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authorIngo Molnar <mingo@kernel.org>2012-12-07 12:15:33 +0100
committerIngo Molnar <mingo@kernel.org>2012-12-07 12:15:33 +0100
commit222e82bef4bd520a31d48c31ab24e49dd46daa46 (patch)
treeb6e73cad8e0b3a1c3e1acc537789e97aadaefa92 /arch/x86/kernel/cpu/amd.c
parent38ca9c927c7d3db61f57e3d3a9334958c3af6e9a (diff)
parent18a2f371f5edf41810f6469cb9be39931ef9deb9 (diff)
Merge branch 'linus' into sched/core
Pick up the autogroups fix and other fixes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu/amd.c')
-rw-r--r--arch/x86/kernel/cpu/amd.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index f7e98a2c0d1..1b7d1656a04 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -631,6 +631,20 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
}
}
+ /*
+ * The way access filter has a performance penalty on some workloads.
+ * Disable it on the affected CPUs.
+ */
+ if ((c->x86 == 0x15) &&
+ (c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
+ u64 val;
+
+ if (!rdmsrl_safe(0xc0011021, &val) && !(val & 0x1E)) {
+ val |= 0x1E;
+ wrmsrl_safe(0xc0011021, val);
+ }
+ }
+
cpu_detect_cache_sizes(c);
/* Multi core CPU? */