mm/riscv: 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.

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Link: http://lkml.kernel.org/r/20200707225021.200906-18-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 30c1124..716d64e 100644 (file)
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -109,7 +109,7 @@ good_area:
         * make sure we exit gracefully rather than endlessly redo
         * the fault.
         */
-       fault = handle_mm_fault(vma, addr, flags, NULL);
+       fault = handle_mm_fault(vma, addr, flags, regs);
 
        /*
         * If we need to retry but a fatal signal is pending, handle the
@@ -127,21 +127,7 @@ good_area:
                BUG();
        }
 
-       /*
-        * Major/minor page fault accounting is only done on the
-        * initial attempt. If we go through a retry, it is extremely
-        * likely that the page will be found in page cache at that point.
-        */
        if (flags & FAULT_FLAG_ALLOW_RETRY) {
-               if (fault & VM_FAULT_MAJOR) {
-                       tsk->maj_flt++;
-                       perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
-                                     1, regs, addr);
-               } else {
-                       tsk->min_flt++;
-                       perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
-                                     1, regs, addr);
-               }
                if (fault & VM_FAULT_RETRY) {
                        flags |= FAULT_FLAG_TRIED;