Hi Jacob, Zhang,
One of your recent commit "thermal/powerclamp: remove cpu whitelist” [1], has caused a regression in the kernel.
That commit changed powerclamp_probe from requiring all of the following features:
X86_FEATURE_NONSTOP_TSC
X86_FEATURE_CONSTANT_TSC
X86_FEATURE_MWAIT
X86_FEATURE_ARAT
to *any* of them. The problem is clamp_thread still wants to use mwait_idle_with_hints even if the CPU doesn't support it.
This was reported by our users when running ubuntu 16.10 (4.8.0-22-generic) inside a VMware VM, though as mentioned above I don’t think it is specific to our platform. We have seen kernel panics due to invalid opcode because of this. Below is the stack trace for your reference.
[ 5.736416] invalid opcode: 0000 [#1] SMP
[ 5.736455] Modules linked in: vmw_vsock_vmci_transport vsock vmw_balloon intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw glue_helper ablk_helper cryptd intel_rapl_perf input_leds joydev serio_raw snd_ens1371 snd_ac97_codec gameport ac97_bus snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer snd soundcore i2c_piix4 shpchp vmw_vmci nfit floppy(+) mac_hid parport_pc ppdev lp parport ip_tables x_tables autofs4 hid_generic usbhid hid ahci libahci e1000 mptspi mptscsih psmouse mptbase vmwgfx scsi_transport_spi ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm pata_acpi fjes
[ 5.744370] CPU: 1 PID: 912 Comm: kidle_inject/1 Not tainted 4.8.0-22-generic #24-Ubuntu
[ 5.744373] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015
[ 5.744375] task: ffff9658f7a663c0 task.stack: ffff9658fa908000
[ 5.744378] RIP: 0010:[<ffffffffc05728b8>] [<ffffffffc05728b8>] clamp_thread+0x2b8/0x5d0 [intel_powerclamp]
[ 5.744380] RSP: 0018:ffff9658fa90be00 EFLAGS: 00010246
[ 5.744383] RAX: ffff9658fa908008 RBX: 00000000fffee0a6 RCX: 0000000000000000
[ 5.744386] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246
[ 5.744388] RBP: ffff9658fa90bec0 R08: ffff9658fa908000 R09: 0000000000000000
[ 5.744391] R10: 000000000001cbf7 R11: 0000000000000000 R12: ffffffff8db581a0
[ 5.744393] R13: ffff9658fa908000 R14: 0000000000000000 R15: ffff9658fa908000
[ 5.744396] FS: 0000000000000000(0000) GS:ffff9658fc640000(0000) knlGS:0000000000000000
[ 5.744398] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5.744401] CR2: 00007ffa6cc262e8 CR3: 000000003ab3b000 CR4: 00000000001406e0
[ 5.744403] Stack:
[ 5.744406] 0000000000000001 ffff9658f7a66dc0 ffff9658fc659200 00000000e878d638
[ 5.744409] 0000000000000001 00000002fc659200 0000000000000001 ffff9658fa908008
[ 5.744411] 0000000000000000 ffff9658fc64fea8 00000000fffee0a6 ffffffffc05720a0
[ 5.744414] Call Trace:
[ 5.744416] [<ffffffffc05720a0>] ? pkg_state_counter+0xa0/0xa0 [intel_powerclamp]
[ 5.744419] [<ffffffffc0572600>] ? powerclamp_set_cur_state+0x170/0x170 [intel_powerclamp]
[ 5.744421] [<ffffffffc0572600>] ? powerclamp_set_cur_state+0x170/0x170 [intel_powerclamp]
[ 5.744424] [<ffffffff8cca3c18>] kthread+0xd8/0xf0
[ 5.744427] [<ffffffff8d49f29f>] ret_from_fork+0x1f/0x40
[ 5.744429] [<ffffffff8cca3b40>] ? kthread_create_on_node+0x1e0/0x1e0
[ 5.744432] Code: cc e9 ba 00 00 00 eb 19 0f 1f 00 0f ae f0 65 48 8b 04 25 04 69 01 00 0f ae b8 08 c0 ff ff 0f ae f0 31 d2 48 8b 44 24 38 48 89 d1 <0f> 01 c8 49 8b 45 08 a8 08 75 0b b9 01 00 00 00 4c 89 f0 0f 01
[ 5.744434] RIP [<ffffffffc05728b8>] clamp_thread+0x2b8/0x5d0 [intel_powerclamp]
[ 5.744437] RSP <ffff9658fa90be00>
[ 5.744440] invalid opcode: 0000 [#2] SMP
[ 5.744452] ---[ end trace cf659c4076bf2804 ]---
Looking at the instruction at the RIP <ffffffffc05728b8> shows that the kernel attempted to execute “monitor” instruction.
8b8: 0f 01 c8 monitor %rax,%rcx,%rdx
8bb: 49 8b 45 08 mov 0x8(%r13),%rax
To fix this, I think you should restore the explicit feature check “if block” that was removed in the above mentioned commit. Can you please look at this ?
Thanks,
Alok
[1] b721ca0d192754deccb89fb01c77e41e6fd91ad9
https://github.com/torvalds/linux/commit/b721ca0d192754deccb89fb01c77e41e6fd91ad9,
On Tue, 18 Oct 2016 14:20:49 +0000
Alok Kataria <[email protected]> wrote:
> Hi Jacob, Zhang,
>
> One of your recent commit "thermal/powerclamp: remove cpu
> whitelist” [1], has caused a regression in the kernel.
>
> That commit changed powerclamp_probe from requiring all of the
> following features:
>
> X86_FEATURE_NONSTOP_TSC
> X86_FEATURE_CONSTANT_TSC
> X86_FEATURE_MWAIT
> X86_FEATURE_ARAT
>
> to *any* of them. The problem is clamp_thread still wants to use
> mwait_idle_with_hints even if the CPU doesn't support it.
>
Hi Alok,
You are right, it should be AND not OR.
+Eric who has a patch to address this.
https://patchwork.kernel.org/patch/9365005/
Rui/Rafael,
Could you consider this as an urgent fix?
Jacob
> This was reported by our users when running ubuntu 16.10
> (4.8.0-22-generic) inside a VMware VM, though as mentioned above I
> don’t think it is specific to our platform. We have seen kernel
> panics due to invalid opcode because of this. Below is the stack
> trace for your reference.
>
> [ 5.736416] invalid opcode: 0000 [#1] SMP
> [ 5.736455] Modules linked in: vmw_vsock_vmci_transport vsock
> vmw_balloon intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul
> ghash_clmulni_intel aesni_intel aes_x86_64 lrw glue_helper
> ablk_helper cryptd intel_rapl_perf input_leds joydev serio_raw
> snd_ens1371 snd_ac97_codec gameport ac97_bus snd_pcm snd_seq_midi
> snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer snd
> soundcore i2c_piix4 shpchp vmw_vmci nfit floppy(+) mac_hid parport_pc
> ppdev lp parport ip_tables x_tables autofs4 hid_generic usbhid hid
> ahci libahci e1000 mptspi mptscsih psmouse mptbase vmwgfx
> scsi_transport_spi ttm drm_kms_helper syscopyarea sysfillrect
> sysimgblt fb_sys_fops drm pata_acpi fjes [ 5.744370] CPU: 1 PID:
> 912 Comm: kidle_inject/1 Not tainted 4.8.0-22-generic #24-Ubuntu
> [ 5.744373] Hardware name: VMware, Inc. VMware Virtual
> Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015
> [ 5.744375] task: ffff9658f7a663c0 task.stack: ffff9658fa908000
> [ 5.744378] RIP: 0010:[<ffffffffc05728b8>] [<ffffffffc05728b8>]
> clamp_thread+0x2b8/0x5d0 [intel_powerclamp] [ 5.744380] RSP:
> 0018:ffff9658fa90be00 EFLAGS: 00010246 [ 5.744383] RAX:
> ffff9658fa908008 RBX: 00000000fffee0a6 RCX: 0000000000000000
> [ 5.744386] RDX: 0000000000000000 RSI: 0000000000000246 RDI:
> 0000000000000246 [ 5.744388] RBP: ffff9658fa90bec0 R08:
> ffff9658fa908000 R09: 0000000000000000 [ 5.744391] R10:
> 000000000001cbf7 R11: 0000000000000000 R12: ffffffff8db581a0
> [ 5.744393] R13: ffff9658fa908000 R14: 0000000000000000 R15:
> ffff9658fa908000 [ 5.744396] FS: 0000000000000000(0000)
> GS:ffff9658fc640000(0000) knlGS:0000000000000000 [ 5.744398] CS:
> 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5.744401] CR2:
> 00007ffa6cc262e8 CR3: 000000003ab3b000 CR4: 00000000001406e0
> [ 5.744403] Stack: [ 5.744406] 0000000000000001
> ffff9658f7a66dc0 ffff9658fc659200 00000000e878d638 [ 5.744409]
> 0000000000000001 00000002fc659200 0000000000000001 ffff9658fa908008
> [ 5.744411] 0000000000000000 ffff9658fc64fea8 00000000fffee0a6
> ffffffffc05720a0 [ 5.744414] Call Trace: [ 5.744416]
> [<ffffffffc05720a0>] ? pkg_state_counter+0xa0/0xa0 [intel_powerclamp]
> [ 5.744419] [<ffffffffc0572600>] ?
> powerclamp_set_cur_state+0x170/0x170 [intel_powerclamp]
> [ 5.744421] [<ffffffffc0572600>] ?
> powerclamp_set_cur_state+0x170/0x170 [intel_powerclamp]
> [ 5.744424] [<ffffffff8cca3c18>] kthread+0xd8/0xf0
> [ 5.744427] [<ffffffff8d49f29f>] ret_from_fork+0x1f/0x40
> [ 5.744429] [<ffffffff8cca3b40>] ?
> kthread_create_on_node+0x1e0/0x1e0 [ 5.744432] Code: cc e9 ba 00
> 00 00 eb 19 0f 1f 00 0f ae f0 65 48 8b 04 25 04 69 01 00 0f ae b8 08
> c0 ff ff 0f ae f0 31 d2 48 8b 44 24 38 48 89 d1 <0f> 01 c8 49 8b 45
> 08 a8 08 75 0b b9 01 00 00 00 4c 89 f0 0f 01 [ 5.744434] RIP
> [<ffffffffc05728b8>] clamp_thread+0x2b8/0x5d0 [intel_powerclamp]
> [ 5.744437] RSP <ffff9658fa90be00> [ 5.744440] invalid opcode:
> 0000 [#2] SMP [ 5.744452] ---[ end trace cf659c4076bf2804 ]---
>
> Looking at the instruction at the RIP <ffffffffc05728b8> shows that
> the kernel attempted to execute “monitor” instruction.
>
> 8b8: 0f 01 c8 monitor %rax,%rcx,%rdx
> 8bb: 49 8b 45 08 mov 0x8(%r13),%rax
>
> To fix this, I think you should restore the explicit feature check
> “if block” that was removed in the above mentioned commit. Can you
> please look at this ?
>
> Thanks,
> Alok
>
>
> [1] b721ca0d192754deccb89fb01c77e41e6fd91ad9
> https://github.com/torvalds/linux/commit/b721ca0d192754deccb89fb01c77e41e6fd91ad9,
>
[Jacob Pan]
On Wed, 2016-10-19 at 20:45 -0700, Jacob Pan wrote:
> On Tue, 18 Oct 2016 14:20:49 +0000
> Alok Kataria <[email protected]> wrote:
>
> > Hi Jacob, Zhang,
> >
> > One of your recent commit "thermal/powerclamp: remove cpu
> > whitelist” [1], has caused a regression in the kernel.
> >
> > That commit changed powerclamp_probe from requiring all of the
> > following features:
> >
> > X86_FEATURE_NONSTOP_TSC
> > X86_FEATURE_CONSTANT_TSC
> > X86_FEATURE_MWAIT
> > X86_FEATURE_ARAT
> >
> > to *any* of them. The problem is clamp_thread still wants to use
> > mwait_idle_with_hints even if the CPU doesn't support it.
> >
> Hi Alok,
>
> You are right, it should be AND not OR.
>
> +Eric who has a patch to address this.
>
> https://patchwork.kernel.org/patch/9365005/
Thanks Jacob.
Also, I don't see stable copied on that submission, shouldn't this be a
candidate for backporting to all affected kernel versions ?
Thanks,
Alok
>
> Rui/Rafael,
>
> Could you consider this as an urgent fix?
>
> Jacob
> > This was reported by our users when running ubuntu 16.10
> > (4.8.0-22-generic) inside a VMware VM, though as mentioned above I
> > don’t think it is specific to our platform. We have seen kernel
> > panics due to invalid opcode because of this. Below is the stack
> > trace for your reference.
> >
> > [ 5.736416] invalid opcode: 0000 [#1] SMP
> > [ 5.736455] Modules linked in: vmw_vsock_vmci_transport vsock
> > vmw_balloon intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul
> > ghash_clmulni_intel aesni_intel aes_x86_64 lrw glue_helper
> > ablk_helper cryptd intel_rapl_perf input_leds joydev serio_raw
> > snd_ens1371 snd_ac97_codec gameport ac97_bus snd_pcm snd_seq_midi
> > snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer snd
> > soundcore i2c_piix4 shpchp vmw_vmci nfit floppy(+) mac_hid parport_pc
> > ppdev lp parport ip_tables x_tables autofs4 hid_generic usbhid hid
> > ahci libahci e1000 mptspi mptscsih psmouse mptbase vmwgfx
> > scsi_transport_spi ttm drm_kms_helper syscopyarea sysfillrect
> > sysimgblt fb_sys_fops drm pata_acpi fjes [ 5.744370] CPU: 1 PID:
> > 912 Comm: kidle_inject/1 Not tainted 4.8.0-22-generic #24-Ubuntu
> > [ 5.744373] Hardware name: VMware, Inc. VMware Virtual
> > Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015
> > [ 5.744375] task: ffff9658f7a663c0 task.stack: ffff9658fa908000
> > [ 5.744378] RIP: 0010:[<ffffffffc05728b8>] [<ffffffffc05728b8>]
> > clamp_thread+0x2b8/0x5d0 [intel_powerclamp] [ 5.744380] RSP:
> > 0018:ffff9658fa90be00 EFLAGS: 00010246 [ 5.744383] RAX:
> > ffff9658fa908008 RBX: 00000000fffee0a6 RCX: 0000000000000000
> > [ 5.744386] RDX: 0000000000000000 RSI: 0000000000000246 RDI:
> > 0000000000000246 [ 5.744388] RBP: ffff9658fa90bec0 R08:
> > ffff9658fa908000 R09: 0000000000000000 [ 5.744391] R10:
> > 000000000001cbf7 R11: 0000000000000000 R12: ffffffff8db581a0
> > [ 5.744393] R13: ffff9658fa908000 R14: 0000000000000000 R15:
> > ffff9658fa908000 [ 5.744396] FS: 0000000000000000(0000)
> > GS:ffff9658fc640000(0000) knlGS:0000000000000000 [ 5.744398] CS:
> > 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5.744401] CR2:
> > 00007ffa6cc262e8 CR3: 000000003ab3b000 CR4: 00000000001406e0
> > [ 5.744403] Stack: [ 5.744406] 0000000000000001
> > ffff9658f7a66dc0 ffff9658fc659200 00000000e878d638 [ 5.744409]
> > 0000000000000001 00000002fc659200 0000000000000001 ffff9658fa908008
> > [ 5.744411] 0000000000000000 ffff9658fc64fea8 00000000fffee0a6
> > ffffffffc05720a0 [ 5.744414] Call Trace: [ 5.744416]
> > [<ffffffffc05720a0>] ? pkg_state_counter+0xa0/0xa0 [intel_powerclamp]
> > [ 5.744419] [<ffffffffc0572600>] ?
> > powerclamp_set_cur_state+0x170/0x170 [intel_powerclamp]
> > [ 5.744421] [<ffffffffc0572600>] ?
> > powerclamp_set_cur_state+0x170/0x170 [intel_powerclamp]
> > [ 5.744424] [<ffffffff8cca3c18>] kthread+0xd8/0xf0
> > [ 5.744427] [<ffffffff8d49f29f>] ret_from_fork+0x1f/0x40
> > [ 5.744429] [<ffffffff8cca3b40>] ?
> > kthread_create_on_node+0x1e0/0x1e0 [ 5.744432] Code: cc e9 ba 00
> > 00 00 eb 19 0f 1f 00 0f ae f0 65 48 8b 04 25 04 69 01 00 0f ae b8 08
> > c0 ff ff 0f ae f0 31 d2 48 8b 44 24 38 48 89 d1 <0f> 01 c8 49 8b 45
> > 08 a8 08 75 0b b9 01 00 00 00 4c 89 f0 0f 01 [ 5.744434] RIP
> > [<ffffffffc05728b8>] clamp_thread+0x2b8/0x5d0 [intel_powerclamp]
> > [ 5.744437] RSP <ffff9658fa90be00> [ 5.744440] invalid opcode:
> > 0000 [#2] SMP [ 5.744452] ---[ end trace cf659c4076bf2804 ]---
> >
> > Looking at the instruction at the RIP <ffffffffc05728b8> shows that
> > the kernel attempted to execute “monitor” instruction.
> >
> > 8b8: 0f 01 c8 monitor %rax,%rcx,%rdx
> > 8bb: 49 8b 45 08 mov 0x8(%r13),%rax
> >
> > To fix this, I think you should restore the explicit feature check
> > “if block” that was removed in the above mentioned commit. Can you
> > please look at this ?
> >
> > Thanks,
> > Alok
> >
> >
> > [1] b721ca0d192754deccb89fb01c77e41e6fd91ad9
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_torvalds_linux_commit_b721ca0d192754deccb89fb01c77e41e6fd91ad9&d=CwIFaQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=2AkLWShm6V8Nuu8ZZ-80Flo6y0XxCGmO1xrsAeRArAE&m=7uVsMg9U267LoIREKGqRgG6PRN0CXj7r4Or_eZkIGSc&s=k4SUhjPw1E7qeXBt7d40wlxcG1Bh4bXI-nosLw5SdYM&e= ,
> >
>
> [Jacob Pan]
On Wed, 2016-10-19 at 20:45 -0700, Jacob Pan wrote:
> On Tue, 18 Oct 2016 14:20:49 +0000
> Alok Kataria <[email protected]> wrote:
>
> >
> > Hi Jacob, Zhang,
> >
> > One of your recent commit "thermal/powerclamp: remove cpu
> > whitelist” [1], has caused a regression in the kernel.
> >
> > That commit changed powerclamp_probe from requiring all of the
> > following features:
> >
> > X86_FEATURE_NONSTOP_TSC
> > X86_FEATURE_CONSTANT_TSC
> > X86_FEATURE_MWAIT
> > X86_FEATURE_ARAT
> >
> > to *any* of them. The problem is clamp_thread still wants to use
> > mwait_idle_with_hints even if the CPU doesn't support it.
> >
> Hi Alok,
>
> You are right, it should be AND not OR.
>
> +Eric who has a patch to address this.
>
> https://patchwork.kernel.org/patch/9365005/
>
> Rui/Rafael,
>
> Could you consider this as an urgent fix?
>
yeah, will include this for next -rc. And cc stable v4.7+.
thanks,
rui
> Jacob
> >
> > This was reported by our users when running ubuntu 16.10
> > (4.8.0-22-generic) inside a VMware VM, though as mentioned above I
> > don’t think it is specific to our platform. We have seen kernel
> > panics due to invalid opcode because of this. Below is the stack
> > trace for your reference.
> >
> > [ 5.736416] invalid opcode: 0000 [#1] SMP
> > [ 5.736455] Modules linked in: vmw_vsock_vmci_transport vsock
> > vmw_balloon intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul
> > ghash_clmulni_intel aesni_intel aes_x86_64 lrw glue_helper
> > ablk_helper cryptd intel_rapl_perf input_leds joydev serio_raw
> > snd_ens1371 snd_ac97_codec gameport ac97_bus snd_pcm snd_seq_midi
> > snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer snd
> > soundcore i2c_piix4 shpchp vmw_vmci nfit floppy(+) mac_hid
> > parport_pc
> > ppdev lp parport ip_tables x_tables autofs4 hid_generic usbhid hid
> > ahci libahci e1000 mptspi mptscsih psmouse mptbase vmwgfx
> > scsi_transport_spi ttm drm_kms_helper syscopyarea sysfillrect
> > sysimgblt fb_sys_fops drm pata_acpi fjes [ 5.744370] CPU: 1 PID:
> > 912 Comm: kidle_inject/1 Not tainted 4.8.0-22-generic #24-Ubuntu
> > [ 5.744373] Hardware name: VMware, Inc. VMware Virtual
> > Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015
> > [ 5.744375] task: ffff9658f7a663c0 task.stack: ffff9658fa908000
> > [ 5.744378] RIP: 0010:[<ffffffffc05728b8>] [<ffffffffc05728b8>]
> > clamp_thread+0x2b8/0x5d0 [intel_powerclamp] [ 5.744380] RSP:
> > 0018:ffff9658fa90be00 EFLAGS: 00010246 [ 5.744383] RAX:
> > ffff9658fa908008 RBX: 00000000fffee0a6 RCX: 0000000000000000
> > [ 5.744386] RDX: 0000000000000000 RSI: 0000000000000246 RDI:
> > 0000000000000246 [ 5.744388] RBP: ffff9658fa90bec0 R08:
> > ffff9658fa908000 R09: 0000000000000000 [ 5.744391] R10:
> > 000000000001cbf7 R11: 0000000000000000 R12: ffffffff8db581a0
> > [ 5.744393] R13: ffff9658fa908000 R14: 0000000000000000 R15:
> > ffff9658fa908000 [ 5.744396] FS: 0000000000000000(0000)
> > GS:ffff9658fc640000(0000) knlGS:0000000000000000 [ 5.744398] CS:
> > 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5.744401] CR2:
> > 00007ffa6cc262e8 CR3: 000000003ab3b000 CR4: 00000000001406e0
> > [ 5.744403] Stack: [ 5.744406] 0000000000000001
> > ffff9658f7a66dc0 ffff9658fc659200 00000000e878d638 [ 5.744409]
> > 0000000000000001 00000002fc659200 0000000000000001 ffff9658fa908008
> > [ 5.744411] 0000000000000000 ffff9658fc64fea8 00000000fffee0a6
> > ffffffffc05720a0 [ 5.744414] Call Trace: [ 5.744416]
> > [<ffffffffc05720a0>] ? pkg_state_counter+0xa0/0xa0
> > [intel_powerclamp]
> > [ 5.744419] [<ffffffffc0572600>] ?
> > powerclamp_set_cur_state+0x170/0x170 [intel_powerclamp]
> > [ 5.744421] [<ffffffffc0572600>] ?
> > powerclamp_set_cur_state+0x170/0x170 [intel_powerclamp]
> > [ 5.744424] [<ffffffff8cca3c18>] kthread+0xd8/0xf0
> > [ 5.744427] [<ffffffff8d49f29f>] ret_from_fork+0x1f/0x40
> > [ 5.744429] [<ffffffff8cca3b40>] ?
> > kthread_create_on_node+0x1e0/0x1e0 [ 5.744432] Code: cc e9 ba 00
> > 00 00 eb 19 0f 1f 00 0f ae f0 65 48 8b 04 25 04 69 01 00 0f ae b8
> > 08
> > c0 ff ff 0f ae f0 31 d2 48 8b 44 24 38 48 89 d1 <0f> 01 c8 49 8b 45
> > 08 a8 08 75 0b b9 01 00 00 00 4c 89 f0 0f 01 [ 5.744434] RIP
> > [<ffffffffc05728b8>] clamp_thread+0x2b8/0x5d0 [intel_powerclamp]
> > [ 5.744437] RSP <ffff9658fa90be00> [ 5.744440] invalid
> > opcode:
> > 0000 [#2] SMP [ 5.744452] ---[ end trace cf659c4076bf2804 ]---
> >
> > Looking at the instruction at the RIP <ffffffffc05728b8> shows that
> > the kernel attempted to execute “monitor” instruction.
> >
> > 8b8: 0f 01 c8 monitor %rax,%rcx,%rdx
> > 8bb: 49 8b 45 08 mov 0x8(%r13),%rax
> >
> > To fix this, I think you should restore the explicit feature check
> > “if block” that was removed in the above mentioned commit. Can you
> > please look at this ?
> >
> > Thanks,
> > Alok
> >
> >
> > [1] b721ca0d192754deccb89fb01c77e41e6fd91ad9
> > https://github.com/torvalds/linux/commit/b721ca0d192754deccb89fb01c
> > 77e41e6fd91ad9,
> >
> [Jacob Pan]