[PATCH v5 15/25] mm/parisc: Use general page fault accounting

From: Peter Xu
Date: Tue Jul 07 2020 - 18:51:49 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: James E.J. Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
CC: Helge Deller <deller@xxxxxx>
CC: linux-parisc@xxxxxxxxxxxxxxx
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
arch/parisc/mm/fault.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c
index e32d06928c24..4bfe2da9fbe3 100644
--- a/arch/parisc/mm/fault.c
+++ b/arch/parisc/mm/fault.c
@@ -18,6 +18,7 @@
#include <linux/extable.h>
#include <linux/uaccess.h>
#include <linux/hugetlb.h>
+#include <linux/perf_event.h>

#include <asm/traps.h>

@@ -281,6 +282,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long code,
acc_type = parisc_acctyp(code, regs->iir);
if (acc_type & VM_WRITE)
flags |= FAULT_FLAG_WRITE;
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
mmap_read_lock(mm);
vma = find_vma_prev(mm, address, &prev_vma);
@@ -302,7 +304,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long code,
* fault.
*/

- fault = handle_mm_fault(vma, address, flags, NULL);
+ fault = handle_mm_fault(vma, address, flags, regs);

if (fault_signal_pending(fault, regs))
return;
@@ -323,10 +325,6 @@ void do_page_fault(struct pt_regs *regs, unsigned long code,
BUG();
}
if (flags & FAULT_FLAG_ALLOW_RETRY) {
- if (fault & VM_FAULT_MAJOR)
- current->maj_flt++;
- else
- current->min_flt++;
if (fault & VM_FAULT_RETRY) {
/*
* No need to mmap_read_unlock(mm) as we would
--
2.26.2