[PATCH 1/1] csky: add page fault perf event support

[Mao Han]

This patch add support for page fault count, major fault count
and minorfault count. Without this patch page faults are not
sampled for perf event.

 Performance counter stats for '/usr/lib/perf-test/callchain_test':
                 0      page-faults               #    0.000 K/sec

Signed-off-by: Mao Han <han_...@c-sky.com>
---
 arch/csky/mm/fault.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c
index e1725f8..d07141d 100644
--- a/arch/csky/mm/fault.c
+++ b/arch/csky/mm/fault.c
@@ -17,6 +17,7 @@
 #include <linux/vt_kern.h>
 #include <linux/extable.h>
 #include <linux/uaccess.h>
+#include <linux/perf_event.h>
 
 #include <asm/hardirq.h>
 #include <asm/mmu_context.h>
@@ -106,6 +107,8 @@ asmlinkage void do_page_fault(struct pt_regs *regs, 
unsigned long write,
                return;
        }
 #endif
+
+       perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
        /*
         * If we're in an interrupt or have no user
         * context, we must not take the fault..
@@ -153,10 +156,15 @@ asmlinkage void do_page_fault(struct pt_regs *regs, 
unsigned long write,
                        goto bad_area;
                BUG();
        }
-       if (fault & VM_FAULT_MAJOR)
+       if (fault & VM_FAULT_MAJOR) {
                tsk->maj_flt++;
-       else
+               perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
+                             address);
+       } else {
                tsk->min_flt++;
+               perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs,
+                             address);
+       }
 
        up_read(&mm->mmap_sem);
        return;
-- 
2.7.4