From: Rhythm Mahajan Date: Wed, 15 Mar 2023 10:40:15 +0000 (-0700) Subject: x86/cpu: Fix LFENCE serialization check in init_amd() X-Git-Tag: v4.14.310~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9e1f4df32ee8738b6781464a706c16f57ce0d68f;p=thirdparty%2Fkernel%2Fstable.git x86/cpu: Fix LFENCE serialization check in init_amd() The commit: 3f235279828c ("x86/cpu: Restore AMD's DE_CFG MSR after resume") which was backported from the upstream commit: 2632daebafd0 renamed the MSR_F10H_DECFG_LFENCE_SERIALIZE macro to MSR_AMD64_DE_CFG_LFENCE_SERIALIZE. The fix for 4.14 and 4.9 changed MSR_F10H_DECFG_LFENCE_SERIALIZE to MSR_AMD64_DE_CFG_LFENCE_SERIALIZE_BIT in the init_amd() function, but should have used MSR_AMD64_DE_CFG_LFENCE_SERIALIZE. This causes a discrepency in the LFENCE serialization check in the init_amd() function. This causes a ~16% sysbench memory regression, when running: sysbench --test=memory run Fixes: 3f235279828c ("x86/cpu: Restore AMD's DE_CFG MSR after resume") Signed-off-by: Rhythm Mahajan Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 265d9c05bb329..e0c9ede0196a6 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -950,7 +950,7 @@ static void init_amd(struct cpuinfo_x86 *c) * serializing. */ ret = rdmsrl_safe(MSR_AMD64_DE_CFG, &val); - if (!ret && (val & MSR_AMD64_DE_CFG_LFENCE_SERIALIZE_BIT)) { + if (!ret && (val & MSR_AMD64_DE_CFG_LFENCE_SERIALIZE)) { /* A serializing LFENCE stops RDTSC speculation */ set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC); } else {