Hello, First, I've tried to limit changes between a working build and a broken one. The current findings are that: CONFIG_KSM does not matter (the bug reproduces even without it) Both CONFIG_READ_ONLY_THP_FOR_FS and CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS are needed to reproduce the bug (or at least I haven't managed to reproduce it with any of them disabled so far). On Thu, Feb 20, 2020 at 3:25 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > This is a compound page ... Dennis, are you willing to apply this patch > https://lore.kernel.org/linux-mm/20200211001536.1027652-12-jhubbard@xxxxxxxxxx/ > and retest? It will give us more information about what's going on. Here's the new log. The patch was applied to 5.5.4 manually as it did not apply automatically. page:ffffd52adae60180 refcount:522 mapcount:0 mapping:00000000b5351a5d index:0x406 head:ffffd52adae60000 order:9 compound_mapcount:0 ext4_da_aops name:"cc1plus" flags: 0x8000000000000000() raw: 8000000000000000 ffffd52adae60001 dead000000000122 dead000000000400 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 head: 8000000000010095 ffffd52ade75e848 ffff93b3c624f020 ffff93b387d7daf0 head: 0000000000000400 0000000000000000 0000020affffffff ffff93b3bff56000 page dumped because: VM_BUG_ON_PAGE(page_to_pgoff(page) != offset) ------------[ cut here ]------------ kernel BUG at mm/filemap.c:2529! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 33773 Comm: cc1plus Not tainted 5.5.4-r1-bughunt #5 Hardware name: Gigabyte Technology Co., Ltd. Z97M-D3H/Z97M-D3H, BIOS F5 05/30/2014 RIP: 0010:filemap_fault+0x82e/0x9f0 Code: 47 20 f7 c2 00 00 01 00 0f 84 d2 f8 ff ff 41 0f b6 4f 51 48 d3 e0 e9 c5 f8 ff ff 48 c7 c6 a0 15 35 98 4c 89 ff e8 52 14 03 00 <0f> 0b 45 31 ed e9 58 f8 ff ff 49 8b 57 08 48 8d 42 ff 83 e2 01 49 RSP: 0000:ffff9d3b8c163cf8 EFLAGS: 00010286 RAX: 0000000000000042 RBX: ffff9d3b8c163e28 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000ffffffff RBP: 0000000000000206 R08: 00000000000003b1 R09: 0000000000000004 R10: 0000000000000000 R11: 0000000000000001 R12: ffff93b387d7daf0 R13: ffff93b36fcaf200 R14: ffff93b387d7d980 R15: ffffd52adae60180 FS: 00007feb915e4ac0(0000) GS:ffff93b3cfe00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000809350 CR3: 00000007ac748003 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? preempt_count_add+0x63/0x90 ? _raw_spin_lock+0xe/0x30 ? alloc_set_pte+0x4c6/0x7b0 ? call_function_single_interrupt+0xa/0x20 ? filemap_map_pages+0x298/0x3b0 ext4_filemap_fault+0x28/0x3a __do_fault+0x33/0xb0 __handle_mm_fault+0xda9/0x13e0 ? _raw_spin_unlock_irq+0x9/0x20 handle_mm_fault+0xb3/0x1e0 do_user_addr_fault+0x1de/0x440 page_fault+0x2f/0x40 RIP: 0033:0x606c20 Code: Bad RIP value. RSP: 002b:00007fff7a679d98 EFLAGS: 00010283 RAX: 000000000000000a RBX: 00007feb8e462540 RCX: 0000000000000001 RDX: 00007feb8e462540 RSI: 0000000006864625 RDI: 0000000000000000 RBP: 00007feb90cc4da8 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffef05 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000006864625 Modules linked in: x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass iTCO_wdt iTCO_vendor_support ppdev crct10dif_pclmul crc32c_intel ghash_clmulni_intel snd_hda_codec_realtek snd_hda_codec_generic pcspkr snd_hda_codec_hdmi i2c_i801 radeon snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hda_core r8169 snd_pcm ttm realtek snd_timer mei_me snd mei soundcore lpc_ich mfd_core parport_pc parport acpi_pad sch_fq_codel efivarfs ---[ end trace 33b86223ecc3d3ab ]--- RIP: 0010:filemap_fault+0x82e/0x9f0 Code: 47 20 f7 c2 00 00 01 00 0f 84 d2 f8 ff ff 41 0f b6 4f 51 48 d3 e0 e9 c5 f8 ff ff 48 c7 c6 a0 15 35 98 4c 89 ff e8 52 14 03 00 <0f> 0b 45 31 ed e9 58 f8 ff ff 49 8b 57 08 48 8d 42 ff 83 e2 01 49 RSP: 0000:ffff9d3b8c163cf8 EFLAGS: 00010286 RAX: 0000000000000042 RBX: ffff9d3b8c163e28 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000ffffffff RBP: 0000000000000206 R08: 00000000000003b1 R09: 0000000000000004 R10: 0000000000000000 R11: 0000000000000001 R12: ffff93b387d7daf0 R13: ffff93b36fcaf200 R14: ffff93b387d7d980 R15: ffffd52adae60180 FS: 00007feb915e4ac0(0000) GS:ffff93b3cfe00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000606bf6 CR3: 00000007ac748003 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
