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cpufreq: prevent 'policy->cpus' become offline in __gov_queue_work()

PATCH In review Michael Wang 3 participants 4 messages Jun 5, 2013 CPU frequency scaling framework

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Michael Wang

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#0 lore raw

PATCH 1/1 cpufreq: prevent 'policy->cpus' become offline in __gov_queue_work()

Jiri Kosina <[email protected]> and Borislav Petkov <[email protected]> reported the warning:

[   51.616759] ------------[ cut here ]------------
[   51.621460] WARNING: at arch/x86/kernel/smp.c:123 native_smp_send_reschedule+0x58/0x60()
[   51.629638] Modules linked in: ext2 vfat fat loop snd_hda_codec_hdmi usbhid snd_hda_codec_realtek coretemp kvm_intel kvm snd_hda_intel snd_hda_codec crc32_pclmul crc32c_intel ghash_clmulni_intel snd_hwdep snd_pcm aesni_intel sb_edac aes_x86_64 ehci_pci snd_page_alloc glue_helper snd_timer xhci_hcd snd iTCO_wdt iTCO_vendor_support ehci_hcd edac_core lpc_ich acpi_cpufreq lrw gf128mul ablk_helper cryptd mperf usbcore usb_common soundcore mfd_core dcdbas evdev pcspkr processor i2c_i801 button microcode
[   51.675581] CPU: 0 PID: 244 Comm: kworker/1:1 Tainted: G        W    3.10.0-rc1+ #10
[   51.683407] Hardware name: Dell Inc. Precision T3600/0PTTT9, BIOS A08 01/24/2013
[   51.690901] Workqueue: events od_dbs_timer
[   51.695069]  0000000000000009 ffff88043a2f5b68 ffffffff8161441c ffff88043a2f5ba8
[   51.702602]  ffffffff8103e540 0000000000000033 0000000000000001 ffff88043d5f8000
[   51.710136]  00000000ffff0ce1 0000000000000001 ffff88044fc4fc08 ffff88043a2f5bb8
[   51.717691] Call Trace:
[   51.720191]  [<ffffffff8161441c>] dump_stack+0x19/0x1b
[   51.725396]  [<ffffffff8103e540>] warn_slowpath_common+0x70/0xa0
[   51.731473]  [<ffffffff8103e58a>] warn_slowpath_null+0x1a/0x20
[   51.737378]  [<ffffffff81025628>] native_smp_send_reschedule+0x58/0x60
[   51.744013]  [<ffffffff81072cfd>] wake_up_nohz_cpu+0x2d/0xa0
[   51.749745]  [<ffffffff8104f6bf>] add_timer_on+0x8f/0x110
[   51.755214]  [<ffffffff8105f6fe>] __queue_delayed_work+0x16e/0x1a0
[   51.761470]  [<ffffffff8105f251>] ? try_to_grab_pending+0xd1/0x1a0
[   51.767724]  [<ffffffff8105f78a>] mod_delayed_work_on+0x5a/0xa0
[   51.773719]  [<ffffffff814f6b5d>] gov_queue_work+0x4d/0xc0
[   51.779271]  [<ffffffff814f60cb>] od_dbs_timer+0xcb/0x170
[   51.784734]  [<ffffffff8105e75d>] process_one_work+0x1fd/0x540
[   51.790634]  [<ffffffff8105e6f2>] ? process_one_work+0x192/0x540
[   51.796711]  [<ffffffff8105ef22>] worker_thread+0x122/0x380
[   51.802350]  [<ffffffff8105ee00>] ? rescuer_thread+0x320/0x320
[   51.808264]  [<ffffffff8106634a>] kthread+0xea/0xf0
[   51.813200]  [<ffffffff81066260>] ? flush_kthread_worker+0x150/0x150
[   51.819644]  [<ffffffff81623d5c>] ret_from_fork+0x7c/0xb0
[   51.918165] nouveau E[     DRM] GPU lockup - switching to software fbcon
[   51.930505]  [<ffffffff81066260>] ? flush_kthread_worker+0x150/0x150
[   51.936994] ---[ end trace f419538ada83b5c5 ]---

It was caused by the policy->cpus changed during the process of __gov_queue_work(), in other word, cpu offline happened.

This patch will use get/put_online_cpus() to prevent the offline happen inside __gov_queue_work(), after applied the patch, the warning is gone as Jiri tested:

	Link: https://lkml.org/lkml/2013/6/5/88
CC "Rafael J. Wysocki" <[email protected]>
CC Viresh Kumar <[email protected]>
Reported-by Borislav Petkov <[email protected]>
Reported-by Jiri Kosina <[email protected]>
Tested-by Jiri Kosina <[email protected]>
Signed-off-by Michael Wang <[email protected]>
---
 drivers/cpufreq/cpufreq_governor.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
drivers/cpufreq/cpufreq_governor.c +3 -0
index 5af40ad..dc9b72e 100644
@@ -26,6 +26,7 @@
 #include <linux/tick.h>
 #include <linux/types.h>
 #include <linux/workqueue.h>
+#include <linux/cpu.h>
 
 #include "cpufreq_governor.h"
 

@@ -180,8 +181,10 @@ void gov_queue_work(struct dbs_data *dbs_data, struct cpufreq_policy *policy,
 	if (!all_cpus) {
 		__gov_queue_work(smp_processor_id(), dbs_data, delay);
 	} else {
+		get_online_cpus();
 		for_each_cpu(i, policy->cpus)
 			__gov_queue_work(i, dbs_data, delay);
+		put_online_cpus();
 	}
 }
 EXPORT_SYMBOL_GPL(gov_queue_work);
Signature · 1 line
1.7.4.1
maintainer Acked-by on v1 1/1
#1 lore raw
Quoted 51 lines · Michael Wang

Jiri Kosina <[email protected]> and Borislav Petkov <[email protected]> reported the warning:

[   51.616759] ------------[ cut here ]------------
[   51.621460] WARNING: at arch/x86/kernel/smp.c:123 native_smp_send_reschedule+0x58/0x60()
[   51.629638] Modules linked in: ext2 vfat fat loop snd_hda_codec_hdmi usbhid snd_hda_codec_realtek coretemp kvm_intel kvm snd_hda_intel snd_hda_codec crc32_pclmul crc32c_intel ghash_clmulni_intel snd_hwdep snd_pcm aesni_intel sb_edac aes_x86_64 ehci_pci snd_page_alloc glue_helper snd_timer xhci_hcd snd iTCO_wdt iTCO_vendor_support ehci_hcd edac_core lpc_ich acpi_cpufreq lrw gf128mul ablk_helper cryptd mperf usbcore usb_common soundcore mfd_core dcdbas evdev pcspkr processor i2c_i801 button microcode
[   51.675581] CPU: 0 PID: 244 Comm: kworker/1:1 Tainted: G        W    3.10.0-rc1+ #10
[   51.683407] Hardware name: Dell Inc. Precision T3600/0PTTT9, BIOS A08 01/24/2013
[   51.690901] Workqueue: events od_dbs_timer
[   51.695069]  0000000000000009 ffff88043a2f5b68 ffffffff8161441c ffff88043a2f5ba8
[   51.702602]  ffffffff8103e540 0000000000000033 0000000000000001 ffff88043d5f8000
[   51.710136]  00000000ffff0ce1 0000000000000001 ffff88044fc4fc08 ffff88043a2f5bb8
[   51.717691] Call Trace:
[   51.720191]  [<ffffffff8161441c>] dump_stack+0x19/0x1b
[   51.725396]  [<ffffffff8103e540>] warn_slowpath_common+0x70/0xa0
[   51.731473]  [<ffffffff8103e58a>] warn_slowpath_null+0x1a/0x20
[   51.737378]  [<ffffffff81025628>] native_smp_send_reschedule+0x58/0x60
[   51.744013]  [<ffffffff81072cfd>] wake_up_nohz_cpu+0x2d/0xa0
[   51.749745]  [<ffffffff8104f6bf>] add_timer_on+0x8f/0x110
[   51.755214]  [<ffffffff8105f6fe>] __queue_delayed_work+0x16e/0x1a0
[   51.761470]  [<ffffffff8105f251>] ? try_to_grab_pending+0xd1/0x1a0
[   51.767724]  [<ffffffff8105f78a>] mod_delayed_work_on+0x5a/0xa0
[   51.773719]  [<ffffffff814f6b5d>] gov_queue_work+0x4d/0xc0
[   51.779271]  [<ffffffff814f60cb>] od_dbs_timer+0xcb/0x170
[   51.784734]  [<ffffffff8105e75d>] process_one_work+0x1fd/0x540
[   51.790634]  [<ffffffff8105e6f2>] ? process_one_work+0x192/0x540
[   51.796711]  [<ffffffff8105ef22>] worker_thread+0x122/0x380
[   51.802350]  [<ffffffff8105ee00>] ? rescuer_thread+0x320/0x320
[   51.808264]  [<ffffffff8106634a>] kthread+0xea/0xf0
[   51.813200]  [<ffffffff81066260>] ? flush_kthread_worker+0x150/0x150
[   51.819644]  [<ffffffff81623d5c>] ret_from_fork+0x7c/0xb0
[   51.918165] nouveau E[     DRM] GPU lockup - switching to software fbcon
[   51.930505]  [<ffffffff81066260>] ? flush_kthread_worker+0x150/0x150
[   51.936994] ---[ end trace f419538ada83b5c5 ]---

It was caused by the policy->cpus changed during the process of __gov_queue_work(), in other word, cpu offline happened.

This patch will use get/put_online_cpus() to prevent the offline happen inside __gov_queue_work(), after applied the patch, the warning is gone as Jiri tested:

        Link: https://lkml.org/lkml/2013/6/5/88
CC "Rafael J. Wysocki" <[email protected]>
CC Viresh Kumar <[email protected]>
Reported-by Borislav Petkov <[email protected]>
Reported-by Jiri Kosina <[email protected]>
Tested-by Jiri Kosina <[email protected]>
Signed-off-by Michael Wang <[email protected]>
Quoted 3 lines
---
 drivers/cpufreq/cpufreq_governor.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
Acked-by Viresh Kumar <[email protected]>
author
#2 lore raw

Hi, Viresh

On 06/05/2013 04:53 PM, Viresh Kumar wrote:
[snip]

Quoted 19 lines
Quoted 15 lines

It was caused by the policy->cpus changed during the process of __gov_queue_work(), in other word, cpu offline happened.

This patch will use get/put_online_cpus() to prevent the offline happen inside __gov_queue_work(), after applied the patch, the warning is gone as Jiri tested:

        Link: https://lkml.org/lkml/2013/6/5/88
CC "Rafael J. Wysocki" <[email protected]>
CC Viresh Kumar <[email protected]>
Reported-by Borislav Petkov <[email protected]>
Reported-by Jiri Kosina <[email protected]>
Tested-by Jiri Kosina <[email protected]>
Signed-off-by Michael Wang <[email protected]>
Quoted 3 lines
---
 drivers/cpufreq/cpufreq_governor.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
Quoted 1 line
Acked-by Viresh Kumar <[email protected]>

Thanks for your ack :)

Regards,
Michael Wang

Quoted 6 lines

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#3 lore raw
Quoted 23 lines · Michael Wang

Hi, Viresh

On 06/05/2013 04:53 PM, Viresh Kumar wrote:
[snip]

Quoted 19 lines
Quoted 18 lines

It was caused by the policy->cpus changed during the process of __gov_queue_work(), in other word, cpu offline happened.

This patch will use get/put_online_cpus() to prevent the offline happen inside __gov_queue_work(), after applied the patch, the warning is gone as Jiri tested:

        Link: https://lkml.org/lkml/2013/6/5/88
CC "Rafael J. Wysocki" <[email protected]>
CC Viresh Kumar <[email protected]>
Reported-by Borislav Petkov <[email protected]>
Reported-by Jiri Kosina <[email protected]>
Tested-by Jiri Kosina <[email protected]>
Signed-off-by Michael Wang <[email protected]>
---
 drivers/cpufreq/cpufreq_governor.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
Quoted 3 lines
Quoted 1 line
Acked-by Viresh Kumar <[email protected]>

Thanks for your ack :)

Queued up for 3.10.

Thanks,
Rafael

Signature · 2 lines
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.