linux-kernel - [PATCH 25/25] mm/xtensa: Use mm_fault

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Date:   Mon, 15 Jun 2020 18:23:28 -0400
From:   Peter Xu <peterx@...hat.com>
To:     linux-kernel@...r.kernel.org
Cc:     Peter Xu <peterx@...hat.com>,
        Gerald Schaefer <gerald.schaefer@...ibm.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Andrea Arcangeli <aarcange@...hat.com>,
        Chris Zankel <chris@...kel.net>,
        Max Filippov <jcmvbkbc@...il.com>,
        linux-xtensa@...ux-xtensa.org
Subject: [PATCH 25/25] mm/xtensa: Use mm_fault_accounting()

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: Chris Zankel <chris@...kel.net>
CC: Max Filippov <jcmvbkbc@...il.com>
CC: linux-xtensa@...ux-xtensa.org
Signed-off-by: Peter Xu <peterx@...hat.com>
---
 arch/xtensa/mm/fault.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/arch/xtensa/mm/fault.c b/arch/xtensa/mm/fault.c
index e7172bd53ced..511a2c5f9857 100644
--- a/arch/xtensa/mm/fault.c
+++ b/arch/xtensa/mm/fault.c
@@ -42,7 +42,7 @@ void do_page_fault(struct pt_regs *regs)
 	int code;
 
 	int is_write, is_exec;
-	vm_fault_t fault;
+	vm_fault_t fault, major = 0;
 	unsigned int flags = FAULT_FLAG_DEFAULT;
 
 	code = SEGV_MAPERR;
@@ -109,6 +109,7 @@ void do_page_fault(struct pt_regs *regs)
 	 * the fault.
 	 */
 	fault = handle_mm_fault(vma, address, flags);
+	major |= fault & VM_FAULT_MAJOR;
 
 	if (fault_signal_pending(fault, regs))
 		return;
@@ -123,10 +124,6 @@ void do_page_fault(struct pt_regs *regs)
 		BUG();
 	}
 	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;
 
@@ -140,12 +137,7 @@ void do_page_fault(struct pt_regs *regs)
 	}
 
 	up_read(&mm->mmap_sem);
-	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
-	if (flags & VM_FAULT_MAJOR)
-		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, address);
-	else
-		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, address);
-
+	mm_fault_accounting(current, regs, address, major);
 	return;
 
 	/* Something tried to access memory that isn't in our memory map..
-- 
2.26.2