[Moving to LKML]
Max sent in the following (best ever) bug report:
On Wed, Jul 24, 2013 at 8:41 AM, Max Hailperin <[email protected]> wrote:
> [1.] One line summary of the problem:
> Persistent unfair sharing of a processor by auto groups in 3.11-rc2 (has
> twice regressed)
>
> [2.] Full description of the problem/report:
> Although I've used bisection to figure out where this problem originated and
> have a one-line patch that fixes it, I don't understand the root cause and
> don't have any reason to think my patch is the right one.
>
> If I run a single processor-hogging loop in each of two terminal windows (so
> one task in each of two auto groups) and use schedtool to pin each of them
> on processor 0, they ought to each get 50% of that processor's time.
> However, a substantial fraction of my trials of this experiment (detailed in
> section 7 below) produce a different result: the two tasks get persistently
> stuck in some ratio other than 50/50. In the screenshot I have attached,
> they are running 55/45, but I have observed as extreme as 66/33. Whatever
> the ratio is, it remains fixed aside from minor fluctuations for as long as
> I let it run, which has been over an hour. This phenomenon doesn't show up
> if I boot with nosmp rather than using schedtool or if I disable auto
> grouping. The tasks really are getting disproportionate CPU rather than
> just looking that way due to some accounting malfunction; I've confirmed
> this by having each produce output every N iterations so that I can see they
> are running at different rates.
>
> Bisection reveals that this problem most recently was introduced by commit
> 17bc14b767cf0692420c43dbe5310ae98a5a7836 which reverted commit
> f269ae0469fc882332bdfb5db15d3c1315fe2a10 (sched: Update_cfs_shares at period
> edge). In between these two commits, I consistently get 50/50 sharing aside
> from small fluctuations.
>
> As suggested by the problem having been (re-) introduced by a revert, it was
> also present as of the parent commit of the reverted commit (that is, as of
> 48a1675323fa1b7844e479ad2a4469f4558c0f79). A second round of bisection
> looking backward from there identifies the problem as having initially been
> introduced in commit 82958366cfea1a50e7e90907b2d55ae29ed69974 (sched:
> Replace update_shares weight distribution with per-entity computation).
>
> I was able to make the problem go away by applying to 3.11-rc2 the one-line
> patch I have attached, which is a subset of the reverted commit.
>
> [3.] Keywords (i.e., modules, networking, kernel):
> sched
>
> [4.] Kernel information
> [4.1.] Kernel version (from /proc/version):
> Linux version 3.11.0-rc2 (max@max-st1-Inspiron-5423) (gcc version 4.7.3
> (Ubuntu/Linaro 4.7.3-1ubuntu1) ) #1 SMP Tue Jul 23 13:09:32 CDT 2013
>
> [4.2.] Kernel .config file:
> See the attached config file.
>
> [5.] Most recent kernel version which did not have the bug:
> See bisection information above.
>
> [6.] Output of Oops.. message (if applicable) with symbolic information
> resolved (see Documentation/oops-tracing.txt)
> N/A
>
> [7.] A small shell script or example program which triggers the
> problem (if possible)
> In each of two terminal windows give the command
> schedtool -a 0 -e bash -c 'while ((1)); do :; done'
> while in a third terminal window running top to observe the result. See the
> attached screenshot for an example. The results are not consistent, but in
> the buggy versions of the kernel, many of the attempts will show the tasks
> running in a non-50/50 ratio (persistently). It's never taken me more than a
> handful of tries to see the effect. Also, in the cases where the tasks are
> running in more or less 50/50, if I stop one with control-z and then restart
> it, sometimes that is enough to switch to disproportionate execution.
>
> [8.] Environment
> [8.1.] Software (add the output of the ver_linux script here)
> If some fields are empty or look unusual you may have an old version.
> Compare to the current minimal requirements in Documentation/Changes.
>
> Linux max-st1-Inspiron-5423 3.11.0-rc2 #1 SMP Tue Jul 23 13:09:32 CDT 2013
> x86_64 x86_64 x86_64 GNU/Linux
>
> Gnu C 4.7
> Gnu make 3.81
> binutils 2.23.2
> util-linux 2.20.1
> mount support
> module-init-tools 9
> e2fsprogs 1.42.5
> pcmciautils 018
> PPP 2.4.5
> Linux C Library 2.17
> Dynamic linker (ldd) 2.17
> Procps 3.3.3
> Net-tools 1.60
> Kbd 1.15.5
> Sh-utils 8.20
> wireless-tools 30
> Modules Loaded rfcomm parport_pc bnep ppdev arc4 iwldvm mac80211
> i915 snd_hda_codec_hdmi snd_hda_codec_idt snd_hda_intel snd_hda_codec
> iwlwifi drm_kms_helper drm uvcvideo btusb videobuf2_vmalloc videobuf2_memops
> snd_hwdep videobuf2_core bluetooth snd_pcm videodev joydev snd_page_alloc
> snd_seq_midi cfg80211 snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device
> snd_timer mei_me lp i2c_algo_bit psmouse snd mei video rts5139 dell_laptop
> dcdbas dell_wmi lpc_ich parport sparse_keymap mac_hid serio_raw soundcore
> wmi ahci libahci alx mdio
>
> [8.2.] Processor information (from /proc/cpuinfo):
> processor : 0
> vendor_id : GenuineIntel
> cpu family : 6
> model : 58
> model name : Intel(R) Core(TM) i3-3217U CPU @ 1.80GHz
> stepping : 9
> microcode : 0x15
> cpu MHz : 864.000
> cache size : 3072 KB
> physical id : 0
> siblings : 4
> core id : 0
> cpu cores : 2
> apicid : 0
> initial apicid : 0
> fpu : yes
> fpu_exception : yes
> cpuid level : 13
> wp : yes
> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat
> pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm
> constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc
> aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3
> cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer xsave avx
> f16c lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi
> flexpriority ept vpid fsgsbase smep erms
> bogomips : 3591.91
> clflush size : 64
> cache_alignment : 64
> address sizes : 36 bits physical, 48 bits virtual
> power management:
>
> processor : 1
> vendor_id : GenuineIntel
> cpu family : 6
> model : 58
> model name : Intel(R) Core(TM) i3-3217U CPU @ 1.80GHz
> stepping : 9
> microcode : 0x15
> cpu MHz : 990.000
> cache size : 3072 KB
> physical id : 0
> siblings : 4
> core id : 1
> cpu cores : 2
> apicid : 2
> initial apicid : 2
> fpu : yes
> fpu_exception : yes
> cpuid level : 13
> wp : yes
> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat
> pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm
> constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc
> aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3
> cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer xsave avx
> f16c lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi
> flexpriority ept vpid fsgsbase smep erms
> bogomips : 3591.91
> clflush size : 64
> cache_alignment : 64
> address sizes : 36 bits physical, 48 bits virtual
> power management:
>
> processor : 2
> vendor_id : GenuineIntel
> cpu family : 6
> model : 58
> model name : Intel(R) Core(TM) i3-3217U CPU @ 1.80GHz
> stepping : 9
> microcode : 0x15
> cpu MHz : 792.000
> cache size : 3072 KB
> physical id : 0
> siblings : 4
> core id : 0
> cpu cores : 2
> apicid : 1
> initial apicid : 1
> fpu : yes
> fpu_exception : yes
> cpuid level : 13
> wp : yes
> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat
> pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm
> constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc
> aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3
> cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer xsave avx
> f16c lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi
> flexpriority ept vpid fsgsbase smep erms
> bogomips : 3591.91
> clflush size : 64
> cache_alignment : 64
> address sizes : 36 bits physical, 48 bits virtual
> power management:
>
> processor : 3
> vendor_id : GenuineIntel
> cpu family : 6
> model : 58
> model name : Intel(R) Core(TM) i3-3217U CPU @ 1.80GHz
> stepping : 9
> microcode : 0x15
> cpu MHz : 1116.000
> cache size : 3072 KB
> physical id : 0
> siblings : 4
> core id : 1
> cpu cores : 2
> apicid : 3
> initial apicid : 3
> fpu : yes
> fpu_exception : yes
> cpuid level : 13
> wp : yes
> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat
> pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm
> constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc
> aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3
> cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer xsave avx
> f16c lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi
> flexpriority ept vpid fsgsbase smep erms
> bogomips : 3591.91
> clflush size : 64
> cache_alignment : 64
> address sizes : 36 bits physical, 48 bits virtual
> power management:
>
> [8.3.] Module information (from /proc/modules):
> rfcomm 42539 12 - Live 0x0000000000000000
> parport_pc 32688 0 - Live 0x0000000000000000
> bnep 18036 2 - Live 0x0000000000000000
> ppdev 12934 0 - Live 0x0000000000000000
> arc4 12615 2 - Live 0x0000000000000000
> iwldvm 241420 0 - Live 0x0000000000000000
> mac80211 601324 1 iwldvm, Live 0x0000000000000000
> i915 659650 3 - Live 0x0000000000000000
> snd_hda_codec_hdmi 41176 1 - Live 0x0000000000000000
> snd_hda_codec_idt 50389 1 - Live 0x0000000000000000
> snd_hda_intel 47930 3 - Live 0x0000000000000000
> snd_hda_codec 188542 3 snd_hda_codec_hdmi,snd_hda_codec_idt,snd_hda_intel,
> Live 0x0000000000000000
> iwlwifi 166005 1 iwldvm, Live 0x0000000000000000
> drm_kms_helper 52880 1 i915, Live 0x0000000000000000
> drm 292458 4 i915,drm_kms_helper, Live 0x0000000000000000
> uvcvideo 80784 0 - Live 0x0000000000000000
> btusb 22517 0 - Live 0x0000000000000000
> videobuf2_vmalloc 13056 1 uvcvideo, Live 0x0000000000000000
> videobuf2_memops 13202 1 videobuf2_vmalloc, Live 0x0000000000000000
> snd_hwdep 13602 1 snd_hda_codec, Live 0x0000000000000000
> videobuf2_core 40513 1 uvcvideo, Live 0x0000000000000000
> bluetooth 234284 22 rfcomm,bnep,btusb, Live 0x0000000000000000
> snd_pcm 101975 3 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec, Live
> 0x0000000000000000
> videodev 133456 2 uvcvideo,videobuf2_core, Live 0x0000000000000000
> joydev 17377 0 - Live 0x0000000000000000
> snd_page_alloc 18710 2 snd_hda_intel,snd_pcm, Live 0x0000000000000000
> snd_seq_midi 13324 0 - Live 0x0000000000000000
> cfg80211 488276 3 iwldvm,mac80211,iwlwifi, Live 0x0000000000000000
> snd_seq_midi_event 14899 1 snd_seq_midi, Live 0x0000000000000000
> snd_rawmidi 30180 1 snd_seq_midi, Live 0x0000000000000000
> snd_seq 65684 2 snd_seq_midi,snd_seq_midi_event, Live 0x0000000000000000
> snd_seq_device 14497 3 snd_seq_midi,snd_rawmidi,snd_seq, Live
> 0x0000000000000000
> snd_timer 29370 2 snd_pcm,snd_seq, Live 0x0000000000000000
> mei_me 13684 0 - Live 0x0000000000000000
> lp 17759 0 - Live 0x0000000000000000
> i2c_algo_bit 13413 1 i915, Live 0x0000000000000000
> psmouse 95952 0 - Live 0x0000000000000000
> snd 69134 17
> snd_hda_codec_hdmi,snd_hda_codec_idt,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_seq_midi,snd_rawmidi,snd_seq,snd_seq_device,snd_timer,
> Live 0x0000000000000000
> mei 54059 1 mei_me, Live 0x0000000000000000
> video 19327 1 i915, Live 0x0000000000000000
> rts5139 315256 0 - Live 0x0000000000000000 (C)
> dell_laptop 17369 0 - Live 0x0000000000000000
> dcdbas 14397 1 dell_laptop, Live 0x0000000000000000
> dell_wmi 12681 0 - Live 0x0000000000000000
> lpc_ich 21080 0 - Live 0x0000000000000000
> parport 42214 3 parport_pc,ppdev,lp, Live 0x0000000000000000
> sparse_keymap 13890 1 dell_wmi, Live 0x0000000000000000
> mac_hid 13205 0 - Live 0x0000000000000000
> serio_raw 13253 0 - Live 0x0000000000000000
> soundcore 12680 1 snd, Live 0x0000000000000000
> wmi 19070 1 dell_wmi, Live 0x0000000000000000
> ahci 29915 2 - Live 0x0000000000000000
> libahci 31885 1 ahci, Live 0x0000000000000000
> alx 32175 0 - Live 0x0000000000000000
> mdio 13807 1 alx, Live 0x0000000000000000
>
> [8.4.] Loaded driver and hardware information (/proc/ioports, /proc/iomem)
> 0000-0cf7 : PCI Bus 0000:00
> 0000-001f : dma1
> 0020-0021 : pic1
> 0040-0043 : timer0
> 0050-0053 : timer1
> 0060-0060 : keyboard
> 0064-0064 : keyboard
> 0070-0077 : rtc0
> 0080-008f : dma page reg
> 00a0-00a1 : pic2
> 00c0-00df : dma2
> 00f0-00ff : fpu
> 0400-0403 : ACPI PM1a_EVT_BLK
> 0404-0405 : ACPI PM1a_CNT_BLK
> 0408-040b : ACPI PM_TMR
> 0410-0415 : ACPI CPU throttle
> 0420-042f : ACPI GPE0_BLK
> 0430-0433 : iTCO_wdt
> 0450-0450 : ACPI PM2_CNT_BLK
> 0454-0457 : pnp 00:05
> 0458-047f : pnp 00:03
> 0460-047f : iTCO_wdt
> 04d0-04d1 : pnp 00:07
> 0500-057f : pnp 00:03
> 0680-069f : pnp 00:03
> 0cf8-0cff : PCI conf1
> 0d00-ffff : PCI Bus 0000:00
> 1000-100f : pnp 00:03
> 164e-164f : pnp 00:03
> e000-efff : PCI Bus 0000:09
> e000-e07f : 0000:09:00.0
> f000-f03f : 0000:00:02.0
> f040-f05f : 0000:00:1f.3
> f060-f07f : 0000:00:1f.2
> f060-f07f : ahci
> f080-f083 : 0000:00:1f.2
> f080-f083 : ahci
> f090-f097 : 0000:00:1f.2
> f090-f097 : ahci
> f0a0-f0a3 : 0000:00:1f.2
> f0a0-f0a3 : ahci
> f0b0-f0b7 : 0000:00:1f.2
> f0b0-f0b7 : ahci
> ffff-ffff : pnp 00:03
> ffff-ffff : pnp 00:03
>
> 00000000-00000fff : reserved
> 00001000-000917ff : System RAM
> 00091800-0009ffff : reserved
> 000a0000-000bffff : PCI Bus 0000:00
> 000c0000-000cedff : Video ROM
> 000cf000-000d97ff : Adapter ROM
> 000d9800-000da7ff : Adapter ROM
> 000dc000-000dffff : PCI Bus 0000:00
> 000e0000-000fffff : reserved
> 000e0000-000e3fff : PCI Bus 0000:00
> 000e4000-000e7fff : PCI Bus 0000:00
> 000f0000-000fffff : System ROM
> 00100000-1fffffff : System RAM
> 01000000-016fae8a : Kernel code
> 016fae8b-01d008bf : Kernel data
> 01e5a000-01fccfff : Kernel bss
> 20000000-201fffff : reserved
> 20000000-201fffff : pnp 00:0b
> 20200000-40003fff : System RAM
> 40004000-40004fff : reserved
> 40004000-40004fff : pnp 00:0b
> 40005000-d82c7fff : System RAM
> d82c8000-d8d1cfff : reserved
> d8d1d000-d8d2dfff : ACPI Tables
> d8d2e000-d9bb7fff : ACPI Non-volatile Storage
> d9bb8000-da582fff : reserved
> da583000-da583fff : System RAM
> da584000-da5c6fff : ACPI Non-volatile Storage
> da5c7000-da9d7fff : System RAM
> da9d8000-daff3fff : reserved
> daff4000-daffffff : System RAM
> db000000-db7fffff : RAM buffer
> db800000-df9fffff : reserved
> dfa00000-feafffff : PCI Bus 0000:00
> dfa00000-dfa00fff : pnp 00:0a
> e0000000-efffffff : 0000:00:02.0
> f7800000-f7bfffff : 0000:00:02.0
> f7c00000-f7cfffff : PCI Bus 0000:09
> f7c00000-f7c3ffff : 0000:09:00.0
> f7c00000-f7c3ffff : alx
> f7d00000-f7dfffff : PCI Bus 0000:07
> f7d00000-f7d01fff : 0000:07:00.0
> f7d00000-f7d01fff : iwlwifi
> f7e00000-f7e0ffff : 0000:00:14.0
> f7e00000-f7e0ffff : xhci_hcd
> f7e10000-f7e13fff : 0000:00:1b.0
> f7e10000-f7e13fff : ICH HD audio
> f7e15000-f7e150ff : 0000:00:1f.3
> f7e16000-f7e167ff : 0000:00:1f.2
> f7e16000-f7e167ff : ahci
> f7e17000-f7e173ff : 0000:00:1d.0
> f7e17000-f7e173ff : ehci_hcd
> f7e18000-f7e183ff : 0000:00:1a.0
> f7e18000-f7e183ff : ehci_hcd
> f7e1b000-f7e1b00f : 0000:00:16.0
> f7e1b000-f7e1b00f : mei_me
> f8000000-fbffffff : PCI MMCONFIG 0000 [bus 00-3f]
> f8000000-fbffffff : reserved
> f8000000-fbffffff : pnp 00:0a
> fe800000-fe802fff : pnp 00:07
> fec00000-fec00fff : reserved
> fec00000-fec003ff : IOAPIC 0
> fed00000-fed03fff : reserved
> fed00000-fed003ff : HPET 0
> fed10000-fed17fff : pnp 00:0a
> fed18000-fed18fff : pnp 00:0a
> fed19000-fed19fff : pnp 00:0a
> fed1c000-fed1ffff : reserved
> fed1c000-fed1ffff : pnp 00:0a
> fed1f410-fed1f414 : iTCO_wdt
> fed20000-fed3ffff : pnp 00:0a
> fed45000-fed8ffff : pnp 00:0a
> fed90000-fed93fff : pnp 00:0a
> fee00000-fee00fff : Local APIC
> fee00000-fee00fff : reserved
> ff000000-ffffffff : reserved
> ff000000-ffffffff : pnp 00:0a
> 100000000-11f5fffff : System RAM
> 11f600000-11fffffff : RAM buffer
>
> [8.5.] PCI information ('lspci -vvv' as root)
> 00:00.0 Host bridge: Intel Corporation 3rd Gen Core processor DRAM
> Controller (rev 09)
> Subsystem: Dell Device 057e
> Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx-
> Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort-
> <MAbort+ >SERR- <PERR- INTx-
> Latency: 0
> Capabilities: [e0] Vendor Specific Information: Len=0c <?>
>
> 00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor
> Graphics Controller (rev 09) (prog-if 00 [VGA controller])
> Subsystem: Dell Device 057e
> Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx+
> Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0
> Interrupt: pin A routed to IRQ 45
> Region 0: Memory at f7800000 (64-bit, non-prefetchable) [size=4M]
> Region 2: Memory at e0000000 (64-bit, prefetchable) [size=256M]
> Region 4: I/O ports at f000 [size=64]
> Expansion ROM at <unassigned> [disabled]
> Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
> Address: fee0f00c Data: 41e1
> Capabilities: [d0] Power Management version 2
> Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
> Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
> Capabilities: [a4] PCI Advanced Features
> AFCap: TP+ FLR+
> AFCtrl: FLR-
> AFStatus: TP-
> Kernel driver in use: i915
>
> 00:14.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset
> Family USB xHCI Host Controller (rev 04) (prog-if 30 [XHCI])
> Subsystem: Dell Device 057e
> Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx+
> Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0
> Interrupt: pin A routed to IRQ 40
> Region 0: Memory at f7e00000 (64-bit, non-prefetchable) [size=64K]
> Capabilities: [70] Power Management version 2
> Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0-,D1-,D2-,D3hot+,D3cold+)
> Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
> Capabilities: [80] MSI: Enable+ Count=1/8 Maskable- 64bit+
> Address: 00000000fee0f00c Data: 4181
> Kernel driver in use: xhci_hcd
>
> 00:16.0 Communication controller: Intel Corporation 7 Series/C210 Series
> Chipset Family MEI Controller #1 (rev 04)
> Subsystem: Dell Device 057e
> Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx+
> Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0
> Interrupt: pin A routed to IRQ 42
> Region 0: Memory at f7e1b000 (64-bit, non-prefetchable) [size=16]
> Capabilities: [50] Power Management version 3
> Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
> Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
> Capabilities: [8c] MSI: Enable+ Count=1/1 Maskable- 64bit+
> Address: 00000000fee0f00c Data: 41a1
> Kernel driver in use: mei_me
>
> 00:1a.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset
> Family USB Enhanced Host Controller #2 (rev 04) (prog-if 20 [EHCI])
> Subsystem: Dell Device 057e
> Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx-
> Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0
> Interrupt: pin A routed to IRQ 16
> Region 0: Memory at f7e18000 (32-bit, non-prefetchable) [size=1K]
> Capabilities: [50] Power Management version 2
> Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
> Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
> Capabilities: [58] Debug port: BAR=1 offset=00a0
> Capabilities: [98] PCI Advanced Features
> AFCap: TP+ FLR+
> AFCtrl: FLR-
> AFStatus: TP-
> Kernel driver in use: ehci-pci
>
> 00:1b.0 Audio device: Intel Corporation 7 Series/C210 Series Chipset Family
> High Definition Audio Controller (rev 04)
> Subsystem: Dell Device 057e
> Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx+
> Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0, Cache Line Size: 64 bytes
> Interrupt: pin A routed to IRQ 44
> Region 0: Memory at f7e10000 (64-bit, non-prefetchable) [size=16K]
> Capabilities: [50] Power Management version 2
> Flags: PMEClk- DSI- D1- D2- AuxCurrent=55mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
> Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
> Capabilities: [60] MSI: Enable+ Count=1/1 Maskable- 64bit+
> Address: 00000000fee0f00c Data: 41d1
> Capabilities: [70] Express (v1) Root Complex Integrated Endpoint, MSI 00
> DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us
> ExtTag- RBE- FLReset+
> DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
> RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
> MaxPayload 128 bytes, MaxReadReq 128 bytes
> DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend-
> LnkCap: Port #0, Speed unknown, Width x0, ASPM unknown, Latency L0 <64ns, L1
> <1us
> ClockPM- Surprise- LLActRep- BwNot-
> LnkCtl: ASPM Disabled; Disabled- Retrain- CommClk-
> ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
> LnkSta: Speed unknown, Width x0, TrErr- Train- SlotClk- DLActive- BWMgmt-
> ABWMgmt-
> Capabilities: [100 v1] Virtual Channel
> Caps: LPEVC=0 RefClk=100ns PATEntryBits=1
> Arb: Fixed- WRR32- WRR64- WRR128-
> Ctrl: ArbSelect=Fixed
> Status: InProgress-
> VC0: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
> Arb: Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256-
> Ctrl: Enable+ ID=0 ArbSelect=Fixed TC/VC=01
> Status: NegoPending- InProgress-
> VC1: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
> Arb: Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256-
> Ctrl: Enable+ ID=1 ArbSelect=Fixed TC/VC=22
> Status: NegoPending- InProgress-
> Capabilities: [130 v1] Root Complex Link
> Desc: PortNumber=0f ComponentID=00 EltType=Config
> Link0: Desc: TargetPort=00 TargetComponent=00 AssocRCRB- LinkType=MemMapped
> LinkValid+
> Addr: 00000000fed1c000
> Kernel driver in use: snd_hda_intel
>
> 00:1c.0 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family
> PCI Express Root Port 1 (rev c4) (prog-if 00 [Normal decode])
> Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx-
> Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0, Cache Line Size: 64 bytes
> Bus: primary=00, secondary=04, subordinate=04, sec-latency=0
> I/O behind bridge: 0000f000-00000fff
> Memory behind bridge: fff00000-000fffff
> Prefetchable memory behind bridge: 00000000fff00000-00000000000fffff
> Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort-
> <MAbort+ <SERR- <PERR-
> BridgeCtl: Parity- SERR- NoISA- VGA- MAbort- >Reset- FastB2B-
> PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn-
> Capabilities: [40] Express (v2) Root Port (Slot+), MSI 00
> DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us
> ExtTag- RBE+ FLReset-
> DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
> RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
> MaxPayload 128 bytes, MaxReadReq 128 bytes
> DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend-
> LnkCap: Port #1, Speed 5GT/s, Width x1, ASPM L0s L1, Latency L0 <1us, L1
> <16us
> ClockPM- Surprise- LLActRep+ BwNot-
> LnkCtl: ASPM L1 Enabled; RCB 64 bytes Disabled- Retrain- CommClk-
> ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
> LnkSta: Speed 2.5GT/s, Width x0, TrErr- Train- SlotClk+ DLActive- BWMgmt-
> ABWMgmt-
> SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug- Surprise-
> Slot #0, PowerLimit 10.000W; Interlock- NoCompl+
> SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet- CmdCplt- HPIrq- LinkChg-
> Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock-
> SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet- Interlock-
> Changed: MRL- PresDet- LinkState-
> RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna- CRSVisible-
> RootCap: CRSVisible-
> RootSta: PME ReqID 0000, PMEStatus- PMEPending-
> DevCap2: Completion Timeout: Range BC, TimeoutDis+ ARIFwd-
> DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis- ARIFwd-
> LnkCtl2: Target Link Speed: 5GT/s, EnterCompliance- SpeedDis-, Selectable
> De-emphasis: -6dB
> Transmit Margin: Normal Operating Range, EnterModifiedCompliance-
> ComplianceSOS-
> Compliance De-emphasis: -6dB
> LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete-,
> EqualizationPhase1-
> EqualizationPhase2-, EqualizationPhase3-, LinkEqualizationRequest-
> Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit-
> Address: 00000000 Data: 0000
> Capabilities: [90] Subsystem: Dell Device 057e
> Capabilities: [a0] Power Management version 2
> Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
> Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
> Kernel driver in use: pcieport
>
> 00:1c.3 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family
> PCI Express Root Port 4 (rev c4) (prog-if 00 [Normal decode])
> Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx-
> Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0, Cache Line Size: 64 bytes
> Bus: primary=00, secondary=07, subordinate=07, sec-latency=0
> I/O behind bridge: 0000f000-00000fff
> Memory behind bridge: f7d00000-f7dfffff
> Prefetchable memory behind bridge: 00000000fff00000-00000000000fffff
> Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort-
> <MAbort- <SERR- <PERR-
> BridgeCtl: Parity- SERR- NoISA- VGA- MAbort- >Reset- FastB2B-
> PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn-
> Capabilities: [40] Express (v2) Root Port (Slot+), MSI 00
> DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us
> ExtTag- RBE+ FLReset-
> DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
> RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
> MaxPayload 128 bytes, MaxReadReq 128 bytes
> DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend-
> LnkCap: Port #4, Speed 5GT/s, Width x1, ASPM L0s L1, Latency L0 <512ns, L1
> <16us
> ClockPM- Surprise- LLActRep+ BwNot-
> LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
> ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
> LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive+ BWMgmt+
> ABWMgmt-
> SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug- Surprise-
> Slot #3, PowerLimit 10.000W; Interlock- NoCompl+
> SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet- CmdCplt- HPIrq- LinkChg-
> Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock-
> SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet+ Interlock-
> Changed: MRL- PresDet- LinkState-
> RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna- CRSVisible-
> RootCap: CRSVisible-
> RootSta: PME ReqID 0000, PMEStatus- PMEPending-
> DevCap2: Completion Timeout: Range BC, TimeoutDis+ ARIFwd-
> DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis- ARIFwd-
> LnkCtl2: Target Link Speed: 5GT/s, EnterCompliance- SpeedDis-, Selectable
> De-emphasis: -6dB
> Transmit Margin: Normal Operating Range, EnterModifiedCompliance-
> ComplianceSOS-
> Compliance De-emphasis: -6dB
> LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete-,
> EqualizationPhase1-
> EqualizationPhase2-, EqualizationPhase3-, LinkEqualizationRequest-
> Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit-
> Address: 00000000 Data: 0000
> Capabilities: [90] Subsystem: Dell Device 057e
> Capabilities: [a0] Power Management version 2
> Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
> Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
> Kernel driver in use: pcieport
>
> 00:1c.5 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family
> PCI Express Root Port 6 (rev c4) (prog-if 00 [Normal decode])
> Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx-
> Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0, Cache Line Size: 64 bytes
> Bus: primary=00, secondary=09, subordinate=09, sec-latency=0
> I/O behind bridge: 0000e000-0000efff
> Memory behind bridge: f7c00000-f7cfffff
> Prefetchable memory behind bridge: 00000000fff00000-00000000000fffff
> Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort-
> <MAbort- <SERR- <PERR-
> BridgeCtl: Parity- SERR- NoISA- VGA- MAbort- >Reset- FastB2B-
> PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn-
> Capabilities: [40] Express (v2) Root Port (Slot+), MSI 00
> DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us
> ExtTag- RBE+ FLReset-
> DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
> RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
> MaxPayload 128 bytes, MaxReadReq 128 bytes
> DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend-
> LnkCap: Port #6, Speed 5GT/s, Width x1, ASPM L0s L1, Latency L0 <512ns, L1
> <16us
> ClockPM- Surprise- LLActRep+ BwNot-
> LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
> ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
> LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive+ BWMgmt+
> ABWMgmt-
> SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug- Surprise-
> Slot #5, PowerLimit 10.000W; Interlock- NoCompl+
> SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet- CmdCplt- HPIrq- LinkChg-
> Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock-
> SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet+ Interlock-
> Changed: MRL- PresDet- LinkState-
> RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna- CRSVisible-
> RootCap: CRSVisible-
> RootSta: PME ReqID 0000, PMEStatus- PMEPending-
> DevCap2: Completion Timeout: Range BC, TimeoutDis+ ARIFwd-
> DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis- ARIFwd-
> LnkCtl2: Target Link Speed: 5GT/s, EnterCompliance- SpeedDis-, Selectable
> De-emphasis: -6dB
> Transmit Margin: Normal Operating Range, EnterModifiedCompliance-
> ComplianceSOS-
> Compliance De-emphasis: -6dB
> LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete-,
> EqualizationPhase1-
> EqualizationPhase2-, EqualizationPhase3-, LinkEqualizationRequest-
> Capabilities: [80] MSI: Enable- Count=1/1 Maskable- 64bit-
> Address: 00000000 Data: 0000
> Capabilities: [90] Subsystem: Dell Device 057e
> Capabilities: [a0] Power Management version 2
> Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
> Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
> Kernel driver in use: pcieport
>
> 00:1d.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset
> Family USB Enhanced Host Controller #1 (rev 04) (prog-if 20 [EHCI])
> Subsystem: Dell Device 057e
> Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx-
> Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0
> Interrupt: pin A routed to IRQ 23
> Region 0: Memory at f7e17000 (32-bit, non-prefetchable) [size=1K]
> Capabilities: [50] Power Management version 2
> Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
> Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
> Capabilities: [58] Debug port: BAR=1 offset=00a0
> Capabilities: [98] PCI Advanced Features
> AFCap: TP+ FLR+
> AFCtrl: FLR-
> AFStatus: TP-
> Kernel driver in use: ehci-pci
>
> 00:1f.0 ISA bridge: Intel Corporation HM77 Express Chipset LPC Controller
> (rev 04)
> Subsystem: Dell Device 057e
> Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx-
> Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0
> Capabilities: [e0] Vendor Specific Information: Len=0c <?>
> Kernel driver in use: lpc_ich
>
> 00:1f.2 RAID bus controller: Intel Corporation 82801 Mobile SATA Controller
> [RAID mode] (rev 04)
> Subsystem: Dell Device 057e
> Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx+
> Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0
> Interrupt: pin B routed to IRQ 41
> Region 0: I/O ports at f0b0 [size=8]
> Region 1: I/O ports at f0a0 [size=4]
> Region 2: I/O ports at f090 [size=8]
> Region 3: I/O ports at f080 [size=4]
> Region 4: I/O ports at f060 [size=32]
> Region 5: Memory at f7e16000 (32-bit, non-prefetchable) [size=2K]
> Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
> Address: fee0500c Data: 4191
> Capabilities: [70] Power Management version 3
> Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot+,D3cold-)
> Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
> Capabilities: [a8] SATA HBA v1.0 BAR4 Offset=00000004
> Capabilities: [b0] PCI Advanced Features
> AFCap: TP+ FLR+
> AFCtrl: FLR-
> AFStatus: TP-
> Kernel driver in use: ahci
>
> 00:1f.3 SMBus: Intel Corporation 7 Series/C210 Series Chipset Family SMBus
> Controller (rev 04)
> Subsystem: Dell Device 057e
> Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx-
> Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Interrupt: pin C routed to IRQ 11
> Region 0: Memory at f7e15000 (64-bit, non-prefetchable) [size=256]
> Region 4: I/O ports at f040 [size=32]
>
> 07:00.0 Network controller: Intel Corporation Centrino Wireless-N 2230 (rev
> c4)
> Subsystem: Intel Corporation Centrino Wireless-N 2230 BGN
> Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx+
> Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0, Cache Line Size: 64 bytes
> Interrupt: pin A routed to IRQ 43
> Region 0: Memory at f7d00000 (64-bit, non-prefetchable) [size=8K]
> Capabilities: [c8] Power Management version 3
> Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
> Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
> Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
> Address: 00000000fee0400c Data: 41b1
> Capabilities: [e0] Express (v1) Endpoint, MSI 00
> DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <512ns, L1 unlimited
> ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset+
> DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
> RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop+ FLReset-
> MaxPayload 128 bytes, MaxReadReq 128 bytes
> DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend-
> LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 <4us, L1
> <32us
> ClockPM+ Surprise- LLActRep- BwNot-
> LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
> ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
> LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt-
> ABWMgmt-
> Capabilities: [100 v1] Advanced Error Reporting
> UESta: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP-
> ECRC- UnsupReq- ACSViol-
> UEMsk: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP-
> ECRC- UnsupReq- ACSViol-
> UESvrt: DLP+ SDES- TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+
> ECRC- UnsupReq- ACSViol-
> CESta: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr-
> CEMsk: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr+
> AERCap: First Error Pointer: 00, GenCap- CGenEn- ChkCap- ChkEn-
> Capabilities: [140 v1] Device Serial Number 60-36-dd-ff-ff-32-f8-6b
> Kernel driver in use: iwlwifi
>
> 09:00.0 Ethernet controller: Qualcomm Atheros AR8162 Fast Ethernet (rev 10)
> Subsystem: Dell Device 057e
> Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
> Stepping- SERR- FastB2B- DisINTx-
> Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort-
> <MAbort- >SERR- <PERR- INTx-
> Latency: 0, Cache Line Size: 64 bytes
> Interrupt: pin A routed to IRQ 46
> Region 0: Memory at f7c00000 (64-bit, non-prefetchable) [size=256K]
> Region 2: I/O ports at e000 [size=128]
> Capabilities: [40] Power Management version 3
> Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1+,D2+,D3hot+,D3cold+)
> Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
> Capabilities: [58] Express (v1) Endpoint, MSI 00
> DevCap: MaxPayload 4096 bytes, PhantFunc 0, Latency L0s unlimited, L1
> unlimited
> ExtTag- AttnBtn+ AttnInd+ PwrInd+ RBE+ FLReset-
> DevCtl: Report errors: Correctable+ Non-Fatal+ Fatal+ Unsupported+
> RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
> MaxPayload 128 bytes, MaxReadReq 512 bytes
> DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend-
> LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 unlimited,
> L1 unlimited
> ClockPM+ Surprise- LLActRep- BwNot-
> LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
> ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
> LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt-
> ABWMgmt-
> Capabilities: [c0] MSI: Enable+ Count=1/16 Maskable+ 64bit+
> Address: 00000000fee0f00c Data: 4122
> Masking: 0000fffe Pending: 00000000
> Capabilities: [d8] MSI-X: Enable- Count=16 Masked-
> Vector table: BAR=0 offset=00002000
> PBA: BAR=0 offset=00003000
> Capabilities: [100 v1] Advanced Error Reporting
> UESta: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP-
> ECRC- UnsupReq- ACSViol-
> UEMsk: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP-
> ECRC- UnsupReq- ACSViol-
> UESvrt: DLP- SDES+ TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+
> ECRC- UnsupReq- ACSViol-
> CESta: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr-
> CEMsk: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr+
> AERCap: First Error Pointer: 00, GenCap+ CGenEn- ChkCap+ ChkEn-
> Capabilities: [180 v1] Device Serial Number ff-ba-e6-31-78-45-c4-ff
> Kernel driver in use: alx
>
> [8.6.] SCSI information (from /proc/scsi/scsi)
> Attached devices:
> Host: scsi0 Channel: 00 Id: 00 Lun: 00
> Vendor: ATA Model: ST500LT012-9WS14 Rev: 0001
> Type: Direct-Access ANSI SCSI revision: 05
> Host: scsi1 Channel: 00 Id: 00 Lun: 00
> Vendor: ATA Model: Micron C400 Real Rev: 01MG
> Type: Direct-Access ANSI SCSI revision: 05
> Host: scsi4 Channel: 00 Id: 00 Lun: 00
> Vendor: HL-DT-ST Model: DVD+-RW GU70N Rev: A102
> Type: CD-ROM ANSI SCSI revision: 05
> Host: scsi6 Channel: 00 Id: 00 Lun: 00
> Vendor: Generic- Model: xD/SD/M.S. Rev: 1.00
> Type: Direct-Access ANSI SCSI revision: 02
>
> [8.7.] Other information that might be relevant to the problem
> (please look in /proc and include all information that you
> think to be relevant):
> N/A
>
> [X.] Other notes, patches, fixes, workarounds:
>
> The following one-line patch to 3.11-rc2 seems to make the problem go away:
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index bb456f4..b2e659c 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -1531,6 +1531,7 @@ static void update_cfs_rq_blocked_load(struct cfs_rq
> *cfs_rq, int force_update)
> }
>
> __update_cfs_rq_tg_load_contrib(cfs_rq, force_update);
> + update_cfs_shares(cfs_rq);
> }
>
> static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
>
>
>
>
>
>
Peter replied:
> Hi Max,
>
> Thanks for this elaborate bug report; I wish all of them were as
> thorough. However, is there a reason you omitted CC'ing LKML?
> > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> > index bb456f4..b2e659c 100644
> > --- a/kernel/sched/fair.c
> > +++ b/kernel/sched/fair.c
> > @@ -1531,6 +1531,7 @@ static void update_cfs_rq_blocked_load(struct cfs_rq *cfs_rq, int force_update)
> > }
> >
> > __update_cfs_rq_tg_load_contrib(cfs_rq, force_update);
> > + update_cfs_shares(cfs_rq);
> > }
> >
> > static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
>
> Ah I see what's happening. Currently we only call update_cfs_shares()
> from the enqueue/dequeue paths. However since your tasks never sleep and
> cannot migrate they never pass this code. This in turns means that the
> inter-cgroup relations (the shares) don't get updated.
>
> I think your patch would indeed be a correct minimal fix in that it adds
> a share update to the regular tick path ensuring it gets done even in
> the absence of enqueues/dequeues.
>> Ah I see what's happening. Currently we only call update_cfs_shares()
>> from the enqueue/dequeue paths. However since your tasks never sleep and
>> cannot migrate they never pass this code. This in turns means that the
>> inter-cgroup relations (the shares) don't get updated.
>>
>> I think your patch would indeed be a correct minimal fix in that it adds
>> a share update to the regular tick path ensuring it gets done even in
>> the absence of enqueues/dequeues.
Hmm.. /me scratches head.
We definitely _used_ to have a call to update_cfs_shares() in
update_cfs_rq_blocked_load() for _exactly_ this reason.
Let's see... a-ha.
It was originally part of:
f269ae0469fc882332bdfb5db15d3c1315fe2a10 sched: Update_cfs_shares at
period edge
But we reverted that right at the end of the merge window because the
amortization turned out to be too aggressive for interactive
workloads. This happened in 17bc14b767cf0692420c43dbe5310ae98a5a7836.
Unfortunately, when we did that, we lost the call to update_cfs_shares().
Yes, this wants to be there.
Reviewed-by: Paul Turner <[email protected]>
For a description how about something like:
sched: ensure update_cfs_shares() is called for parents of
continuously-running tasks
We typically update a task_group's shares within the dequeue/enqueue
path. However, continuously running tasks sharing a CPU are not
subject to these updates as they are only put/picked. Unfortunately,
when we reverted f269ae046 (in 17bc14b7), we lost the augmenting
periodic update that was supposed to account for this; resulting in a
potential loss of fairness.
To fix this, re-introduce the explicit update in
update_cfs_rq_blocked_load() [called via entity_tick()].
OK, so I have the below; however on a second look, Paul, shouldn't that
update_cfs_shares() call be in entity_tick(), right after calling
update_cfs_rq_blocked_load(). Because placing it in
update_cfs_rq_blocked_load() means its now called twice on the
enqueue/dequeue paths through:
{en,de}queue_entity()
{en,de}queue_entity_load_avg()
update_cfs_rq_blocked_load()
update_cfs_shares()
---
Subject: sched: Ensure update_cfs_shares() is called for parents of continuously-running tasks
From: Max Hailperin <[email protected]>
We typically update a task_group's shares within the dequeue/enqueue
path. However, continuously running tasks sharing a CPU are not
subject to these updates as they are only put/picked. Unfortunately,
when we reverted f269ae046 (in 17bc14b7), we lost the augmenting
periodic update that was supposed to account for this; resulting in a
potential loss of fairness.
To fix this, re-introduce the explicit update in
update_cfs_rq_blocked_load() [called via entity_tick()].
Cc: [email protected]
Reviewed-by: Paul Turner <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
---
kernel/sched/fair.c | 1 +
1 file changed, 1 insertion(+)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1531,6 +1531,7 @@ static void update_cfs_rq_blocked_load(s
}
__update_cfs_rq_tg_load_contrib(cfs_rq, force_update);
+ update_cfs_shares(cfs_rq);
}
static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
On Fri, Jul 26, 2013 at 2:03 PM, Peter Zijlstra <[email protected]> wrote:
>
>
> OK, so I have the below; however on a second look, Paul, shouldn't that
> update_cfs_shares() call be in entity_tick(), right after calling
> update_cfs_rq_blocked_load(). Because placing it in
> update_cfs_rq_blocked_load() means its now called twice on the
> enqueue/dequeue paths through:
>
> {en,de}queue_entity()
> {en,de}queue_entity_load_avg()
> update_cfs_rq_blocked_load()
> update_cfs_shares()
Yes, I agree: placing it directly in entity_tick() would be better.
[ In f269ae046 the calls to update_cfs_rq_blocked_load() were amortized
and the separate update in {en,de}queue_entity_load_avg() were
removed. ]
>
>
>
> ---
> Subject: sched: Ensure update_cfs_shares() is called for parents of continuously-running tasks
> From: Max Hailperin <[email protected]>
>
> We typically update a task_group's shares within the dequeue/enqueue
> path. However, continuously running tasks sharing a CPU are not
> subject to these updates as they are only put/picked. Unfortunately,
> when we reverted f269ae046 (in 17bc14b7), we lost the augmenting
> periodic update that was supposed to account for this; resulting in a
> potential loss of fairness.
>
> To fix this, re-introduce the explicit update in
> update_cfs_rq_blocked_load() [called via entity_tick()].
>
> Cc: [email protected]
> Reviewed-by: Paul Turner <[email protected]>
> Signed-off-by: Peter Zijlstra <[email protected]>
> ---
> kernel/sched/fair.c | 1 +
> 1 file changed, 1 insertion(+)
>
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -1531,6 +1531,7 @@ static void update_cfs_rq_blocked_load(s
> }
>
> __update_cfs_rq_tg_load_contrib(cfs_rq, force_update);
> + update_cfs_shares(cfs_rq);
> }
>
> static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
On Fri, Jul 26, 2013 at 02:24:50PM -0700, Paul Turner wrote:
> On Fri, Jul 26, 2013 at 2:03 PM, Peter Zijlstra <[email protected]> wrote:
> >
> >
> > OK, so I have the below; however on a second look, Paul, shouldn't that
> > update_cfs_shares() call be in entity_tick(), right after calling
> > update_cfs_rq_blocked_load(). Because placing it in
> > update_cfs_rq_blocked_load() means its now called twice on the
> > enqueue/dequeue paths through:
> >
> > {en,de}queue_entity()
> > {en,de}queue_entity_load_avg()
> > update_cfs_rq_blocked_load()
> > update_cfs_shares()
>
> Yes, I agree: placing it directly in entity_tick() would be better.
OK, how about the below then?
> [ In f269ae046 the calls to update_cfs_rq_blocked_load() were amortized
> and the separate update in {en,de}queue_entity_load_avg() were
> removed. ]
Right, I remember/saw that. Did you ever figure out why that regressed;
as in should we look to bring some of that back?
---
Subject: sched: Ensure update_cfs_shares() is called for parents of continuously-running tasks
From: Peter Zijlstra <[email protected]>
Date: Fri Jul 26 23:48:42 CEST 2013
We typically update a task_group's shares within the dequeue/enqueue
path. However, continuously running tasks sharing a CPU are not
subject to these updates as they are only put/picked. Unfortunately,
when we reverted f269ae046 (in 17bc14b7), we lost the augmenting
periodic update that was supposed to account for this; resulting in a
potential loss of fairness.
To fix this, re-introduce the explicit update in
update_cfs_rq_blocked_load() [called via entity_tick()].
Cc: [email protected]
Reported-by: Max Hailperin <[email protected]>
Reviewed-by: Paul Turner <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
---
kernel/sched/fair.c | 1 +
1 file changed, 1 insertion(+)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2032,6 +2032,7 @@ entity_tick(struct cfs_rq *cfs_rq, struc
*/
update_entity_load_avg(curr, 1);
update_cfs_rq_blocked_load(cfs_rq, 1);
+ update_cfs_shares(cfs_rq);
#ifdef CONFIG_SCHED_HRTICK
/*
On Fri, Jul 26, 2013 at 2:50 PM, Peter Zijlstra <[email protected]> wrote:
> On Fri, Jul 26, 2013 at 02:24:50PM -0700, Paul Turner wrote:
>> On Fri, Jul 26, 2013 at 2:03 PM, Peter Zijlstra <[email protected]> wrote:
>> >
>> >
>> > OK, so I have the below; however on a second look, Paul, shouldn't that
>> > update_cfs_shares() call be in entity_tick(), right after calling
>> > update_cfs_rq_blocked_load(). Because placing it in
>> > update_cfs_rq_blocked_load() means its now called twice on the
>> > enqueue/dequeue paths through:
>> >
>> > {en,de}queue_entity()
>> > {en,de}queue_entity_load_avg()
>> > update_cfs_rq_blocked_load()
>> > update_cfs_shares()
>>
>> Yes, I agree: placing it directly in entity_tick() would be better.
>
> OK, how about the below then?
Looks good.
>
>> [ In f269ae046 the calls to update_cfs_rq_blocked_load() were amortized
>> and the separate update in {en,de}queue_entity_load_avg() were
>> removed. ]
>
> Right, I remember/saw that. Did you ever figure out why that regressed;
> as in should we look to bring some of that back?
Yes, the savings are measurable (we actually still use it internally).
So the particular problem in Linus's workload was that the amortization meant
that there was more delay until the first update for a newly created task. This
then had negative interactivity with a make -j <N> workload since it allowed the
tasks to be over-represented in terms of the group shares they received.
With:
a75cdaa9: "sched: Set an initial value of runnable avg for new forked task"
This should now be improved so we should look at bringing it back.