x86: Reduce verbosity of "PAT enabled" kernel message On modern systems, the kernel prints the message x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106 once for every CPU. This gets kind of ridiculous on huge systems; for example, on a 64-thread system I was lucky enough to get: dmesg| grep 'PAT enabled' | wc 64 704 5174 There is already a BUG() if non-boot CPUs have PAT capabilities that don't match the boot CPU, so just print the message on the boot CPU. (I kept the print after the wrmsrl() that enables PAT, so that the log output continues to mean that the system survived enabling PAT on the boot CPU) Signed-off-by: Roland Dreier Cc: Suresh Siddha Cc: Venkatesh Pallipadi LKML-Reference: Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 7257cf3decf9..e78cd0ec2bcf 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -81,6 +81,7 @@ enum { void pat_init(void) { u64 pat; + bool boot_cpu = !boot_pat_state; if (!pat_enabled) return; @@ -122,8 +123,10 @@ void pat_init(void) rdmsrl(MSR_IA32_CR_PAT, boot_pat_state); wrmsrl(MSR_IA32_CR_PAT, pat); - printk(KERN_INFO "x86 PAT enabled: cpu %d, old 0x%Lx, new 0x%Lx\n", - smp_processor_id(), boot_pat_state, pat); + + if (boot_cpu) + printk(KERN_INFO "x86 PAT enabled: cpu %d, old 0x%Lx, new 0x%Lx\n", + smp_processor_id(), boot_pat_state, pat); } #undef PAT