[PATCH 18/25] mm/riscv: Use mm_fault_accounting()

[Peter Xu]

Use the new mm_fault_accounting() helper for page fault accounting.

Avoid doing page fault accounting multiple times if the page fault is retried.

CC: Paul Walmsley <paul.walms...@sifive.com>
CC: Palmer Dabbelt <pal...@dabbelt.com>
CC: Albert Ou <a...@eecs.berkeley.edu>
CC: linux-ri...@lists.infradead.org
Signed-off-by: Peter Xu <pet...@redhat.com>
---
 arch/riscv/mm/fault.c | 21 +++------------------
 1 file changed, 3 insertions(+), 18 deletions(-)

diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index be84e32adc4c..9262338614d1 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -30,7 +30,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
        struct vm_area_struct *vma;
        struct mm_struct *mm;
        unsigned long addr, cause;
-       unsigned int flags = FAULT_FLAG_DEFAULT;
+       unsigned int flags = FAULT_FLAG_DEFAULT, major = 0;
        int code = SEGV_MAPERR;
        vm_fault_t fault;
 
@@ -65,9 +65,6 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
 
        if (user_mode(regs))
                flags |= FAULT_FLAG_USER;
-
-       perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
-
 retry:
        down_read(&mm->mmap_sem);
        vma = find_vma(mm, addr);
@@ -111,6 +108,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
         * the fault.
         */
        fault = handle_mm_fault(vma, addr, flags);
+       major |= fault & VM_FAULT_MAJOR;
 
        /*
         * If we need to retry but a fatal signal is pending, handle the
@@ -128,21 +126,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
                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;
 
@@ -156,6 +140,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
        }
 
        up_read(&mm->mmap_sem);
+       mm_fault_accounting(tsk, regs, addr, major);
        return;
 
        /*
-- 
2.26.2