summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/cpu/amd.c
diff options
context:
space:
mode:
authorIngo Molnar <mingo@kernel.org>2012-12-08 15:25:06 +0100
committerIngo Molnar <mingo@kernel.org>2012-12-08 15:25:06 +0100
commitf0b9abfb044649bc452fb2fb975ff2fd599cc6a3 (patch)
tree7800081c5cb16a4dfee1e57a70f3be90f7b50d9a /arch/x86/kernel/cpu/amd.c
parentadc1ef1e37358d3c17d1a74a58b2e104fc0bda15 (diff)
parent1b3c393cd43f22ead8a6a2f839efc6df8ebd7465 (diff)
downloadop-kernel-dev-f0b9abfb044649bc452fb2fb975ff2fd599cc6a3.zip
op-kernel-dev-f0b9abfb044649bc452fb2fb975ff2fd599cc6a3.tar.gz
Merge branch 'linus' into perf/core
Conflicts: tools/perf/Makefile tools/perf/builtin-test.c tools/perf/perf.h tools/perf/tests/parse-events.c tools/perf/util/evsel.h 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 f7e98a2..1b7d165 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? */
OpenPOWER on IntegriCloud