From: Reinette Chatre <reinette.chatre@intel.com>
To: tglx@linutronix.de, fenghua.yu@intel.com, bp@alien8.de,
tony.luck@intel.com
Cc: kuo-lang.tseng@intel.com, ravi.v.shankar@intel.com,
mingo@redhat.com, babu.moger@amd.com, hpa@zytor.com,
x86@kernel.org, linux-kernel@vger.kernel.org,
Reinette Chatre <reinette.chatre@intel.com>
Subject: [PATCH V4 2/4] x86/resctrl: Enumerate per-thread MBA
Date: Sat, 16 May 2020 11:28:39 -0700 [thread overview]
Message-ID: <c4e6730bdc35b707cc30a1bba540a05c306c5978.1589652468.git.reinette.chatre@intel.com> (raw)
In-Reply-To: <cover.1589652468.git.reinette.chatre@intel.com>
From: Fenghua Yu <fenghua.yu@intel.com>
Some systems support per-thread Memory Bandwidth Allocation (MBA) which
applies a throttling delay value to each hardware thread instead of to
a core. Per-thread MBA is enumerated by CPUID.
No feature flag is shown in /proc/cpuinfo. User applications need to
check a resctrl throttling mode info file to know if the feature is
supported.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/kernel/cpu/cpuid-deps.c | 1 +
arch/x86/kernel/cpu/scattered.c | 1 +
3 files changed, 3 insertions(+)
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index db189945e9b0..d0ec26ce7f66 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -286,6 +286,7 @@
#define X86_FEATURE_FENCE_SWAPGS_USER (11*32+ 4) /* "" LFENCE in user entry SWAPGS path */
#define X86_FEATURE_FENCE_SWAPGS_KERNEL (11*32+ 5) /* "" LFENCE in kernel entry SWAPGS path */
#define X86_FEATURE_SPLIT_LOCK_DETECT (11*32+ 6) /* #AC for split lock */
+#define X86_FEATURE_PER_THREAD_MBA (11*32+ 7) /* "" Per-thread Memory Bandwidth Allocation */
/* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */
#define X86_FEATURE_AVX512_BF16 (12*32+ 5) /* AVX512 BFLOAT16 instructions */
diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index 3cbe24ca80ab..3e30b26c50ef 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -69,6 +69,7 @@ static const struct cpuid_dep cpuid_deps[] = {
{ X86_FEATURE_CQM_MBM_TOTAL, X86_FEATURE_CQM_LLC },
{ X86_FEATURE_CQM_MBM_LOCAL, X86_FEATURE_CQM_LLC },
{ X86_FEATURE_AVX512_BF16, X86_FEATURE_AVX512VL },
+ { X86_FEATURE_PER_THREAD_MBA, X86_FEATURE_MBA },
{}
};
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index 62b137c3c97a..bccfc9ff3cc1 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -35,6 +35,7 @@ static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_CDP_L3, CPUID_ECX, 2, 0x00000010, 1 },
{ X86_FEATURE_CDP_L2, CPUID_ECX, 2, 0x00000010, 2 },
{ X86_FEATURE_MBA, CPUID_EBX, 3, 0x00000010, 0 },
+ { X86_FEATURE_PER_THREAD_MBA, CPUID_ECX, 0, 0x00000010, 3 },
{ X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 },
{ X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 },
{ X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 },
--
2.21.0
next prev parent reply other threads:[~2020-05-16 18:29 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-16 18:28 [PATCH V4 0/4] x86/resctrl: Enable user to view and select thread throttling mode Reinette Chatre
2020-05-16 18:28 ` [PATCH V4 1/4] " Reinette Chatre
2020-05-18 17:28 ` Babu Moger
2020-05-18 22:46 ` Reinette Chatre
2020-05-16 18:28 ` Reinette Chatre [this message]
2020-05-18 17:29 ` [PATCH V4 2/4] x86/resctrl: Enumerate per-thread MBA Babu Moger
2020-05-16 18:28 ` [PATCH V4 3/4] x86/resctrl: Enable " Reinette Chatre
2020-05-18 17:29 ` Babu Moger
2020-05-16 18:28 ` [PATCH V4 4/4] x86/resctrl: Use appropriate API for strings terminated by newline Reinette Chatre
2020-05-18 11:50 ` Andy Shevchenko
2020-05-18 16:06 ` Reinette Chatre
2020-05-18 16:23 ` Reinette Chatre
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