[PATCH 13/26] mm/nios2: Use general page fault accounting

Peter Xu
2020-06-19T16:15:49Z

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: Ley Foon Tan <ley.foon.tan@intel.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
arch/nios2/mm/fault.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/arch/nios2/mm/fault.c b/arch/nios2/mm/fault.c
index 88abf297c759..823e7d0a9e97 100644
--- a/arch/nios2/mm/fault.c
+++ b/arch/nios2/mm/fault.c
@@ -24,6 +24,7 @@
#include <linux/mm.h>
#include <linux/extable.h>
#include <linux/uaccess.h>
+#include <linux/perf_event.h>

#include <asm/mmu_context.h>
#include <asm/traps.h>
@@ -83,6 +84,8 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause,
if (user_mode(regs))
flags |= FAULT_FLAG_USER;

+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
+
if (!down_read_trylock(&mm->mmap_sem)) {
if (!user_mode(regs) && !search_exception_tables(regs->ea))
goto bad_area_nosemaphore;
@@ -131,7 +134,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause,
* 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;
@@ -146,16 +149,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause,
BUG();
}

- /*
- * Major/minor page fault accounting is only done on the
- * initial attempt. If we go through a retry, it is extremely
- * likely that the page will be found in page cache at that point.
- */
if (flags & FAULT_FLAG_ALLOW_RETRY) {
- if (fault & VM_FAULT_MAJOR)
- current->maj_flt++;
- else
- current->min_flt++;
if (fault & VM_FAULT_RETRY) {
flags |= FAULT_FLAG_TRIED;

--
2.26.2