Re: Lockdep warning in iwl_pcie_rx_handle()

Jiri Kosina
2021-03-02T07:09:08Z

On Mon, 1 Mar 2021, Jiri Kosina wrote:

> I am getting the splat below with Linus' tree as of today (5.11-rc1,
> fe07bfda2fb). I haven't started to look into the code yet, but apparently
> this has been already reported by Heiner here:
>
> https://www.spinics.net/lists/linux-wireless/msg208353.html
>
> so before I start digging deep into it (the previous kernel this
> particular machine had is 5.9, so I'd rather avoid lenghty bisect for now
> in case someone has already looked into it and has ideas where the problem
> is), I thought I'd ask whether this has been root-caused elsewhere
> already.
>
> Thanks.

After reverting 25edc8f259c7106 ("iwlwifi: pcie: properly implement
NAPI"), I don't see the lockdep warning any more (*), so it seems to be
culprit (or at least related). CCing Johannes.

Leaving the original mail below for reference.

(*) I see the warning below instead; but let's focus on fixing the lockdep
reported issue in the first place, I guess. It might be that I'd need
to revert more things in order to get to a fully consistent state.

[ 23.488194] WARNING: CPU: 1 PID: 1139 at kernel/softirq.c:178 __local_bh_enable_ip+0xa5/0xf0
[ 23.488203] Modules linked in: tun ip6table_mangle ip6table_filter ip6_tables iptable_mangle xt_DSCP xt_tcpudp xt_conntrack nf_conntrack nf_defrag_ipv6 libcrc32c nf_defrag_ipv4 iptable_filter ip_tables x_tables algif_skcipher af_alg bnep dm_crypt hid_generic snd_usb_audio snd_usbmidi_lib snd_rawmidi uvcvideo videobuf2_vmalloc btusb videobuf2_memops btrtl btbcm videobuf2_v4l2 btintel videodev videobuf2_common bluetooth ecdh_generic ecc iwlmvm mac80211 snd_hda_codec_hdmi libarc4 intel_rapl_msr snd_hda_codec_realtek snd_soc_skl iTCO_wdt iTCO_vendor_support snd_soc_sst_ipc snd_hda_codec_generic snd_soc_sst_dsp snd_hda_ext_core snd_soc_acpi_intel_match snd_soc_acpi wmi_bmof snd_soc_core intel_rapl_common x86_pkg_temp_thermal usbhid intel_powerclamp snd_compress coretemp snd_hda_intel snd_intel_dspcfg kvm_intel snd_hda_codec iwlwifi snd_hwdep e1000e kvm snd_hda_core ptp irqbypass joydev pcspkr snd_pcm i2c_i801 pps_core cfg80211 i2c_smbus snd_timer mei_me mei thermal intel_pch_thermal
[ 23.488334] thinkpad_acpi wmi battery ledtrig_audio platform_profile snd ac soundcore rfkill tpm_crb tpm_tis tpm_tis_core tpm acpi_pad button nls_iso8859_1 nls_cp437 vfat fat dm_mod fuse rtsx_pci_sdmmc mmc_core crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel crypto_simd cryptd i915 i2c_algo_bit drm_kms_helper syscopyarea xhci_pci serio_raw sysfillrect sysimgblt fb_sys_fops xhci_hcd rtsx_pci usbcore drm video sg msr efivarfs
[ 23.488404] CPU: 1 PID: 1139 Comm: NetworkManager Not tainted 5.12.0-rc1-00004-gb4ded168af79 #7
[ 23.488408] Hardware name: LENOVO 20K5S22R00/20K5S22R00, BIOS R0IET38W (1.16 ) 05/31/2017
[ 23.488411] RIP: 0010:__local_bh_enable_ip+0xa5/0xf0
[ 23.488416] Code: f7 69 e8 ee 23 14 00 fb 66 0f 1f 44 00 00 65 8b 05 f0 f4 f7 69 85 c0 74 3f 48 83 c4 08 5b c3 65 8b 05 9b fe f7 69 85 c0 75 8e <0f> 0b eb 8a 48 89 3c 24 e8 4e 20 14 00 48 8b 3c 24 eb 91 e8 13 4e
[ 23.488420] RSP: 0018:ffffafd580b13298 EFLAGS: 00010046
[ 23.488424] RAX: 0000000000000000 RBX: 0000000000000201 RCX: 0000000000000000
[ 23.488426] RDX: 0000000000000003 RSI: 0000000000000201 RDI: ffffffffc1272389
[ 23.488429] RBP: ffff96517ae4c018 R08: 0000000000000001 R09: 0000000000000000
[ 23.488431] R10: ffffafd580b13178 R11: 0000000000000001 R12: ffff96517b060000
[ 23.488433] R13: 0000000000000000 R14: ffffffff80000000 R15: 0000000000000001
[ 23.488436] FS: 00007fc604ebefc0(0000) GS:ffff965267480000(0000) knlGS:0000000000000000
[ 23.488439] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 23.488442] CR2: 000055fb3fef13b2 CR3: 0000000109112004 CR4: 00000000003706e0
[ 23.488444] Call Trace:
[ 23.488447] ? _raw_spin_unlock_bh+0x1f/0x30
[ 23.488453] iwl_pcie_enqueue_hcmd+0x5d9/0xa00 [iwlwifi]
[ 23.488499] iwl_trans_txq_send_hcmd+0x6c/0x430 [iwlwifi]
[ 23.488536] iwl_trans_send_cmd+0x88/0x170 [iwlwifi]
[ 23.488556] ? lock_acquire+0x277/0x3d0
[ 23.488564] iwl_mvm_send_cmd+0x32/0x80 [iwlmvm]
[ 23.488593] iwl_mvm_led_set+0xc2/0xe0 [iwlmvm]
[ 23.488629] ? led_trigger_event+0x46/0x70
[ 23.488633] led_trigger_event+0x46/0x70
[ 23.488643] ieee80211_do_open+0x5c5/0xa20 [mac80211]
[ 23.488719] ieee80211_open+0x67/0x90 [mac80211]
[ 23.488777] __dev_open+0xd4/0x150
[ 23.488790] __dev_change_flags+0x19e/0x1f0
[ 23.488805] dev_change_flags+0x23/0x60
[ 23.488813] do_setlink+0x30d/0x1230
[ 23.488829] ? lock_is_held_type+0xb4/0x120
[ 23.488841] ? __nla_validate_parse.part.7+0x57/0xcb0
[ 23.488855] ? __lock_acquire+0x2e1/0x1a50
[ 23.488870] __rtnl_newlink+0x560/0x910
[ 23.488890] ? __lock_acquire+0x2e1/0x1a50
[ 23.488893] ? __lock_acquire+0x2e1/0x1a50
[ 23.488915] ? lock_acquire+0x277/0x3d0
[ 23.488919] ? sock_def_readable+0x5/0x290
[ 23.488923] ? lock_is_held_type+0xb4/0x120
[ 23.488931] ? find_held_lock+0x2d/0x90
[ 23.488938] ? sock_def_readable+0xb3/0x290
[ 23.488944] ? lock_release+0x166/0x2a0
[ 23.489017] ? lock_is_held_type+0x90/0x120
[ 23.489037] rtnl_newlink+0x47/0x70
[ 23.489047] rtnetlink_rcv_msg+0x25c/0x470
[ 23.489057] ? netlink_deliver_tap+0x97/0x3e0
[ 23.489063] ? validate_linkmsg+0x350/0x350
[ 23.489072] netlink_rcv_skb+0x50/0x100
[ 23.489089] netlink_unicast+0x1b2/0x280
[ 23.489100] netlink_sendmsg+0x336/0x450
[ 23.489120] sock_sendmsg+0x5b/0x60
[ 23.489127] ____sys_sendmsg+0x1ed/0x250
[ 23.489131] ? copy_msghdr_from_user+0x5c/0x90
[ 23.489149] ___sys_sendmsg+0x88/0xd0
[ 23.489165] ? lock_is_held_type+0xb4/0x120
[ 23.489172] ? find_held_lock+0x2d/0x90
[ 23.489182] ? lock_release+0x166/0x2a0
[ 23.489194] ? __fget_files+0xfe/0x1d0
[ 23.489209] ? __sys_sendmsg+0x5e/0xa0
[ 23.489212] __sys_sendmsg+0x5e/0xa0
[ 23.489226] ? lockdep_hardirqs_on_prepare+0xd9/0x170
[ 23.489237] do_syscall_64+0x33/0x80
[ 23.489243] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 23.489247] RIP: 0033:0x7fc605c9572d
[ 23.489251] Code: 28 89 54 24 1c 48 89 74 24 10 89 7c 24 08 e8 da ee ff ff 8b 54 24 1c 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 33 44 89 c7 48 89 44 24 08 e8 2e ef ff ff 48
[ 23.489255] RSP: 002b:00007fffc83789f0 EFLAGS: 00000293 ORIG_RAX: 000000000000002e
[ 23.489259] RAX: ffffffffffffffda RBX: 000055ef468570c0 RCX: 00007fc605c9572d
[ 23.489261] RDX: 0000000000000000 RSI: 00007fffc8378a30 RDI: 000000000000000c
[ 23.489263] RBP: 0000000000000010 R08: 0000000000000000 R09: 0000000000000000
[ 23.489265] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
[ 23.489267] R13: 00007fffc8378b80 R14: 00007fffc8378b7c R15: 0000000000000000
[ 23.489295] irq event stamp: 170785
[ 23.489297] hardirqs last enabled at (170783): [<ffffffff9609a8c2>] __local_bh_enable_ip+0x82/0xf0
[ 23.489303] hardirqs last disabled at (170784): [<ffffffff96a8613d>] _raw_read_lock_irqsave+0x8d/0x90
[ 23.489307] softirqs last enabled at (170782): [<ffffffffc1272389>] iwl_pcie_enqueue_hcmd+0x5d9/0xa00 [iwlwifi]
[ 23.489328] softirqs last disabled at (170785): [<ffffffffc1271ec6>] iwl_pcie_enqueue_hcmd+0x116/0xa00 [iwlwifi]

>
>
>
>
> [ 9.970414] ========================================================
> [ 9.973157] WARNING: possible irq lock inversion dependency detected
> [ 9.976186] 5.12.0-rc1-00002-gbada49429032 #5 Not tainted
> [ 9.979239] --------------------------------------------------------
> [ 9.982223] irq/136-iwlwifi/565 just changed the state of lock:
> [ 9.984904] ffff89f28433b0b0 (&rxq->lock){+.-.}-{2:2}, at: iwl_pcie_rx_handle+0x7f/0x960 [iwlwifi]
> [ 9.987932] but this lock took another, SOFTIRQ-unsafe lock in the past:
> [ 9.990980] (napi_hash_lock){+.+.}-{2:2}
> [ 9.990986]
>
> and interrupts could create inverse lock ordering between them.
>
> [ 10.003955]
> other info that might help us debug this:
> [ 10.008989] Possible interrupt unsafe locking scenario:
>
> [ 10.013966] CPU0 CPU1
> [ 10.016404] ---- ----
> [ 10.018976] lock(napi_hash_lock);
> [ 10.021529] local_irq_disable();
> [ 10.023985] lock(&rxq->lock);
> [ 10.026340] lock(napi_hash_lock);
> [ 10.028644] <Interrupt>
> [ 10.030934] lock(&rxq->lock);
> [ 10.033119]
> *** DEADLOCK ***
>
> [ 10.039456] 1 lock held by irq/136-iwlwifi/565:
> [ 10.041549] #0: ffff89f2b1440170 (sync_cmd_lockdep_map){+.+.}-{0:0}, at: iwl_pcie_irq_handler+0x5/0xb30 [iwlwifi]
> [ 10.043728]
> the shortest dependencies between 2nd lock and 1st lock:
> [ 10.047836] -> (napi_hash_lock){+.+.}-{2:2} {
> [ 10.049845] HARDIRQ-ON-W at:
> [ 10.051860] lock_acquire+0x277/0x3d0
> [ 10.053881] _raw_spin_lock+0x2c/0x40
> [ 10.056170] netif_napi_add+0x14b/0x270
> [ 10.058349] e1000_probe+0x2fe/0xee0 [e1000e]
> [ 10.060539] local_pci_probe+0x42/0x90
> [ 10.062609] pci_device_probe+0x10b/0x1c0
> [ 10.064579] really_probe+0xef/0x4b0
> [ 10.066578] driver_probe_device+0xde/0x150
> [ 10.068765] device_driver_attach+0x4f/0x60
> [ 10.070890] __driver_attach+0x9c/0x140
> [ 10.073115] bus_for_each_dev+0x79/0xc0
> [ 10.075304] bus_add_driver+0x18d/0x220
> [ 10.077464] driver_register+0x5b/0xf0
> [ 10.079615] do_one_initcall+0x5b/0x300
> [ 10.081686] do_init_module+0x5b/0x21c
> [ 10.083730] load_module+0x1dae/0x22c0
> [ 10.085751] __do_sys_finit_module+0xad/0x110
> [ 10.087799] do_syscall_64+0x33/0x80
> [ 10.089758] entry_SYSCALL_64_after_hwframe+0x44/0xae
> [ 10.091747] SOFTIRQ-ON-W at:
> [ 10.093634] lock_acquire+0x277/0x3d0
> [ 10.095514] _raw_spin_lock+0x2c/0x40
> [ 10.097353] netif_napi_add+0x14b/0x270
> [ 10.099208] e1000_probe+0x2fe/0xee0 [e1000e]
> [ 10.101032] local_pci_probe+0x42/0x90
> [ 10.102835] pci_device_probe+0x10b/0x1c0
> [ 10.104648] really_probe+0xef/0x4b0
> [ 10.106439] driver_probe_device+0xde/0x150
> [ 10.106443] device_driver_attach+0x4f/0x60
> [ 10.106446] __driver_attach+0x9c/0x140
> [ 10.111451] bus_for_each_dev+0x79/0xc0
> [ 10.111454] bus_add_driver+0x18d/0x220
> [ 10.111456] driver_register+0x5b/0xf0
> [ 10.111459] do_one_initcall+0x5b/0x300
> [ 10.111462] do_init_module+0x5b/0x21c
> [ 10.111467] load_module+0x1dae/0x22c0
> [ 10.111469] __do_sys_finit_module+0xad/0x110
> [ 10.122761] do_syscall_64+0x33/0x80
> [ 10.122768] entry_SYSCALL_64_after_hwframe+0x44/0xae
> [ 10.122772] INITIAL USE at:
> [ 10.122775] lock_acquire+0x277/0x3d0
> [ 10.128672] _raw_spin_lock+0x2c/0x40
> [ 10.130160] netif_napi_add+0x14b/0x270
> [ 10.131725] e1000_probe+0x2fe/0xee0 [e1000e]
> [ 10.133268] local_pci_probe+0x42/0x90
> [ 10.134783] pci_device_probe+0x10b/0x1c0
> [ 10.136325] really_probe+0xef/0x4b0
> [ 10.137864] driver_probe_device+0xde/0x150
> [ 10.139394] device_driver_attach+0x4f/0x60
> [ 10.140908] __driver_attach+0x9c/0x140
> [ 10.142429] bus_for_each_dev+0x79/0xc0
> [ 10.143947] bus_add_driver+0x18d/0x220
> [ 10.145490] driver_register+0x5b/0xf0
> [ 10.147024] do_one_initcall+0x5b/0x300
> [ 10.148566] do_init_module+0x5b/0x21c
> [ 10.150013] load_module+0x1dae/0x22c0
> [ 10.151293] __do_sys_finit_module+0xad/0x110
> [ 10.152571] do_syscall_64+0x33/0x80
> [ 10.153740] entry_SYSCALL_64_after_hwframe+0x44/0xae
> [ 10.154889] }
> [ 10.156023] ... key at: [<ffffffffae84ef38>] napi_hash_lock+0x18/0x40
> [ 10.157191] ... acquired at:
> [ 10.158318] _raw_spin_lock+0x2c/0x40
> [ 10.159418] netif_napi_add+0x14b/0x270
> [ 10.160500] _iwl_pcie_rx_init+0x1f4/0x710 [iwlwifi]
> [ 10.161609] iwl_pcie_rx_init+0x1b/0x3b0 [iwlwifi]
> [ 10.162704] iwl_trans_pcie_start_fw+0x2ac/0x6a0 [iwlwifi]
> [ 10.163813] iwl_mvm_load_ucode_wait_alive+0x116/0x460 [iwlmvm]
> [ 10.164955] iwl_run_init_mvm_ucode+0xa4/0x3a0 [iwlmvm]
> [ 10.166079] iwl_op_mode_mvm_start+0x9ed/0xbf0 [iwlmvm]
> [ 10.167206] _iwl_op_mode_start.isra.4+0x42/0x80 [iwlwifi]
> [ 10.168326] iwl_opmode_register+0x71/0xe0 [iwlwifi]
> [ 10.169451] iwl_mvm_init+0x34/0x1000 [iwlmvm]
> [ 10.170585] do_one_initcall+0x5b/0x300
> [ 10.171699] do_init_module+0x5b/0x21c
> [ 10.172818] load_module+0x1dae/0x22c0
> [ 10.173933] __do_sys_finit_module+0xad/0x110
> [ 10.175048] do_syscall_64+0x33/0x80
> [ 10.176164] entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> [ 10.178421] -> (&rxq->lock){+.-.}-{2:2} {
> [ 10.179564] HARDIRQ-ON-W at:
> [ 10.180709] lock_acquire+0x277/0x3d0
> [ 10.181874] _raw_spin_lock_bh+0x34/0x40
> [ 10.183049] _iwl_pcie_rx_init+0x130/0x710 [iwlwifi]
> [ 10.184229] iwl_pcie_rx_init+0x1b/0x3b0 [iwlwifi]
> [ 10.185397] iwl_trans_pcie_start_fw+0x2ac/0x6a0 [iwlwifi]
> [ 10.186572] iwl_mvm_load_ucode_wait_alive+0x116/0x460 [iwlmvm]
> [ 10.187759] iwl_run_init_mvm_ucode+0xa4/0x3a0 [iwlmvm]
> [ 10.188950] iwl_op_mode_mvm_start+0x9ed/0xbf0 [iwlmvm]
> [ 10.190132] _iwl_op_mode_start.isra.4+0x42/0x80 [iwlwifi]
> [ 10.191312] iwl_opmode_register+0x71/0xe0 [iwlwifi]
> [ 10.192497] iwl_mvm_init+0x34/0x1000 [iwlmvm]
> [ 10.193685] do_one_initcall+0x5b/0x300
> [ 10.194868] do_init_module+0x5b/0x21c
> [ 10.196048] load_module+0x1dae/0x22c0
> [ 10.197225] __do_sys_finit_module+0xad/0x110
> [ 10.198409] do_syscall_64+0x33/0x80
> [ 10.199601] entry_SYSCALL_64_after_hwframe+0x44/0xae
> [ 10.200801] IN-SOFTIRQ-W at:
> [ 10.202000] lock_acquire+0x277/0x3d0
> [ 10.203202] _raw_spin_lock+0x2c/0x40
> [ 10.204412] iwl_pcie_rx_handle+0x7f/0x960 [iwlwifi]
> [ 10.205653] iwl_pcie_napi_poll+0x2c/0x100 [iwlwifi]
> [ 10.206879] __napi_poll+0x2d/0x220
> [ 10.208075] net_rx_action+0x106/0x280
> [ 10.209276] __do_softirq+0xd4/0x461
> [ 10.210486] do_softirq+0x63/0xa0
> [ 10.211677] __local_bh_enable_ip+0xd1/0xf0
> [ 10.212879] iwl_pcie_irq_handler+0x67d/0xb30 [iwlwifi]
> [ 10.214092] irq_thread_fn+0x21/0x60
> [ 10.215298] irq_thread+0x107/0x1a0
> [ 10.216491] kthread+0x13e/0x160
> [ 10.217670] ret_from_fork+0x22/0x30
> [ 10.218855] INITIAL USE at:
> [ 10.220030] lock_acquire+0x277/0x3d0
> [ 10.221239] _raw_spin_lock_bh+0x34/0x40
> [ 10.222438] _iwl_pcie_rx_init+0x130/0x710 [iwlwifi]
> [ 10.223667] iwl_pcie_rx_init+0x1b/0x3b0 [iwlwifi]
> [ 10.224894] iwl_trans_pcie_start_fw+0x2ac/0x6a0 [iwlwifi]
> [ 10.226167] iwl_mvm_load_ucode_wait_alive+0x116/0x460 [iwlmvm]
> [ 10.227448] iwl_run_init_mvm_ucode+0xa4/0x3a0 [iwlmvm]
> [ 10.228718] iwl_op_mode_mvm_start+0x9ed/0xbf0 [iwlmvm]
> [ 10.229977] _iwl_op_mode_start.isra.4+0x42/0x80 [iwlwifi]
> [ 10.231236] iwl_opmode_register+0x71/0xe0 [iwlwifi]
> [ 10.232492] iwl_mvm_init+0x34/0x1000 [iwlmvm]
> [ 10.233758] do_one_initcall+0x5b/0x300
> [ 10.235002] do_init_module+0x5b/0x21c
> [ 10.236224] load_module+0x1dae/0x22c0
> [ 10.237454] __do_sys_finit_module+0xad/0x110
> [ 10.238679] do_syscall_64+0x33/0x80
> [ 10.239906] entry_SYSCALL_64_after_hwframe+0x44/0xae
> [ 10.241137] }
> [ 10.242327] ... key at: [<ffffffffc111f0c0>] __key.69825+0x0/0xfffffffffffe2f40 [iwlwifi]
> [ 10.243587] ... acquired at:
> [ 10.244814] __lock_acquire+0x27d/0x1a50
> [ 10.246055] lock_acquire+0x277/0x3d0
> [ 10.247296] _raw_spin_lock+0x2c/0x40
> [ 10.248518] iwl_pcie_rx_handle+0x7f/0x960 [iwlwifi]
> [ 10.249789] iwl_pcie_napi_poll+0x2c/0x100 [iwlwifi]
> [ 10.251028] __napi_poll+0x2d/0x220
> [ 10.252254] net_rx_action+0x106/0x280
> [ 10.253484] __do_softirq+0xd4/0x461
> [ 10.254731] do_softirq+0x63/0xa0
> [ 10.255946] __local_bh_enable_ip+0xd1/0xf0
> [ 10.257157] iwl_pcie_irq_handler+0x67d/0xb30 [iwlwifi]
> [ 10.258382] irq_thread_fn+0x21/0x60
> [ 10.259608] irq_thread+0x107/0x1a0
> [ 10.260819] kthread+0x13e/0x160
> [ 10.262022] ret_from_fork+0x22/0x30
>
> [ 10.264433]
> stack backtrace:
> [ 10.266755] CPU: 2 PID: 565 Comm: irq/136-iwlwifi Not tainted 5.12.0-rc1-00002-gbada49429032 #5
> [ 10.267964] Hardware name: LENOVO 20K5S22R00/20K5S22R00, BIOS R0IET38W (1.16 ) 05/31/2017
> [ 10.269175] Call Trace:
> [ 10.270376] <IRQ>
> [ 10.271566] dump_stack+0x7f/0xa1
> [ 10.272750] mark_lock.part.49+0x8cb/0xc70
> [ 10.273950] ? __lock_acquire+0x2e1/0x1a50
> [ 10.275164] ? __lock_acquire+0x27d/0x1a50
> [ 10.276372] __lock_acquire+0x27d/0x1a50
> [ 10.277562] ? __lock_acquire+0x2e1/0x1a50
> [ 10.278754] ? __lock_acquire+0x2e1/0x1a50
> [ 10.279937] lock_acquire+0x277/0x3d0
> [ 10.281110] ? iwl_pcie_rx_handle+0x7f/0x960 [iwlwifi]
> [ 10.282317] ? lock_is_held_type+0xb4/0x120
> [ 10.283483] _raw_spin_lock+0x2c/0x40
> [ 10.284637] ? iwl_pcie_rx_handle+0x7f/0x960 [iwlwifi]
> [ 10.285813] iwl_pcie_rx_handle+0x7f/0x960 [iwlwifi]
> [ 10.286985] ? __lock_acquire+0x2e1/0x1a50
> [ 10.288148] ? try_to_wake_up+0x41c/0x600
> [ 10.289323] ? print_dl_rq+0xcc/0x160
> [ 10.290490] iwl_pcie_napi_poll+0x2c/0x100 [iwlwifi]
> [ 10.291684] __napi_poll+0x2d/0x220
> [ 10.292862] net_rx_action+0x106/0x280
> [ 10.294034] __do_softirq+0xd4/0x461
> [ 10.295185] do_softirq+0x63/0xa0
> [ 10.296349] </IRQ>
> [ 10.297514] __local_bh_enable_ip+0xd1/0xf0
> [ 10.298683] ? iwl_pcie_irq_handler+0x66c/0xb30 [iwlwifi]
> [ 10.299882] iwl_pcie_irq_handler+0x67d/0xb30 [iwlwifi]
> [ 10.301076] ? irq_forced_thread_fn+0x80/0x80
> [ 10.302265] irq_thread_fn+0x21/0x60
> [ 10.303434] ? irq_thread+0xa1/0x1a0
> [ 10.304596] irq_thread+0x107/0x1a0
> [ 10.305766] ? wake_threads_waitq+0x30/0x30
> [ 10.306922] ? irq_thread_dtor+0xa0/0xa0
> [ 10.308078] kthread+0x13e/0x160
> [ 10.309246] ? kthread_create_worker_on_cpu+0x70/0x70
> [ 10.310410] ret_from_fork+0x22/0x30
>

--
Jiri Kosina
SUSE Labs