DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A41BE20772
From: Peter Xu <peterx@redhat.com>
To: linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
	peterx@redhat.com,
	John Hubbard <jhubbard@nvidia.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Gerald Schaefer <gerald.schaefer@de.ibm.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Will Deacon <will@kernel.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	linux-riscv@lists.infradead.org
Subject: [PATCH v4 17/26] mm/riscv: Use general page fault accounting
Date: Tue, 30 Jun 2020 16:45:45 -0400
Message-Id: <20200630204545.39293-1-peterx@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: quoted-printable
Sender: owner-linux-mm@kvack.org
Precedence: bulk

Use the general page fault accounting by passing regs into handle_mm_faul=
t().
It naturally solve the issue of multiple page fault accounting when page =
fault
retry happened.

CC: Paul Walmsley <paul.walmsley@sifive.com>
CC: Palmer Dabbelt <palmer@dabbelt.com>
CC: Albert Ou <aou@eecs.berkeley.edu>
CC: linux-riscv@lists.infradead.org
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 arch/riscv/mm/fault.c | 16 +---------------
 1 file changed, 1 insertion(+), 15 deletions(-)

diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 50a952a68433..e72cec09d55b 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -110,7 +110,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
 	 * make sure we exit gracefully rather than endlessly redo
 	 * the fault.
 	 */
-	fault =3D handle_mm_fault(vma, addr, flags, NULL);
+	fault =3D handle_mm_fault(vma, addr, flags, regs);
=20
 	/*
 	 * If we need to retry but a fatal signal is pending, handle the
@@ -128,21 +128,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
 		BUG();
 	}
=20
-	/*
-	 * 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 |=3D FAULT_FLAG_TRIED;
=20
--=20
2.26.2