mm/ia64: 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>
Cc: "Luck, Tony" <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20200707225021.200906-9-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index abf2808..cd9766d 100644 (file)
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -14,6 +14,7 @@
 #include <linux/kdebug.h>
 #include <linux/prefetch.h>
 #include <linux/uaccess.h>
+#include <linux/perf_event.h>
 
 #include <asm/processor.h>
 #include <asm/exception.h>
@@ -105,6 +106,8 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
                flags |= FAULT_FLAG_USER;
        if (mask & VM_WRITE)
                flags |= FAULT_FLAG_WRITE;
+
+       perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
 retry:
        mmap_read_lock(mm);
 
@@ -143,7 +146,7 @@ retry:
         * sure we exit gracefully rather than endlessly redo 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;
@@ -166,10 +169,6 @@ retry:
        }
 
        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;