diff options
| author | Xiaochen Shen <xiaochen.shen@intel.com> | 2019-12-12 04:05:05 +0800 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-01-17 19:32:32 +0100 |
| commit | 536a0d8e79fb928f2735db37dda95682b6754f9a (patch) | |
| tree | 94518299f8858529b18a3d82213989936e8a55bb /arch/x86/kernel | |
| parent | dc433797c6f639e46824585bbf943578f13d54bf (diff) | |
x86/resctrl: Check monitoring static key in the MBM overflow handler
Currently, there are three static keys in the resctrl file system:
rdt_mon_enable_key and rdt_alloc_enable_key indicate if the monitoring
feature and the allocation feature are enabled, respectively. The
rdt_enable_key is enabled when either the monitoring feature or the
allocation feature is enabled.
If no monitoring feature is present (either hardware doesn't support a
monitoring feature or the feature is disabled by the kernel command line
option "rdt="), rdt_enable_key is still enabled but rdt_mon_enable_key
is disabled.
MBM is a monitoring feature. The MBM overflow handler intends to
check if the monitoring feature is not enabled for fast return.
So check the rdt_mon_enable_key in it instead of the rdt_enable_key as
former is the more accurate check.
[ bp: Massage commit message. ]
Fixes: e33026831bdb ("x86/intel_rdt/mbm: Handle counter overflow")
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1576094705-13660-1-git-send-email-xiaochen.shen@intel.com
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/resctrl/internal.h | 1 | ||||
| -rw-r--r-- | 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; |