diff mbox series

[143/165] mm/arc: use general page fault accounting

Message ID 20200812013752.LkqQfvZHO%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [001/165] percpu: return number of released bytes from pcpu_free_area() | expand

Commit Message

Andrew Morton Aug. 12, 2020, 1:37 a.m. UTC 
From: Peter Xu <peterx@redhat.com>
Subject: mm/arc: use general page fault accounting

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.

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

Link: http://lkml.kernel.org/r/20200707225021.200906-4-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/arc/mm/fault.c |   18 +++---------------
 1 file changed, 3 insertions(+), 15 deletions(-)
diff mbox series

Patch

--- a/arch/arc/mm/fault.c~mm-arc-use-general-page-fault-accounting
+++ a/arch/arc/mm/fault.c
@@ -105,6 +105,7 @@  void do_page_fault(unsigned long address
 	if (write)
 		flags |= FAULT_FLAG_WRITE;
 
+	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
 retry:
 	mmap_read_lock(mm);
 
@@ -130,7 +131,7 @@  retry:
 		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)) {
@@ -155,22 +156,9 @@  bad_area:
 	 * 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;