[PATCH v4 14/26] mm/openrisc: Use general page fault accounting

From: Peter Xu
Date: Tue Jun 30 2020 - 16:46:06 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: Jonas Bonn <jonas@xxxxxxxxxxxx>
CC: Stefan Kristiansson <stefan.kristiansson@xxxxxxxxxxxxx>
CC: Stafford Horne <shorne@xxxxxxxxx>
CC: openrisc@xxxxxxxxxxxxxxxxxxxx
Acked-by: Stafford Horne <shorne@xxxxxxxxx>
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
arch/openrisc/mm/fault.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c
index 3daa491d1edb..ca97d9baab51 100644
--- a/arch/openrisc/mm/fault.c
+++ b/arch/openrisc/mm/fault.c
@@ -15,6 +15,7 @@
#include <linux/interrupt.h>
#include <linux/extable.h>
#include <linux/sched/signal.h>
+#include <linux/perf_event.h>

#include <linux/uaccess.h>
#include <asm/siginfo.h>
@@ -103,6 +104,8 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address,
if (in_interrupt() || !mm)
goto no_context;

+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
+
retry:
mmap_read_lock(mm);
vma = find_vma(mm, address);
@@ -159,7 +162,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address,
* 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;
@@ -176,10 +179,6 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address,

if (flags & FAULT_FLAG_ALLOW_RETRY) {
/*RGD modeled on Cris */
- if (fault & VM_FAULT_MAJOR)
- tsk->maj_flt++;
- else
- tsk->min_flt++;
if (fault & VM_FAULT_RETRY) {
flags |= FAULT_FLAG_TRIED;

--
2.26.2