[11/26] mm/mips: Use general page fault accounting
diff mbox series

Message ID 20200619160538.8641-12-peterx@redhat.com
State New
Headers show
Series
  • mm: Page fault accounting cleanups
Related show

Commit Message

Peter Xu June 19, 2020, 4:05 p.m. UTC
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.

Fix PERF_COUNT_SW_PAGE_FAULTS perf event manually for page fault retries, by
moving it before taking mmap_sem.

CC: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
CC: linux-mips@vger.kernel.org
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 arch/mips/mm/fault.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

Comments

Thomas Bogendoerfer June 25, 2020, 8:28 a.m. UTC | #1
On Fri, Jun 19, 2020 at 12:05:23PM -0400, Peter Xu wrote:
> 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.
> 
> Fix PERF_COUNT_SW_PAGE_FAULTS perf event manually for page fault retries, by
> moving it before taking mmap_sem.
> 
> CC: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> CC: linux-mips@vger.kernel.org
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  arch/mips/mm/fault.c | 14 +++-----------
>  1 file changed, 3 insertions(+), 11 deletions(-)

Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Thomas.

Patch
diff mbox series

diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index 31c2afb8f8a5..750a4978a12b 100644
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -96,6 +96,8 @@  static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
 
 	if (user_mode(regs))
 		flags |= FAULT_FLAG_USER;
+
+	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
 retry:
 	down_read(&mm->mmap_sem);
 	vma = find_vma(mm, address);
@@ -152,12 +154,11 @@  static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
 	 * make 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;
 
-	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
 	if (unlikely(fault & VM_FAULT_ERROR)) {
 		if (fault & VM_FAULT_OOM)
 			goto out_of_memory;
@@ -168,15 +169,6 @@  static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
 		BUG();
 	}
 	if (flags & FAULT_FLAG_ALLOW_RETRY) {
-		if (fault & VM_FAULT_MAJOR) {
-			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
-						  regs, address);
-			tsk->maj_flt++;
-		} else {
-			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
-						  regs, address);
-			tsk->min_flt++;
-		}
 		if (fault & VM_FAULT_RETRY) {
 			flags |= FAULT_FLAG_TRIED;