Commit bbc4615e authored by Vikas Shivappa's avatar Vikas Shivappa Committed by Thomas Gleixner

x86/intel_rdt/mbm: Fix MBM overflow handler during CPU hotplug

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: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarVikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: default avatarThomas 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
parent a9110b55
...@@ -447,7 +447,7 @@ static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_domain *d) ...@@ -447,7 +447,7 @@ static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_domain *d)
if (is_mbm_enabled()) { if (is_mbm_enabled()) {
INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow); INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow);
mbm_setup_overflow_handler(d); mbm_setup_overflow_handler(d, MBM_OVERFLOW_INTERVAL);
} }
return 0; return 0;
...@@ -540,7 +540,7 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r) ...@@ -540,7 +540,7 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r)
} else if (r == &rdt_resources_all[RDT_RESOURCE_L3] && } else if (r == &rdt_resources_all[RDT_RESOURCE_L3] &&
cpu == d->mbm_work_cpu && is_mbm_enabled()) { cpu == d->mbm_work_cpu && is_mbm_enabled()) {
cancel_delayed_work(&d->mbm_over); cancel_delayed_work(&d->mbm_over);
mbm_setup_overflow_handler(d); mbm_setup_overflow_handler(d, 0);
} }
} }
......
...@@ -422,7 +422,7 @@ void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, ...@@ -422,7 +422,7 @@ void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
struct rdt_domain *d); struct rdt_domain *d);
void mon_event_read(struct rmid_read *rr, struct rdt_domain *d, void mon_event_read(struct rmid_read *rr, struct rdt_domain *d,
struct rdtgroup *rdtgrp, int evtid, int first); 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); void mbm_handle_overflow(struct work_struct *work);
#endif /* _ASM_X86_INTEL_RDT_H */ #endif /* _ASM_X86_INTEL_RDT_H */
...@@ -417,9 +417,9 @@ void mbm_handle_overflow(struct work_struct *work) ...@@ -417,9 +417,9 @@ void mbm_handle_overflow(struct work_struct *work)
mutex_unlock(&rdtgroup_mutex); 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; int cpu;
if (!static_branch_likely(&rdt_enable_key)) if (!static_branch_likely(&rdt_enable_key))
......
...@@ -1140,7 +1140,7 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type, ...@@ -1140,7 +1140,7 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type,
if (is_mbm_enabled()) { if (is_mbm_enabled()) {
r = &rdt_resources_all[RDT_RESOURCE_L3]; r = &rdt_resources_all[RDT_RESOURCE_L3];
list_for_each_entry(dom, &r->domains, list) list_for_each_entry(dom, &r->domains, list)
mbm_setup_overflow_handler(dom); mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL);
} }
goto out; goto out;
......
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