2012-10-25 09:28:16

by Ivan Hu

Subject: [PATCH] x86, intel, power: Modify the MSR_IA32_ENERGY_PERF_BIAS message from warning to info

Intel IA32 program guild doesn't mention that this MSR should be set by
BIOS, instead, it mentions "Software can use whatever criteria it sees
fit to program the MSR with the appropriate value.". Discuss with IBV,
they'd like to keep this MSR as default, and let OS to change value if desired.
This message should be more proper set as an info than a warning.

Signed-off-by: Ivan Hu <[email protected]>
---
arch/x86/kernel/cpu/intel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 198e019..2bdc6bf 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -466,7 +466,7 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)

rdmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
if ((epb & 0xF) == ENERGY_PERF_BIAS_PERFORMANCE) {
- printk_once(KERN_WARNING "ENERGY_PERF_BIAS:"
+ printk_once(KERN_INFO "ENERGY_PERF_BIAS:"
" Set to 'normal', was 'performance'\n"
"ENERGY_PERF_BIAS: View and update with"
" x86_energy_perf_policy(8)\n");
--
1.7.10.4

2012-10-25 09:49:19

by Borislav Petkov

Subject: Re: [PATCH] x86, intel, power: Modify the MSR_IA32_ENERGY_PERF_BIAS message from warning to info

On Thu, Oct 25, 2012 at 05:28:00PM +0800, Ivan Hu wrote:
> Intel IA32 program guild doesn't mention that this MSR should be set by
> BIOS, instead, it mentions "Software can use whatever criteria it sees
> fit to program the MSR with the appropriate value.". Discuss with IBV,
> they'd like to keep this MSR as default, and let OS to change value if desired.
> This message should be more proper set as an info than a warning.

What is the difference? It'll appear in default dmesg loglevel settings
anyway.

> Signed-off-by: Ivan Hu <[email protected]>
> ---
> arch/x86/kernel/cpu/intel.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
> index 198e019..2bdc6bf 100644
> --- a/arch/x86/kernel/cpu/intel.c
> +++ b/arch/x86/kernel/cpu/intel.c
> @@ -466,7 +466,7 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)
>
> rdmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
> if ((epb & 0xF) == ENERGY_PERF_BIAS_PERFORMANCE) {
> - printk_once(KERN_WARNING "ENERGY_PERF_BIAS:"
> + printk_once(KERN_INFO "ENERGY_PERF_BIAS:"

While you're at it, you can do pr_info_once to shorten this line a bit.

> " Set to 'normal', was 'performance'\n"
> "ENERGY_PERF_BIAS: View and update with"
> " x86_energy_perf_policy(8)\n");
> --
> 1.7.10.4

--
Regards/Gruss,
Boris.