xen/23511-amd-fam15-no-flush-for-C3.patch

29 lines
1.0 KiB
Diff
Raw Normal View History

References: FATE#309893
# HG changeset patch
# User Mark Langsdorf <mark.langsdorf@amd.com>
# Date 1308051989 -3600
# Node ID 450f1d198e1e299b69489d513f591f0301cc5166
# Parent 864a3dd1d9b4664f1ece44c9eaf390969253b7a8
x86/amd: Eliminate cache flushing when entering C3 on select AMD processors
AMD Fam15h processors have a shared cache. It does not need
to be be flushed when entering C3 and doing so causes reduces
performance. Modify acpi_processor_power_init_bm_check to
prevent these processors from flushing when entering C3.
Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
--- a/xen/arch/x86/acpi/cpu_idle.c
+++ b/xen/arch/x86/acpi/cpu_idle.c
@@ -680,7 +680,8 @@ static void acpi_processor_power_init_bm
flags->bm_check = 0;
if ( num_online_cpus() == 1 )
flags->bm_check = 1;
- else if ( c->x86_vendor == X86_VENDOR_INTEL )
+ else if ( (c->x86_vendor == X86_VENDOR_INTEL) ||
+ ((c->x86_vendor == X86_VENDOR_AMD) && (c->x86 == 0x15)) )
{
/*
* Today all MP CPUs that support C3 share cache.