Messages in this thread Patch in this message | | | From | Xiaochen Shen <> | Subject | [PATCH RESEND] x86/resctrl: Check monitoring static key in MBM overflow handler | Date | Thu, 12 Dec 2019 04:05:05 +0800 |
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Currently, there are three static keys in resctrl file system: rdt_mon_enable_key and rdt_alloc_enable_key indicate if monitoring feature and allocation feature is enabled respectively. rdt_enable_key is enabled when either monitoring feature or allocation feature is enabled.
If no monitoring feature is supported (either hardware doesn't support monitoring feature or the feature is disabled by kernel command line option "rdt="), rdt_enable_key is still enabled but rdt_mon_enable_key is disabled.
MBM is a monitoring feature. MBM overflow handler intends to check if monitoring feature is not enabled for fast return. So the accurate check here is to check rdt_mon_enable_key instead of rdt_enable_key.
Fixes: e33026831bdb ("x86/intel_rdt/mbm: Handle counter overflow") Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com> --- arch/x86/kernel/cpu/resctrl/internal.h | 1 + arch/x86/kernel/cpu/resctrl/monitor.c | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index e49b77283924..181c992f448c 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -57,6 +57,7 @@ static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc) } DECLARE_STATIC_KEY_FALSE(rdt_enable_key); +DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key); /** * struct mon_evt - Entry in the event list of a resource diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 397206f23d14..773124b0e18a 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -514,7 +514,7 @@ void mbm_handle_overflow(struct work_struct *work) mutex_lock(&rdtgroup_mutex); - if (!static_branch_likely(&rdt_enable_key)) + if (!static_branch_likely(&rdt_mon_enable_key)) goto out_unlock; d = get_domain_from_cpu(cpu, &rdt_resources_all[RDT_RESOURCE_L3]); @@ -543,7 +543,7 @@ void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms) unsigned long delay = msecs_to_jiffies(delay_ms); int cpu; - if (!static_branch_likely(&rdt_enable_key)) + if (!static_branch_likely(&rdt_mon_enable_key)) return; cpu = cpumask_any(&dom->cpu_mask); dom->mbm_work_cpu = cpu; -- 1.8.3.1
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