Message ID | 1355373971-3105-1-git-send-email-herton.krzesinski@canonical.com |
---|---|
State | New |
Headers | show |
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 146bb62..6b4976b 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -598,6 +598,20 @@ 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; + checking_wrmsrl(0xc0011021, val); + } + } + cpu_detect_cache_sizes(c); /* Multi core CPU? */