Log flooding with warning message when using linux-lowlatency kernel

[Franck]

In Vivid, when booting with lowlatency kernel (and possibly with generic kernel and threadirqs), Intel graphics driver will flood the logs with warning:

Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247652] ------------[ cut here ]------------
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247683] WARNING: CPU: 3 PID: 659 at /build/buildd/linux-3.19.0/drivers/gpu/drm/i915/intel_display.c:9705 intel_check_page_flip+0xa2/0xf0 [i915]()
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247685] WARN_ON(!in_irq())
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247686] Modules linked in: md4 nls_utf8 cifs fscache msr acpi_call(OE) xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 bridge stp llc ebtable_filter ebtables pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) binfmt_misc rfcomm bnep nls_iso8859_1 hid_apple intel_rapl iosf_mbi x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel uvcvideo kvm videobuf2_vmalloc videobuf2_memops crct10dif_pclmul i915 videobuf2_core crc32_pclmul ghash_clmulni_intel v4l2_common videodev aesni_intel media aes_x86_64 btusb lrw gf128mul glue_helper bluetooth ablk_helper cryptd arc4 snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic iwldvm dm_multipath scsi_dh snd_hda_intel mac80211 snd_hda_controller snd_hda_codec joydev snd_hwdep serio_raw drm_kms_helper iwlwifi snd_pcm thinkpad_acpi cfg80211 snd_seq_midi snd_seq_midi_event nvram snd_rawmidi snd_seq ip6t_REJECT nf_reject_ipv6 snd_seq_device nf_log_ipv6 lpc_ich snd_timer drm shpchp xt_hl snd mei_me nf_conntrack_ipv6 mei nf_defrag_ipv6 i2c_algo_bit ip6t_rt soundcore wmi video mac_hid ipt_REJECT nf_reject_ipv4 nf_log_ipv4 nf_log_common xt_LOG xt_multiport xt_limit xt_tcpudp nf_conntrack_ipv4 nf_defrag_ipv4 xt_addrtype xt_conntrack ip6table_filter ip6_tables nf_conntrack_netbios_ns nf_conntrack_broadcast cuse nf_nat_ftp nf_nat nf_conntrack_ftp parport_pc nf_conntrack ppdev iptable_filter ip_tables lp x_tables parport autofs4 btrfs xor raid6_pq hid_generic usbhid hid psmouse ahci e1000e sdhci_pci libahci sdhci ptp pps_core
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247768] CPU: 3 PID: 659 Comm: irq/32-i915 Tainted: G W OE 3.19.0-7-lowlatency #7-Ubuntu
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247770] Hardware name: LENOVO 2353CTO/2353CTO, BIOS G7ETA0WW (2.60 ) 05/14/2014
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247781] ffffffffc0be7010 ffff88042a353c98 ffffffff817c5402 ffff88043e2cfd78
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247784] ffff88042a353ce8 ffff88042a353cd8 ffffffff8107738a ffff88042a353cd8
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247786] ffff880428f3f000 ffff880428f5e800 0000000000000000 0000000000000000
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247788] Call Trace:
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247795] [<ffffffff817c5402>] dump_stack+0x4c/0x6e
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247805] [<ffffffff8107738a>] warn_slowpath_common+0x8a/0xc0
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247814] [<ffffffff81077406>] warn_slowpath_fmt+0x46/0x50
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247830] [<ffffffffc0b92482>] intel_check_page_flip+0xa2/0xf0 [i915]
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247843] [<ffffffffc0b5f4d8>] ironlake_irq_handler+0x428/0x1010 [i915]
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247847] [<ffffffff8109b55d>] ? finish_task_switch+0x5d/0x100
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247854] [<ffffffff810cfc60>] ? irq_thread_fn+0x50/0x50
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247858] [<ffffffff810cfc8d>] irq_forced_thread_fn+0x2d/0x70
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247861] [<ffffffff810d01af>] irq_thread+0x11f/0x150
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247865] [<ffffffff810cfd00>] ? wake_threads_waitq+0x30/0x30
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247868] [<ffffffff810d0090>] ? irq_thread_check_affinity+0x90/0x90
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247871] [<ffffffff81095bc9>] kthread+0xc9/0xe0
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247874] [<ffffffff81095b00>] ? kthread_create_on_node+0x1c0/0x1c0
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247877] [<ffffffff817cc33c>] ret_from_fork+0x7c/0xb0
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247880] [<ffffffff81095b00>] ? kthread_create_on_node+0x1c0/0x1c0
Mar 10 09:35:43 franck-ThinkPad-T430s kernel: [ 2216.247883] ---[ end trace fa4376848cde145f ]---

There seems to be a bug report here https://bugs.freedesktop.org/show_bug.cgi?id=89321

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: xserver-xorg-video-intel 2:2.99.917-1~exp1ubuntu2
ProcVersionSignature: Ubuntu 3.19.0-7.7-generic 3.19.0
Uname: Linux 3.19.0-7-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.16.2-0ubuntu2
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Tue Mar 10 10:46:28 2015
DistUpgraded: 2015-03-09 18:17:36,430 DEBUG enabling apt cron job
DistroCodename: vivid
DistroVariant: ubuntu
DkmsStatus:
 acpi-call, 1.1.0, 3.19.0-7-generic, x86_64: installed
 virtualbox, 4.3.24, 3.19.0-7-generic, x86_64: installed
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:21fb]
InstallationDate: Installed on 2014-12-13 (86 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
MachineType: LENOVO 2353CTO
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.19.0-7-generic.efi.signed root=/dev/mapper/ubuntu--vg-lv--root ro quiet splash nomdmonddf nomdmonisw vt.handoff=7
SourcePackage: xserver-xorg-video-intel
UpgradeStatus: Upgraded to vivid on 2015-03-09 (0 days ago)
dmi.bios.date: 05/14/2014
dmi.bios.vendor: LENOVO
dmi.bios.version: G7ETA0WW (2.60 )
dmi.board.asset.tag: Not Available
dmi.board.name: 2353CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Defined
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrG7ETA0WW(2.60):bd05/14/2014:svnLENOVO:pn2353CTO:pvrThinkPadT430s:rvnLENOVO:rn2353CTO:rvrNotDefined:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2353CTO
dmi.product.version: ThinkPad T430s
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.12.1+15.04.20150303-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.59-0ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.5.0-0ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.5.0-0ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.16.2.901-1ubuntu4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.0-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.4.0-2ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917-1~exp1ubuntu2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu2
xserver.bootTime: Tue Mar 10 10:09:26 2015
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 12876
 vendor SEC
xserver.version: 2:1.16.2.901-1ubuntu4

[SakariK (sakari-m-kapanen)]

Created attachment 113816
dmesg.log which shows the warnings

This has been discussed in http://lists.freedesktop.org/archives/intel-gfx/2015-February/059291.html , filing it here so it can be better tracked.

Beginning with kernel 3.19-rc1, there are warnings generated by the i915 from the function intel_check_page_flip. A dmesg log from boot to the problem with `drm.debug=13` is attached. This only happens when booting with threaded IRQs enabled by the `threadirqs` kernel flag.

As pointed out on the mailing lists, this is probably caused because in_irq() only tests for real hardware interrupts, not threaded ones. Further information here: http://lists.freedesktop.org/archives/intel-gfx/2015-February/059623.html

Kernel: 3.19-rc1
Distro: Arch Linux
Machine: Asus Zenbook UX32VD (Intel HD4000 graphics)

[Jani-nikula (jani-nikula)]

Fixed by

commit 6c51d46f135b00c00373fcd029786ccef2b02b5b
Author: Dave Gordon <email address hidden>
Date: Fri Mar 6 15:34:26 2015 +0000

    drm/i915: use in_interrupt() not in_irq() to check context

in drm-intel-fixes. Thanks for the report.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Gérard Bigot (gerard-bigot)]

I have this exact same problem. My computer logs :

 WARNING: CPU: 3 PID: 659 at /build/buildd/linux-3.19.0/drivers/gpu/drm/i915/intel_display.c:9705 intel_check_page_flip+0xa2/0xf0 [i915]()
WARN_ON(!in_irq())

continually with the 3.19.0-7 and 3.19.0-8 kernels in the -lowlatency kind.

It occurs sometime while resuming from pause in the -generic kind of kernel.

I concur : https://bugs.freedesktop.org/show_bug.cgi?id=89321 seems to have the answer. Even a patch there.

[Franck (alci)]

I'm not really entitled to make any suggestion, but One hundred papercuts / importance low seems a little bit understated to me: this is literally flooding the log, resulting in system slowdown, unusable logs and intense disk activity (bye SSDs).

[James Brierley (jmb8710)]

This is a kernel bug, rather than anything else. See http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=6c51d46f135b00c00373fcd029786ccef2b02b5b

A workaround is to boot with ‘nothreadirqs’ in the kernel command line.

[Franck (alci)]

Hope this can land in Vivid.
Not using thread irqs certainly works this bug around, but then playing audio on bluetooth is at best flaky !

[James Brierley (jmb8710)]

Yes, it isn’t ideal and sort of defeats the ‘low latency’ object, but it’s better than having your SSD thwacked (one of these writes to the log per second also adds up in terms of CPU activity).

As the patch is just a one-liner, which allows execution in both soft and hard interrupt contexts instead of hard only, and has been tested and pushed upstream (http://comments.gmane.org/gmane.comp.video.dri.devel/122993) I’d hope the kernel devs will be able to merge this in in time for Vivid.

[Franck (alci)]

It seems to be fixed as of version 2:2.99.917-1~exp1ubuntu2.1 of xserver-xorg-vieo-intel. I don't get the warnings anymore, be it with threadirqs parameter and generic kernel, or with lowlatency kernel.

[penalvch (penalvch)]

Franck, this bug report is being closed due to your last comment https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/1430230/comments/10 regarding this being fixed with an update. For future reference you can manage the status of your own bugs by clicking on the current status in the yellow line and then choosing a new status in the revealed drop down box. You can learn more about bug statuses at https://wiki.ubuntu.com/Bugs/Status. Thank you again for taking the time to report this bug and helping to make Ubuntu better. Please submit any future bugs you may find.

[Paul White (paulw2u)]

Closing as issue fixed