powerpc/mm: Don't lose "major" fault indication on retry
authorBenjamin Herrenschmidt <benh@kernel.crashing.org>
Wed, 19 Jul 2017 04:49:44 +0000 (14:49 +1000)
committerMichael Ellerman <mpe@ellerman.id.au>
Thu, 3 Aug 2017 06:06:51 +0000 (16:06 +1000)
If the first iteration returns VM_FAULT_MAJOR but the second
one doesn't, we fail to account the fault as a major fault.

This fixes it and brings the code in line with x86.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch/powerpc/mm/fault.c

index da54887a74e978ccb5d830a6d14bdfc812d3234f..e92448469d804b34e3c39591374be1eff6cba1e3 100644 (file)
@@ -349,7 +349,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
        int is_exec = TRAP(regs) == 0x400;
        int is_user = user_mode(regs);
        int is_write = page_fault_is_write(error_code);
-       int fault;
+       int fault, major = 0;
        int store_update_sp = 0;
 
 #ifdef CONFIG_PPC_ICSWX
@@ -501,6 +501,7 @@ good_area:
         * the fault.
         */
        fault = handle_mm_fault(vma, address, flags);
+       major |= fault & VM_FAULT_MAJOR;
 
        /*
         * Handle the retry right now, the mmap_sem has been released in that
@@ -534,7 +535,7 @@ good_area:
        /*
         * Major/minor page fault accounting.
         */
-       if (fault & VM_FAULT_MAJOR) {
+       if (major) {
                current->maj_flt++;
                perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, address);
                cmo_account_page_fault();