[PATCH v4 2/7] mm/gup: add gup trace points

From: Yang Shi
Date: Wed Dec 09 2015 - 12:50:19 EST


For slow version, just add trace point for raw __get_user_pages since all
slow variants call it to do the real work finally.

Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxx>
---
mm/gup.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/mm/gup.c b/mm/gup.c
index deafa2c..00a3cff 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -18,6 +18,9 @@

#include "internal.h"

+#define CREATE_TRACE_POINTS
+#include <trace/events/gup.h>
+
static struct page *no_page_table(struct vm_area_struct *vma,
unsigned int flags)
{
@@ -462,6 +465,8 @@ long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
if (!nr_pages)
return 0;

+ trace_gup_get_user_pages(start, nr_pages);
+
VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET));

/*
@@ -599,6 +604,7 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
if (!(vm_flags & vma->vm_flags))
return -EFAULT;

+ trace_gup_fixup_user_fault(address);
ret = handle_mm_fault(mm, vma, address, fault_flags);
if (ret & VM_FAULT_ERROR) {
if (ret & VM_FAULT_OOM)
@@ -1340,6 +1346,8 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
start, len)))
return 0;

+ trace_gup_get_user_pages_fast(start, nr_pages);
+
/*
* Disable interrupts. We use the nested form as we can already have
* interrupts disabled by get_futex_key.
--
2.0.2

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