xen/trace: add xen_pgd_(un)pin tracepoints

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

arch/x86/xen/mmu.c

@@ -885,6 +885,8 @@ static int xen_pin_page(struct mm_struct *mm, struct page *page,
    read-only, and can be pinned. */
 static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd)
 {
+	trace_xen_mmu_pgd_pin(mm, pgd);
+
 	xen_mc_batch();
 
 	if (__xen_pgd_walk(mm, pgd, xen_pin_page, USER_LIMIT)) {
@@ -1010,6 +1012,8 @@ static int xen_unpin_page(struct mm_struct *mm, struct page *page,
 /* Release a pagetables pages back as normal RW */
 static void __xen_pgd_unpin(struct mm_struct *mm, pgd_t *pgd)
 {
+	trace_xen_mmu_pgd_unpin(mm, pgd);
+
 	xen_mc_batch();
 
 	xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));

include/trace/events/xen.h

@@ -381,6 +381,30 @@ TRACE_EVENT(xen_mmu_release_ptpage,
 		      __entry->pinned ? "" : "un")
 	);
 
+TRACE_EVENT(xen_mmu_pgd_pin,
+	    TP_PROTO(struct mm_struct *mm, pgd_t *pgd),
+	    TP_ARGS(mm, pgd),
+	    TP_STRUCT__entry(
+		    __field(struct mm_struct *, mm)
+		    __field(pgd_t *, pgd)
+		    ),
+	    TP_fast_assign(__entry->mm = mm;
+			   __entry->pgd = pgd),
+	    TP_printk("mm %p pgd %p", __entry->mm, __entry->pgd)
+	);
+
+TRACE_EVENT(xen_mmu_pgd_unpin,
+	    TP_PROTO(struct mm_struct *mm, pgd_t *pgd),
+	    TP_ARGS(mm, pgd),
+	    TP_STRUCT__entry(
+		    __field(struct mm_struct *, mm)
+		    __field(pgd_t *, pgd)
+		    ),
+	    TP_fast_assign(__entry->mm = mm;
+			   __entry->pgd = pgd),
+	    TP_printk("mm %p pgd %p", __entry->mm, __entry->pgd)
+	);
+
 #endif /*  _TRACE_XEN_H */
 
 /* This part must be outside protection */