(switched to email.  Please respond via emailed reply-to-all, not via the
bugzilla web interface).

On Tue, 01 Oct 2019 17:06:35 +0000 bugzilla-daemon@bugzilla.kernel.org wrote:

> https://bugzilla.kernel.org/show_bug.cgi?id=205065
> 
>             Bug ID: 205065
>            Summary: workqueue: PF_MEMALLOC task 173(kswapd0) is flushing
>                     !WQ_MEM_RECLAIM events:gen6_pm_rps_work [i915]
>            Product: Memory Management
>            Version: 2.5
>     Kernel Version: Ubuntu 5.3.0-13.14-generic 5.3.0
>           Hardware: All
>                 OS: Linux
>               Tree: Mainline
>             Status: NEW
>           Severity: normal
>           Priority: P1
>          Component: Other
>           Assignee: akpm@linux-foundation.org
>           Reporter: romanescu.2019@gmail.com
>         Regression: No

Maybe Tejun can help interpret this ;)

> Open bug in launchpad.net
> https://bugs.launchpad.net/bugs/1846241
> 
> dmesg:
> [ 9998.518472] ------------[ cut here ]------------
> [ 9998.518505] workqueue: PF_MEMALLOC task 173(kswapd0) is flushing
> !WQ_MEM_RECLAIM events:gen6_pm_rps_work [i915]
> [ 9998.518516] WARNING: CPU: 5 PID: 173 at kernel/workqueue.c:2598
> check_flush_dependency+0xa7/0x140
> [ 9998.518517] Modules linked in: usbhid rfcomm ccm cmac bnep
> snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio
> nls_iso8859_1 snd_soc_skl snd_soc_hdac_hda snd_hda_ext_core snd_soc_skl_ipc
> snd_soc_sst_ipc snd_soc_sst_dsp snd_soc_acpi_intel_match snd_soc_acpi
> snd_soc_core snd_compress ac97_bus snd_pcm_dmaengine x86_pkg_temp_thermal
> intel_powerclamp coretemp snd_hda_intel snd_hda_codec kvm_intel snd_hda_core
> kvm irqbypass snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event
> intel_rapl_msr
> snd_rawmidi ath9k_htc mei_hdcp ath9k_common btusb uvcvideo crct10dif_pclmul
> ath9k_hw btrtl videobuf2_vmalloc crc32_pclmul videobuf2_memops btbcm ath
> snd_seq btintel videobuf2_v4l2 i915 ghash_clmulni_intel mac80211
> videobuf2_common hid_sensor_incl_3d bluetooth hid_sensor_magn_3d
> hid_sensor_gyro_3d hid_sensor_accel_3d hid_sensor_rotation videodev
> snd_seq_device hid_sensor_trigger snd_timer cfg80211 drm_kms_helper mc
> industrialio_triggered_buffer ecdh_generic kfifo_buf ecc
> [ 9998.518560] processor_thermal_device hid_sensor_iio_common libarc4
> aesni_intel spi_pxa2xx_platform drm snd intel_rapl_common industrialio
> aes_x86_64 crypto_simd i2c_algo_bit fb_sys_fops input_leds cryptd glue_helper
> joydev dw_dmac intel_cstate syscopyarea sysfillrect
> intel_xhci_usb_role_switch
> mei_me intel_rapl_perf serio_raw wmi_bmof intel_wmi_thunderbolt dw_dmac_core
> soundcore idma64 8250_dw cros_ec_ishtp mei hid_multitouch roles virt_dma
> cros_ec_core sysimgblt intel_pch_thermal intel_soc_dts_iosf hp_wmi
> soc_button_array int3403_thermal intel_vbtn int340x_thermal_zone
> sparse_keymap
> hp_accel acpi_pad lis3lv02d hp_wireless input_polldev int3400_thermal
> acpi_thermal_rel mac_hid sch_fq_codel parport_pc ppdev sunrpc lp parport
> ip_tables x_tables autofs4 btrfs xor zstd_compress raid6_pq libcrc32c
> hid_sensor_custom hid_sensor_hub intel_ishtp_loader intel_ishtp_hid
> hid_generic
> psmouse sdhci_pci cqhci i2c_i801 ahci intel_lpss_pci intel_ish_ipc sdhci
> i2c_hid libahci intel_lpss intel_ishtp hid wmi
> [ 9998.518603] pinctrl_sunrisepoint video pinctrl_intel
> [ 9998.518609] CPU: 5 PID: 173 Comm: kswapd0 Not tainted 5.3.0-13-generic
> #14-Ubuntu
> [ 9998.518610] Hardware name: HP HP Pavilion x360 Convertible 14-cd0xxx/8486,
> BIOS F.34 04/29/2019
> [ 9998.518614] RIP: 0010:check_flush_dependency+0xa7/0x140
> [ 9998.518616] Code: 8d 8a 70 0a 00 00 4d 89 e0 48 8d 8b b0 00 00 00 4c 89 ca
> 48 c7 c7 e8 93 d3 a1 48 89 45 e0 c6 05 c4 29 75 01 01 e8 f4 13 fe ff <0f> 0b
> 48
> 8b 45 e0 eb 0f 4c 89 ef e8 39 8e 00 00 41 f6 45 25 08 75
> [ 9998.518618] RSP: 0018:ffffba44c034f7f0 EFLAGS: 00010086
> [ 9998.518620] RAX: 0000000000000000 RBX: ffff9d76a400ce00 RCX:
> 0000000000000000
> [ 9998.518621] RDX: 0000000000000063 RSI: ffffffffa2581fe3 RDI:
> 0000000000000046
> [ 9998.518623] RBP: ffffba44c034f810 R08: ffffffffa2581f80 R09:
> 0000000000000063
> [ 9998.518624] R10: ffffffffa2582360 R11: 00000000a2581fcb R12:
> ffffffffc1092710
> [ 9998.518625] R13: ffff9d76a30b5e00 R14: 0000000000000001 R15:
> ffff9d76a5df0700
> [ 9998.518627] FS: 0000000000000000(0000) GS:ffff9d76a5d40000(0000)
> knlGS:0000000000000000
> [ 9998.518628] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 9998.518630] CR2: 00007f877e503000 CR3: 000000019be0a002 CR4:
> 00000000003606e0
> [ 9998.518631] Call Trace:
> [ 9998.518636] __flush_work+0x97/0x1d0
> [ 9998.518641] ? enqueue_hrtimer+0x3d/0x90
> [ 9998.518644] __cancel_work_timer+0x10e/0x190
> [ 9998.518648] ? _cond_resched+0x19/0x30
> [ 9998.518651] ? synchronize_irq+0x3e/0xb0
> [ 9998.518654] cancel_work_sync+0x10/0x20
> [ 9998.518692] gen6_disable_rps_interrupts+0x95/0xc0 [i915]
> [ 9998.518732] gen6_rps_idle+0x1f/0xf0 [i915]
> [ 9998.518772] intel_gt_park+0x5b/0x60 [i915]
> [ 9998.518809] __intel_wakeref_put_last+0x1c/0x50 [i915]
> [ 9998.518843] intel_gt_pm_put+0x44/0x50 [i915]
> [ 9998.518877] __engine_park+0xc3/0xd0 [i915]
> [ 9998.518909] __intel_wakeref_put_last+0x1c/0x50 [i915]
> [ 9998.518943] intel_engine_pm_put+0x44/0x50 [i915]
> [ 9998.518977] intel_context_exit_engine+0x12/0x20 [i915]
> [ 9998.519015] i915_request_retire+0x1b2/0x370 [i915]
> [ 9998.519053] ring_retire_requests+0x53/0x60 [i915]
> [ 9998.519091] i915_retire_requests+0x49/0x90 [i915]
> [ 9998.519128] i915_gem_shrink+0xcb/0x4d0 [i915]
> [ 9998.519131] ? discard_new_inode+0x70/0x70
> [ 9998.519133] ? list_lru_walk_one+0x4f/0x80
> [ 9998.519135] ? prune_icache_sb+0x5c/0x80
> [ 9998.519172] i915_gem_shrinker_scan+0x64/0x120 [i915]
> [ 9998.519174] do_shrink_slab+0x150/0x2a0
> [ 9998.519176] ? shrink_node_memcg+0x2e5/0x370
> [ 9998.519178] shrink_slab+0xac/0x290
> [ 9998.519180] shrink_node+0xf4/0x490
> [ 9998.519183] balance_pgdat+0x319/0x590
> [ 9998.519186] kswapd+0x1ff/0x3c0
> [ 9998.519188] ? wait_woken+0x80/0x80
> [ 9998.519192] kthread+0x104/0x140
> [ 9998.519193] ? balance_pgdat+0x590/0x590
> [ 9998.519195] ? kthread_park+0x80/0x80
> [ 9998.519198] ret_from_fork+0x35/0x40
> [ 9998.519201] ---[ end trace 4fb7c7f43a69494a ]---
> 
> -- 
> You are receiving this mail because:
> You are the assignee for the bug.

+ Chris and Tvrtko

Quoting Andrew Morton (2019-10-03 00:57:21)
> 
> (switched to email.  Please respond via emailed reply-to-all, not via the
> bugzilla web interface).
> 
> On Tue, 01 Oct 2019 17:06:35 +0000 bugzilla-daemon@bugzilla.kernel.org wrote:
> 
> > https://bugzilla.kernel.org/show_bug.cgi?id=205065
> > 
> >             Bug ID: 205065
> >            Summary: workqueue: PF_MEMALLOC task 173(kswapd0) is flushing
> >                     !WQ_MEM_RECLAIM events:gen6_pm_rps_work [i915]
> >            Product: Memory Management
> >            Version: 2.5
> >     Kernel Version: Ubuntu 5.3.0-13.14-generic 5.3.0
> >           Hardware: All
> >                 OS: Linux
> >               Tree: Mainline
> >             Status: NEW
> >           Severity: normal
> >           Priority: P1
> >          Component: Other
> >           Assignee: akpm@linux-foundation.org
> >           Reporter: romanescu.2019@gmail.com
> >         Regression: No
> 
> Maybe Tejun can help interpret this ;)
> 
> > Open bug in launchpad.net
> > https://bugs.launchpad.net/bugs/1846241
> > 
> > dmesg:
> > [ 9998.518472] ------------[ cut here ]------------
> > [ 9998.518505] workqueue: PF_MEMALLOC task 173(kswapd0) is flushing
> > !WQ_MEM_RECLAIM events:gen6_pm_rps_work [i915]
> > [ 9998.518516] WARNING: CPU: 5 PID: 173 at kernel/workqueue.c:2598
> > check_flush_dependency+0xa7/0x140
> > [ 9998.518517] Modules linked in: usbhid rfcomm ccm cmac bnep
> > snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic
> ledtrig_audio
> > nls_iso8859_1 snd_soc_skl snd_soc_hdac_hda snd_hda_ext_core snd_soc_skl_ipc
> > snd_soc_sst_ipc snd_soc_sst_dsp snd_soc_acpi_intel_match snd_soc_acpi
> > snd_soc_core snd_compress ac97_bus snd_pcm_dmaengine x86_pkg_temp_thermal
> > intel_powerclamp coretemp snd_hda_intel snd_hda_codec kvm_intel
> snd_hda_core
> > kvm irqbypass snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event
> intel_rapl_msr
> > snd_rawmidi ath9k_htc mei_hdcp ath9k_common btusb uvcvideo crct10dif_pclmul
> > ath9k_hw btrtl videobuf2_vmalloc crc32_pclmul videobuf2_memops btbcm ath
> > snd_seq btintel videobuf2_v4l2 i915 ghash_clmulni_intel mac80211
> > videobuf2_common hid_sensor_incl_3d bluetooth hid_sensor_magn_3d
> > hid_sensor_gyro_3d hid_sensor_accel_3d hid_sensor_rotation videodev
> > snd_seq_device hid_sensor_trigger snd_timer cfg80211 drm_kms_helper mc
> > industrialio_triggered_buffer ecdh_generic kfifo_buf ecc
> > [ 9998.518560] processor_thermal_device hid_sensor_iio_common libarc4
> > aesni_intel spi_pxa2xx_platform drm snd intel_rapl_common industrialio
> > aes_x86_64 crypto_simd i2c_algo_bit fb_sys_fops input_leds cryptd
> glue_helper
> > joydev dw_dmac intel_cstate syscopyarea sysfillrect
> intel_xhci_usb_role_switch
> > mei_me intel_rapl_perf serio_raw wmi_bmof intel_wmi_thunderbolt
> dw_dmac_core
> > soundcore idma64 8250_dw cros_ec_ishtp mei hid_multitouch roles virt_dma
> > cros_ec_core sysimgblt intel_pch_thermal intel_soc_dts_iosf hp_wmi
> > soc_button_array int3403_thermal intel_vbtn int340x_thermal_zone
> sparse_keymap
> > hp_accel acpi_pad lis3lv02d hp_wireless input_polldev int3400_thermal
> > acpi_thermal_rel mac_hid sch_fq_codel parport_pc ppdev sunrpc lp parport
> > ip_tables x_tables autofs4 btrfs xor zstd_compress raid6_pq libcrc32c
> > hid_sensor_custom hid_sensor_hub intel_ishtp_loader intel_ishtp_hid
> hid_generic
> > psmouse sdhci_pci cqhci i2c_i801 ahci intel_lpss_pci intel_ish_ipc sdhci
> > i2c_hid libahci intel_lpss intel_ishtp hid wmi
> > [ 9998.518603] pinctrl_sunrisepoint video pinctrl_intel
> > [ 9998.518609] CPU: 5 PID: 173 Comm: kswapd0 Not tainted 5.3.0-13-generic
> > #14-Ubuntu
> > [ 9998.518610] Hardware name: HP HP Pavilion x360 Convertible
> 14-cd0xxx/8486,
> > BIOS F.34 04/29/2019
> > [ 9998.518614] RIP: 0010:check_flush_dependency+0xa7/0x140
> > [ 9998.518616] Code: 8d 8a 70 0a 00 00 4d 89 e0 48 8d 8b b0 00 00 00 4c 89
> ca
> > 48 c7 c7 e8 93 d3 a1 48 89 45 e0 c6 05 c4 29 75 01 01 e8 f4 13 fe ff <0f>
> 0b 48
> > 8b 45 e0 eb 0f 4c 89 ef e8 39 8e 00 00 41 f6 45 25 08 75
> > [ 9998.518618] RSP: 0018:ffffba44c034f7f0 EFLAGS: 00010086
> > [ 9998.518620] RAX: 0000000000000000 RBX: ffff9d76a400ce00 RCX:
> > 0000000000000000
> > [ 9998.518621] RDX: 0000000000000063 RSI: ffffffffa2581fe3 RDI:
> > 0000000000000046
> > [ 9998.518623] RBP: ffffba44c034f810 R08: ffffffffa2581f80 R09:
> > 0000000000000063
> > [ 9998.518624] R10: ffffffffa2582360 R11: 00000000a2581fcb R12:
> > ffffffffc1092710
> > [ 9998.518625] R13: ffff9d76a30b5e00 R14: 0000000000000001 R15:
> > ffff9d76a5df0700
> > [ 9998.518627] FS: 0000000000000000(0000) GS:ffff9d76a5d40000(0000)
> > knlGS:0000000000000000
> > [ 9998.518628] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [ 9998.518630] CR2: 00007f877e503000 CR3: 000000019be0a002 CR4:
> > 00000000003606e0
> > [ 9998.518631] Call Trace:
> > [ 9998.518636] __flush_work+0x97/0x1d0
> > [ 9998.518641] ? enqueue_hrtimer+0x3d/0x90
> > [ 9998.518644] __cancel_work_timer+0x10e/0x190
> > [ 9998.518648] ? _cond_resched+0x19/0x30
> > [ 9998.518651] ? synchronize_irq+0x3e/0xb0
> > [ 9998.518654] cancel_work_sync+0x10/0x20
> > [ 9998.518692] gen6_disable_rps_interrupts+0x95/0xc0 [i915]
> > [ 9998.518732] gen6_rps_idle+0x1f/0xf0 [i915]
> > [ 9998.518772] intel_gt_park+0x5b/0x60 [i915]
> > [ 9998.518809] __intel_wakeref_put_last+0x1c/0x50 [i915]
> > [ 9998.518843] intel_gt_pm_put+0x44/0x50 [i915]
> > [ 9998.518877] __engine_park+0xc3/0xd0 [i915]
> > [ 9998.518909] __intel_wakeref_put_last+0x1c/0x50 [i915]
> > [ 9998.518943] intel_engine_pm_put+0x44/0x50 [i915]
> > [ 9998.518977] intel_context_exit_engine+0x12/0x20 [i915]
> > [ 9998.519015] i915_request_retire+0x1b2/0x370 [i915]
> > [ 9998.519053] ring_retire_requests+0x53/0x60 [i915]
> > [ 9998.519091] i915_retire_requests+0x49/0x90 [i915]
> > [ 9998.519128] i915_gem_shrink+0xcb/0x4d0 [i915]
> > [ 9998.519131] ? discard_new_inode+0x70/0x70
> > [ 9998.519133] ? list_lru_walk_one+0x4f/0x80
> > [ 9998.519135] ? prune_icache_sb+0x5c/0x80
> > [ 9998.519172] i915_gem_shrinker_scan+0x64/0x120 [i915]
> > [ 9998.519174] do_shrink_slab+0x150/0x2a0
> > [ 9998.519176] ? shrink_node_memcg+0x2e5/0x370
> > [ 9998.519178] shrink_slab+0xac/0x290
> > [ 9998.519180] shrink_node+0xf4/0x490
> > [ 9998.519183] balance_pgdat+0x319/0x590
> > [ 9998.519186] kswapd+0x1ff/0x3c0
> > [ 9998.519188] ? wait_woken+0x80/0x80
> > [ 9998.519192] kthread+0x104/0x140
> > [ 9998.519193] ? balance_pgdat+0x590/0x590
> > [ 9998.519195] ? kthread_park+0x80/0x80
> > [ 9998.519198] ret_from_fork+0x35/0x40
> > [ 9998.519201] ---[ end trace 4fb7c7f43a69494a ]---
> > 
> > -- 
> > You are receiving this mail because:
> > You are the assignee for the bug.

Quoting Joonas Lahtinen (2019-10-03 00:28:43)
> + Chris and Tvrtko

It's a trivial warning, that's already fixed. In this case by separating
out the poweroff into process context.
c7302f204490 ("drm/i915: Defer final intel_wakeref_put to process context")
-Chris