mm/hexagon: 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: Brian Cain <bcain@codeaurora.org>
Link: http://lkml.kernel.org/r/20200707225021.200906-8-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/hexagon/mm/vm_fault.c b/arch/hexagon/mm/vm_fault.c
index f12f330..ef32c5a 100644 (file)
--- a/arch/hexagon/mm/vm_fault.c
+++ b/arch/hexagon/mm/vm_fault.c
@@ -18,6 +18,7 @@
 #include <linux/signal.h>
 #include <linux/extable.h>
 #include <linux/hardirq.h>
+#include <linux/perf_event.h>
 
 /*
  * Decode of hardware exception sends us to one of several
@@ -53,6 +54,8 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
 
        if (user_mode(regs))
                flags |= FAULT_FLAG_USER;
+
+       perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
 retry:
        mmap_read_lock(mm);
        vma = find_vma(mm, address);
@@ -88,7 +91,7 @@ good_area:
                break;
        }
 
-       fault = handle_mm_fault(vma, address, flags, NULL);
+       fault = handle_mm_fault(vma, address, flags, regs);
 
        if (fault_signal_pending(fault, regs))
                return;
@@ -96,10 +99,6 @@ good_area:
        /* The most common case -- we are done. */
        if (likely(!(fault & VM_FAULT_ERROR))) {
                if (flags & FAULT_FLAG_ALLOW_RETRY) {
-                       if (fault & VM_FAULT_MAJOR)
-                               current->maj_flt++;
-                       else
-                               current->min_flt++;
                        if (fault & VM_FAULT_RETRY) {
                                flags |= FAULT_FLAG_TRIED;
                                goto retry;