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[185.193.85.130]) by smtp.gmail.com with ESMTPSA id r44-v6sm10895908edd.87.2018.08.12.03.23.06 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 12 Aug 2018 03:23:07 -0700 (PDT) From: Pete Heist Content-Type: multipart/mixed; boundary="Apple-Mail=_C7C7017B-AFE7-4CAE-BA53-7C24B51874DE" Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) Date: Sun, 12 Aug 2018 12:23:05 +0200 References: To: Cake List In-Reply-To: Message-Id: X-Mailer: Apple Mail (2.3445.9.1) Subject: Re: [Cake] issue with Cake and bpf filter X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 12 Aug 2018 10:23:09 -0000 --Apple-Mail=_C7C7017B-AFE7-4CAE-BA53-7C24B51874DE Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii One more thing to add to this, when working with another bpf filter = which is relatively similar to this simple one (although has some more = innocuous looking code like map lookups and read-only operations on the = skb) sometimes the attached is suddenly and repeatedly sent to both = syslog and kern.log until the disk fills up... --Apple-Mail=_C7C7017B-AFE7-4CAE-BA53-7C24B51874DE Content-Disposition: attachment; filename=cake_loop.txt Content-Type: text/plain; x-unix-mode=0644; name="cake_loop.txt" Content-Transfer-Encoding: quoted-printable Aug 12 09:57:25 ubuntu kernel: [ 2408.152975] WARNING: CPU: 3 PID: 2304 = at /home/a/src/sch_cake/sch_cake.c:2094 cake_dequeue+0x791/0xc70 = [sch_cake] Aug 12 09:57:25 ubuntu kernel: [ 2408.152975] Modules linked in: = sch_cake(OE) nf_conntrack cls_bpf algif_hash af_alg binfmt_misc = vmw_balloon btusb btrtl btbcm btintel bluetooth uvcvideo joydev = input_leds videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 = videobuf2_core videodev media ecdh_generic intel_rapl_perf snd_ens1371 = serio_raw snd_ac97_codec gameport snd_rawmidi snd_seq_device ac97_bus = snd_pcm snd_timer snd soundcore shpchp mac_hid sch_fq_codel ib_iser = rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi = scsi_transport_iscsi vmw_vsock_vmci_transport vsock vmw_vmci ip_tables = x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov = async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 = raid0 multipath linear hid_generic usbhid hid crct10dif_pclmul = crc32_pclmul ghash_clmulni_intel pcbc aesni_intel Aug 12 09:57:25 ubuntu kernel: [ 2408.152997] aes_x86_64 crypto_simd = glue_helper cryptd vmwgfx ttm psmouse drm_kms_helper syscopyarea = sysfillrect sysimgblt e1000 fb_sys_fops ahci mptspi drm mptscsih libahci = mptbase scsi_transport_spi i2c_piix4 pata_acpi Aug 12 09:57:25 ubuntu kernel: [ 2408.153004] CPU: 3 PID: 2304 Comm: = sshd Tainted: G W OE 4.15.0-30-generic #32-Ubuntu Aug 12 09:57:25 ubuntu kernel: [ 2408.153004] Hardware name: VMware, = Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 = 05/19/2017 Aug 12 09:57:25 ubuntu kernel: [ 2408.153006] RIP: = 0010:cake_dequeue+0x791/0xc70 [sch_cake] Aug 12 09:57:25 ubuntu kernel: [ 2408.153006] RSP: 0018:ffffadf9c11df8a0 = EFLAGS: 00010282 Aug 12 09:57:25 ubuntu kernel: [ 2408.153007] RAX: 000000000000fffd RBX: = ffff94c0747331b0 RCX: 000000000000fffd Aug 12 09:57:25 ubuntu kernel: [ 2408.153008] RDX: 0000000000000000 RSI: = 000000000000fffd RDI: ffff94c1796df9b0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153008] RBP: ffffadf9c11df8f8 R08: = 0000000054bc4e6d R09: 0000000000000000 Aug 12 09:57:25 ubuntu kernel: [ 2408.153009] R10: 0000000000000000 R11: = 0000000000000001 R12: 00000227839cc5b1 Aug 12 09:57:25 ubuntu kernel: [ 2408.153009] R13: ffff94c0747331c0 R14: = ffff94c1718b0000 R15: 0000000000000000 Aug 12 09:57:25 ubuntu kernel: [ 2408.153010] FS: = 00007faa37446900(0000) GS:ffff94c1796c0000(0000) knlGS:0000000000000000 Aug 12 09:57:25 ubuntu kernel: [ 2408.153011] CS: 0010 DS: 0000 ES: = 0000 CR0: 0000000080050033 Aug 12 09:57:25 ubuntu kernel: [ 2408.153012] CR2: 00007fff85e71058 CR3: = 00000000b1436002 CR4: 00000000000606e0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153015] Call Trace: Aug 12 09:57:25 ubuntu kernel: [ 2408.153016] __qdisc_run+0x61/0x320 Aug 12 09:57:25 ubuntu kernel: [ 2408.153018] = __dev_queue_xmit+0x2ab/0x7d0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153019] dev_queue_xmit+0x10/0x20 Aug 12 09:57:25 ubuntu kernel: [ 2408.153021] ? = dev_queue_xmit+0x10/0x20 Aug 12 09:57:25 ubuntu kernel: [ 2408.153022] = ip_finish_output2+0x263/0x3c0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153024] = ip_finish_output+0x198/0x260 Aug 12 09:57:25 ubuntu kernel: [ 2408.153025] ? = ip_finish_output+0x198/0x260 Aug 12 09:57:25 ubuntu kernel: [ 2408.153027] ip_output+0x70/0xe0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153028] ip_local_out+0x3b/0x50 Aug 12 09:57:25 ubuntu kernel: [ 2408.153030] ip_queue_xmit+0x160/0x3e0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153031] ? = memcg_kmem_charge+0x7e/0xe0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153033] = tcp_transmit_skb+0x56a/0xa70 Aug 12 09:57:25 ubuntu kernel: [ 2408.153034] = tcp_write_xmit+0x1c7/0xf40 Aug 12 09:57:25 ubuntu kernel: [ 2408.153036] ? __alloc_skb+0x9b/0x1e0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153037] = __tcp_push_pending_frames+0x35/0xd0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153038] tcp_push+0xe4/0x110 Aug 12 09:57:25 ubuntu kernel: [ 2408.153039] = tcp_sendmsg_locked+0xb6e/0xe70 Aug 12 09:57:25 ubuntu kernel: [ 2408.153041] tcp_sendmsg+0x2c/0x50 Aug 12 09:57:25 ubuntu kernel: [ 2408.153042] inet_sendmsg+0x2e/0xb0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153043] sock_sendmsg+0x3e/0x50 Aug 12 09:57:25 ubuntu kernel: [ 2408.153045] sock_write_iter+0x8c/0xf0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153046] new_sync_write+0xe7/0x140 Aug 12 09:57:25 ubuntu kernel: [ 2408.153048] __vfs_write+0x29/0x40 Aug 12 09:57:25 ubuntu kernel: [ 2408.153050] vfs_write+0xb1/0x1a0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153051] SyS_write+0x55/0xc0 Aug 12 09:57:25 ubuntu kernel: [ 2408.153052] do_syscall_64+0x73/0x130 Aug 12 09:57:25 ubuntu kernel: [ 2408.153054] = entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Aug 12 09:57:25 ubuntu kernel: [ 2408.153054] RIP: 0033:0x7faa352a9154 Aug 12 09:57:25 ubuntu kernel: [ 2408.153055] RSP: 002b:00007fff85e75188 = EFLAGS: 00000246 ORIG_RAX: 0000000000000001 Aug 12 09:57:25 ubuntu kernel: [ 2408.153056] RAX: ffffffffffffffda RBX: = 000000000000006c RCX: 00007faa352a9154 Aug 12 09:57:25 ubuntu kernel: [ 2408.153056] RDX: 000000000000006c RSI: = 000055a21c87a290 RDI: 0000000000000003 Aug 12 09:57:25 ubuntu kernel: [ 2408.153057] RBP: 000055a21c87d560 R08: = 0000000000000000 R09: 0000000000000100 Aug 12 09:57:25 ubuntu kernel: [ 2408.153057] R10: 00007fff85e75100 R11: = 0000000000000246 R12: 0000000000000000 Aug 12 09:57:25 ubuntu kernel: [ 2408.153058] R13: 000055a21c866ad0 R14: = 0000000000000003 R15: 00007fff85e7520f Aug 12 09:57:25 ubuntu kernel: [ 2408.153059] Code: ff 80 fa 06 75 1b 48 = 63 55 a8 0f b7 c8 48 8d 14 52 0f b7 b4 93 0a 68 01 00 66 39 c6 0f 43 ce = 89 c8 66 3d 00 04 0f 86 70 fb ff ff <0f> 0b 41 8b 7d 10 85 ff 0f 8f 6e = fb ff ff 0f b7 c0 44 0f b7 bb=20 Aug 12 09:57:25 ubuntu kernel: [ 2408.153079] ---[ end trace = 9274605666353433 ]--- --Apple-Mail=_C7C7017B-AFE7-4CAE-BA53-7C24B51874DE Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On Aug 12, 2018, at 10:17 AM, Pete Heist wrote: >=20 > I=E2=80=99m seeing a panic (or infinite loop, not sure) when using = Cake (not fq_codel or sfq) with a simple bpf filter that just sets = skb->tc_classid to a fixed value. I haven=E2=80=99t investigated further = yet, but since I=E2=80=99m away from the computer more these days I = thought it better to post what I have so far in case someone wants to = look at it. >=20 > The attached contains the code and setup script I=E2=80=99m using and = a README.txt with instructions on how to reproduce it and some more = notes. Be prepared that it=E2=80=99s something I=E2=80=99m doing wrong. = :) However, I also probably shouldn=E2=80=99t be able to cause this to = happen this easily either, regardless of where the actual issue is... >=20 > Pete > --Apple-Mail=_C7C7017B-AFE7-4CAE-BA53-7C24B51874DE--