| Message ID | 36183132.7cOCK0nhyl@house (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | x86: Do not override performance EPB MSR value on servers | expand |
On Monday, April 8, 2019 10:46:46 AM CEST Thomas Renninger wrote: > It is about this kernel message showing up on quite a lot servers: > [ 0.072652] ENERGY_PERF_BIAS: Set to 'normal', was 'performance' > [ 0.076003] ENERGY_PERF_BIAS: View and update with > x86_energy_perf_policy(8) > > With this patch the EPB value is not overridden anymore on systems > which expose themselves as appliance or enterprise server via ACPI > perferred profile variable. > > Signed-off-by: trenn@suse.de The patch has successfully been tested on top of Rafeals latest EPB fixes: [PATCH 0/2] PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS handling fixes and sysfs i/f EPB value is now successfully and correctly restored after CPU off-/onlining It can be set back to performance value if kernel set it to normal and this value also survives CPU off-/onlining. Still the kernel should not override the performance value on servers, so it would be nice to see the patch applied. Once applied, I may send a patch based on code before EPB changes similar to this for stable kernels. There it is even more urgent, due to the wrong unconditional setting to "normal" value after CPU off-/onlining. I tested the patch to make sure the preferred value is considered and it works. Thomas
On Mon, Apr 8, 2019 at 10:46 AM Thomas Renninger <trenn@suse.de> wrote: > > It is about this kernel message showing up on quite a lot servers: > [ 0.072652] ENERGY_PERF_BIAS: Set to 'normal', was 'performance' > [ 0.076003] ENERGY_PERF_BIAS: View and update with x86_energy_perf_policy(8) > > With this patch the EPB value is not overridden anymore on systems > which expose themselves as appliance or enterprise server via ACPI > perferred profile variable. > > Signed-off-by: trenn@suse.de > > > Index: perf_bias_acpi_server_only/arch/x86/kernel/cpu/intel_epb.c > =================================================================== > --- perf_bias_acpi_server_only.orig/arch/x86/kernel/cpu/intel_epb.c 2019-04-05 14:43:04.280222577 +0200 > +++ perf_bias_acpi_server_only/arch/x86/kernel/cpu/intel_epb.c 2019-04-08 10:01:26.029278425 +0200 > @@ -19,6 +19,8 @@ > #include <asm/cpufeature.h> > #include <asm/msr.h> > > +#include <linux/acpi.h> > + > /** > * DOC: overview > * > @@ -89,7 +91,10 @@ static void intel_epb_restore(void) > * ('normal'). > */ > val = epb & EPB_MASK; > - if (val == ENERGY_PERF_BIAS_PERFORMANCE) { > + if (acpi_gbl_FADT.preferred_profile == PM_ENTERPRISE_SERVER || > + acpi_gbl_FADT.preferred_profile == PM_PERFORMANCE_SERVER) { > + /* Keep performance setting on servers */ > + } else if (val == ENERGY_PERF_BIAS_PERFORMANCE) { I would write this as if (val == ENERGY_PERF_BIAS_PERFORMANCE && acpi_gbl_FADT.preferred_profile != PM_ENTERPRISE_SERVER && acpi_gbl_FADT.preferred_profile != PM_PERFORMANCE_SERVER) { but overall the approach is not particularly objectionable. > val = ENERGY_PERF_BIAS_NORMAL; > pr_warn_once("ENERGY_PERF_BIAS: Set to 'normal', was 'performance'\n"); > } >
Index: perf_bias_acpi_server_only/arch/x86/kernel/cpu/intel_epb.c =================================================================== --- perf_bias_acpi_server_only.orig/arch/x86/kernel/cpu/intel_epb.c 2019-04-05 14:43:04.280222577 +0200 +++ perf_bias_acpi_server_only/arch/x86/kernel/cpu/intel_epb.c 2019-04-08 10:01:26.029278425 +0200 @@ -19,6 +19,8 @@ #include <asm/cpufeature.h> #include <asm/msr.h> +#include <linux/acpi.h> + /** * DOC: overview * @@ -89,7 +91,10 @@ static void intel_epb_restore(void) * ('normal'). */ val = epb & EPB_MASK; - if (val == ENERGY_PERF_BIAS_PERFORMANCE) { + if (acpi_gbl_FADT.preferred_profile == PM_ENTERPRISE_SERVER || + acpi_gbl_FADT.preferred_profile == PM_PERFORMANCE_SERVER) { + /* Keep performance setting on servers */ + } else if (val == ENERGY_PERF_BIAS_PERFORMANCE) { val = ENERGY_PERF_BIAS_NORMAL; pr_warn_once("ENERGY_PERF_BIAS: Set to 'normal', was 'performance'\n"); }
It is about this kernel message showing up on quite a lot servers: [ 0.072652] ENERGY_PERF_BIAS: Set to 'normal', was 'performance' [ 0.076003] ENERGY_PERF_BIAS: View and update with x86_energy_perf_policy(8) With this patch the EPB value is not overridden anymore on systems which expose themselves as appliance or enterprise server via ACPI perferred profile variable. Signed-off-by: trenn@suse.de