[PATCH 03/26] mm/arc: Use general page fault accounting

Peter Xu
2020-06-19T16:08:58Z

retry happened.

Fix PERF_COUNT_SW_PAGE_FAULTS perf event manually for page fault retries, by
moving it before taking mmap_sem.

CC: Vineet Gupta <vgupta@synopsys.com>
CC: linux-snps-arc@lists.infradead.org
Signed-off-by: Peter Xu <peterx@redhat.com>
---
arch/arc/mm/fault.c | 18 +++---------------
1 file changed, 3 insertions(+), 15 deletions(-)

diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
index 34380139e7a2..68e6849cf086 100644
--- a/arch/arc/mm/fault.c
+++ b/arch/arc/mm/fault.c
@@ -106,6 +106,7 @@ void do_page_fault(unsigned long address, struct pt_regs *regs)
if (write)
flags |= FAULT_FLAG_WRITE;

+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
down_read(&mm->mmap_sem);

@@ -131,7 +132,7 @@ void do_page_fault(unsigned long address, struct pt_regs *regs)
goto bad_area;
}

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

/* Quick path to respond to signals */
if (fault_signal_pending(fault, regs)) {
@@ -156,22 +157,9 @@ void do_page_fault(unsigned long address, struct pt_regs *regs)
* Major/minor page fault accounting
* (in case of retry we only land here once)
*/
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
-
- if (likely(!(fault & VM_FAULT_ERROR))) {
- if (fault & VM_FAULT_MAJOR) {
- tsk->maj_flt++;
- 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);
- }
-
+ if (likely(!(fault & VM_FAULT_ERROR)))
/* Normal return path: fault Handled Gracefully */
return;
- }

if (!user_mode(regs))
goto no_context;
--
2.26.2