Received-SPF: pass (google.com: domain of linux-kernel+bounces-185499-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Precedence: bulk
MIME-Version: 1.0
References: <CABXGCsMB9A8-X+Np_Q+fWLURYL_0t3Y-MdoNabDM-Lzk58-DGA@mail.gmail.com>
 <Zk0HxVODITGKqYCw@x1n> <CABXGCsNbcMn0Z0RudFrBW78rZPE+cDY+f9r+yKf_AZwJZUOrQg@mail.gmail.com>
 <Zk0UA6wABOB9X_Dx@x1n>
In-Reply-To: <Zk0UA6wABOB9X_Dx@x1n>
From: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Date: Wed, 22 May 2024 03:21:04 +0500
Message-ID: <CABXGCsOZnxrSHd0y6QrFhzAiY-uTJiRSmo__C_P8Y2qjFV6bRA@mail.gmail.com>
Subject: Re: 6.10/bisected/regression - commit 8430557fc584 cause warning at
 mm/page_table_check.c:198 __page_table_check_ptes_set+0x306
To: Peter Xu <peterx@redhat.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>, axelrasmussen@google.com, 
	David Hildenbrand <david@redhat.com>, nadav.amit@gmail.com, 
	Andrew Morton <akpm@linux-foundation.org>, 
	Linux Memory Management List <linux-mm@kvack.org>, 
	Linux List Kernel Mailing <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Wed, May 22, 2024 at 2:37=E2=80=AFAM Peter Xu <peterx@redhat.com> wrote:
> Hmm I still cannot reproduce.  Weird.
>
> Would it be possible for you to identify which line in debug_vm_pgtable.c
> triggered that issue?
>
> I think it should be some set_pte_at() but I'm not sure, as there aren't =
a
> lot and all of them look benign so far.  It could be that I missed
> something important.

I hope it's helps:

> sh /usr/src/kernels/(uname -r)/scripts/faddr2line /lib/debug/lib/modules/=
(uname -r)/vmlinux debug_vm_pgtable+0x1c04
debug_vm_pgtable+0x1c04/0x3360:
native_ptep_get_and_clear at arch/x86/include/asm/pgtable_64.h:94
(inlined by) ptep_get_and_clear at arch/x86/include/asm/pgtable.h:1262
(inlined by) ptep_clear at include/linux/pgtable.h:509
(inlined by) pte_clear_tests at mm/debug_vm_pgtable.c:643
(inlined by) debug_vm_pgtable at mm/debug_vm_pgtable.c:1392

> cat -n /usr/src/debug/kernel-6.9-10323-g8f6a15f095a6/linux-6.10.0-0.rc0.2=
0240521git8f6a15f095a6.10.fc41.x86_64/mm/debug_vm_pgtable.c | sed -n '1387,=
1397 p'
  1387 * Page table modifying tests. They need to hold
  1388 * proper page table lock.
  1389 */
  1390
  1391 args.ptep =3D pte_offset_map_lock(args.mm, args.pmdp, args.vaddr, &p=
tl);
  1392 pte_clear_tests(&args);
  1393 pte_advanced_tests(&args);
  1394 if (args.ptep)
  1395 pte_unmap_unlock(args.ptep, ptl);
  1396
  1397 ptl =3D pmd_lock(args.mm, args.pmdp);

--=20
Best Regards,
Mike Gavrilov.