tracing/mm: don't trace mm_page_pcpu_drain on offline cpus

[uclinux-h8/linux.git] / include / trace / events / kmem.h

diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index aa86354..f7554fd 100644 (file)
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -276,12 +276,35 @@ DEFINE_EVENT(mm_page, mm_page_alloc_zone_locked,
        TP_ARGS(page, order, migratetype)
 );
 
-DEFINE_EVENT_PRINT(mm_page, mm_page_pcpu_drain,
+TRACE_EVENT_CONDITION(mm_page_pcpu_drain,
 
        TP_PROTO(struct page *page, unsigned int order, int migratetype),
 
        TP_ARGS(page, order, migratetype),
 
+       /*
+        * This trace can be potentially called from an offlined cpu.
+        * Since trace points use RCU and RCU should not be used from
+        * offline cpus, filter such calls out.
+        * While this trace can be called from a preemptable section,
+        * it has no impact on the condition since tasks can migrate
+        * only from online cpus to other online cpus. Thus its safe
+        * to use raw_smp_processor_id.
+        */
+       TP_CONDITION(cpu_online(raw_smp_processor_id())),
+
+       TP_STRUCT__entry(
+               __field(        unsigned long,  pfn             )
+               __field(        unsigned int,   order           )
+               __field(        int,            migratetype     )
+       ),
+
+       TP_fast_assign(
+               __entry->pfn            = page ? page_to_pfn(page) : -1UL;
+               __entry->order          = order;
+               __entry->migratetype    = migratetype;
+       ),
+
        TP_printk("page=%p pfn=%lu order=%d migratetype=%d",
                pfn_to_page(__entry->pfn), __entry->pfn,
                __entry->order, __entry->migratetype)