mm/openrisc: 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.

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().

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Stafford Horne <shorne@gmail.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Link: http://lkml.kernel.org/r/20200707225021.200906-15-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c
index 3daa491..ca97d9b 100644 (file)
--- 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 @@ good_area:
         * 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 @@ good_area:
 
        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;