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authorMauro Carvalho Chehab <mchehab@redhat.com>2012-12-11 11:18:45 -0200
committerMauro Carvalho Chehab <mchehab@redhat.com>2012-12-11 11:18:45 -0200
commit9374020a78fce13a1cf2edf3d26f6dd7231b5c3d (patch)
tree50c8629e6c6222c5b9681506b52afbde818c5e56 /arch/x86/kernel/cpu/amd.c
parentd2a0db1ee01aea154ccc460e45a16857e32c4427 (diff)
parent29594404d7fe73cd80eaa4ee8c43dcc53970c60e (diff)
Merge tag 'v3.7' into v4l_for_linus
Linux 3.7 * tag 'v3.7': (1545 commits) Linux 3.7 Input: matrix-keymap - provide proper module license Revert "revert "Revert "mm: remove __GFP_NO_KSWAPD""" and associated damage ipv4: ip_check_defrag must not modify skb before unsharing Revert "mm: avoid waking kswapd for THP allocations when compaction is deferred or contended" inet_diag: validate port comparison byte code to prevent unsafe reads inet_diag: avoid unsafe and nonsensical prefix matches in inet_diag_bc_run() inet_diag: validate byte code to prevent oops in inet_diag_bc_run() inet_diag: fix oops for IPv4 AF_INET6 TCP SYN-RECV state mm: vmscan: fix inappropriate zone congestion clearing vfs: fix O_DIRECT read past end of block device net: gro: fix possible panic in skb_gro_receive() tcp: bug fix Fast Open client retransmission tmpfs: fix shared mempolicy leak mm: vmscan: do not keep kswapd looping forever due to individual uncompactable zones mm: compaction: validate pfn range passed to isolate_freepages_block mmc: sh-mmcif: avoid oops on spurious interrupts (second try) Revert misapplied "mmc: sh-mmcif: avoid oops on spurious interrupts" mmc: sdhci-s3c: fix missing clock for gpio card-detect lib/Makefile: Fix oid_registry build dependency ...
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? */