[PATCH 10/26] mm/microblaze: Use general page fault accounting

From: Peter Xu
Date: Fri Jun 26 2020 - 18:31:56 EST


Use the general page fault accounting by passing regs into handle_mm_fault().
It naturally solve the issue of multiple page fault accounting when page fault
retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too. Note, the other two
perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in handle_mm_fault().

CC: Michal Simek <monstr@xxxxxxxxx>
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
arch/microblaze/mm/fault.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/microblaze/mm/fault.c b/arch/microblaze/mm/fault.c
index 9abfa5224386..3d58dbd227cd 100644
--- a/arch/microblaze/mm/fault.c
+++ b/arch/microblaze/mm/fault.c
@@ -28,6 +28,7 @@
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
+#include <linux/perf_event.h>

#include <asm/page.h>
#include <asm/pgtable.h>
@@ -122,6 +123,8 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
if (user_mode(regs))
flags |= FAULT_FLAG_USER;

+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
+
/* When running in the kernel we expect faults to occur only to
* addresses in user space. All other faults represent errors in the
* kernel and should generate an OOPS. Unfortunately, in the case of an
@@ -215,7 +218,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
- fault = handle_mm_fault(vma, address, flags, NULL);
+ fault = handle_mm_fault(vma, address, flags, regs);

if (fault_signal_pending(fault, regs))
return;
@@ -231,10 +234,6 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
}

if (flags & FAULT_FLAG_ALLOW_RETRY) {
- if (unlikely(fault & VM_FAULT_MAJOR))
- current->maj_flt++;
- else
- current->min_flt++;
if (fault & VM_FAULT_RETRY) {
flags |= FAULT_FLAG_TRIED;

--
2.26.2