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authorMauro Carvalho Chehab <mchehab@redhat.com>2012-11-28 07:22:38 -0200
committerMauro Carvalho Chehab <mchehab@redhat.com>2012-11-28 07:22:38 -0200
commitd033a308d81ec83908760a15a841c2bd0d5e0ea3 (patch)
tree647abd67987fe4d7fee80105fc823edf3f53b4f6 /arch/x86/kernel/cpu/amd.c
parentc6c22955f80f2db9614b01fe5a3d1cfcd8b3d848 (diff)
parente23739b4ade80a3a7f87198f008f6c44a7cbc9fd (diff)
Merge remote-tracking branch 'linus/master' into staging/for_v3.8
* linus/master: (1428 commits) futex: avoid wake_futex() for a PI futex_q watchdog: using u64 in get_sample_period() writeback: put unused inodes to LRU after writeback completion mm: vmscan: check for fatal signals iff the process was throttled Revert "mm: remove __GFP_NO_KSWAPD" proc: check vma->vm_file before dereferencing UAPI: strip the _UAPI prefix from header guards during header installation include/linux/bug.h: fix sparse warning related to BUILD_BUG_ON_INVALID Linux 3.7-rc7 powerpc/eeh: Do not invalidate PE properly ALSA: hda - Fix build without CONFIG_PM of/address: sparc: Declare of_iomap as an extern function for sparc again PM / QoS: fix wrong error-checking condition bnx2x: remove redundant warning log vxlan: fix command usage in its doc 8139cp: revert "set ring address before enabling receiver" MPI: Fix compilation on MIPS with GCC 4.4 and newer MIPS: Fix crash that occurs when function tracing is enabled MIPS: Merge overlapping bootmem ranges jbd: Fix lock ordering bug in journal_unmap_buffer() ...
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 f7e98a2c0d12..1b7d1656a042 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? */