|
xen-devel
Re: [Xen-devel] [PATCH]ACPI: re-enable mwait for xen cpuidle
On 04/01/2010 07:38 PM, Wei, Gang wrote:
I suggest including this patch in Xen 4.0 release. It is quite straightforward,
and make sure the better and widely equipped cpu idle entry method MWAIT is
used by xen if available.
BTW, can we consider re-open MWAIT freature for dom0 in xen hypervisor? We can
discuss it post 4.0.
Jimmy
ACPI: re-enable mwait for xen cpuidle
Xen hypervisor doesn't export mwait feature to dom0, but latest Linux kernel
start to check this feature while initializing _PDC object. Bypass such check
in pv-ops case to re-enable mwait for xen cpuidle.
Why not just set or clear the MWAIT feature flag in xen_cpuid?
J
Signed-off-by: Wei Gang<gang.wei@xxxxxxxxx>
Signed-off-by: Yu Ke<ke.yu@xxxxxxxxx>
diff --git a/arch/x86/kernel/acpi/processor.c b/arch/x86/kernel/acpi/processor.c
index 8c9526d..d88866c 100644
--- a/arch/x86/kernel/acpi/processor.c
+++ b/arch/x86/kernel/acpi/processor.c
@@ -60,7 +60,7 @@ static void init_intel_pdc(struct acpi_processor *pr, struct
cpuinfo_x86 *c)
/*
* If mwait/monitor is unsupported, C2/C3_FFH will be disabled
*/
- if (!cpu_has(c, X86_FEATURE_MWAIT))
+ if (!cpu_has(c, X86_FEATURE_MWAIT)&& !xen_initial_domain())
buf[2]&= ~(ACPI_PDC_C_C2C3_FFH);
obj->type = ACPI_TYPE_BUFFER;
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 22baf4c..0a81637 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -419,7 +419,8 @@ static int acpi_processor_get_power_info_cst(struct
acpi_processor *pr)
cx.entry_method = ACPI_CSTATE_HALT;
snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
} else {
- continue;
+ if (!xen_initial_domain())
+ continue;
}
if (cx.type == ACPI_STATE_C1&&
(idle_halt || idle_nomwait)) {
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
Home