From: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Date: Tue, 15 Aug 2017 18:00:42 -0700
Subject: x86/intel_rdt/mbm: Fix MBM overflow handler during CPU hotplug
Git-commit: bbc4615e0b7df5e21d0991adb4b2798508354924
Patch-mainline: v4.14-rc1
References: fate#323965
When a CPU is dying, the overflow worker is canceled and rescheduled on a
different CPU in the same domain. But if the timer is already about to
expire this essentially doubles the interval which might result in a non
detected overflow.
Cancel the overflow worker and reschedule it immediately on a different CPU
in same domain. The work could be flushed as well, but that would
reschedule it on the same CPU.
[ tglx: Rewrote changelog once again ]
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: vikas.shivappa@intel.com
Cc: ak@linux.intel.com
Cc: davidcc@google.com
Link: http://lkml.kernel.org/r/1502845243-20454-2-git-send-email-vikas.shivappa@linux.intel.com
Acked-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/cpu/intel_rdt.c | 4 ++--
arch/x86/kernel/cpu/intel_rdt.h | 2 +-
arch/x86/kernel/cpu/intel_rdt_monitor.c | 4 ++--
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 2 +-
4 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index 97c8d8321e04..b8dc141896b6 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -447,7 +447,7 @@ static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_domain *d)
if (is_mbm_enabled()) {
INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow);
- mbm_setup_overflow_handler(d);
+ mbm_setup_overflow_handler(d, MBM_OVERFLOW_INTERVAL);
}
return 0;
@@ -540,7 +540,7 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r)
} else if (r == &rdt_resources_all[RDT_RESOURCE_L3] &&
cpu == d->mbm_work_cpu && is_mbm_enabled()) {
cancel_delayed_work(&d->mbm_over);
- mbm_setup_overflow_handler(d);
+ mbm_setup_overflow_handler(d, 0);
}
}
diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index 4040bf1a075c..3e4869390603 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -422,7 +422,7 @@ void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
struct rdt_domain *d);
void mon_event_read(struct rmid_read *rr, struct rdt_domain *d,
struct rdtgroup *rdtgrp, int evtid, int first);
-void mbm_setup_overflow_handler(struct rdt_domain *dom);
+void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms);
void mbm_handle_overflow(struct work_struct *work);
#endif /* _ASM_X86_INTEL_RDT_H */
diff --git a/arch/x86/kernel/cpu/intel_rdt_monitor.c b/arch/x86/kernel/cpu/intel_rdt_monitor.c
index d6bfdfd22abe..8378785883dc 100644
--- a/arch/x86/kernel/cpu/intel_rdt_monitor.c
+++ b/arch/x86/kernel/cpu/intel_rdt_monitor.c
@@ -417,9 +417,9 @@ void mbm_handle_overflow(struct work_struct *work)
mutex_unlock(&rdtgroup_mutex);
}
-void mbm_setup_overflow_handler(struct rdt_domain *dom)
+void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms)
{
- unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL);
+ unsigned long delay = msecs_to_jiffies(delay_ms);
int cpu;
if (!static_branch_likely(&rdt_enable_key))
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 86a69794d7e4..b529f93e8ed0 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -1140,7 +1140,7 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type,
if (is_mbm_enabled()) {
r = &rdt_resources_all[RDT_RESOURCE_L3];
list_for_each_entry(dom, &r->domains, list)
- mbm_setup_overflow_handler(dom);
+ mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL);
}
goto out;