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Date: Thu, 1 Oct 2015 06:43:17 +0800
From: Fengguang Wu <fengguang.wu@...el.com>
To: Kirill Tkhai <ktkhai@...n.com>
Cc: 0day robot <fengguang.wu@...el.com>, LKP <lkp@...org>,
LKML <linux-kernel@...r.kernel.org>,
"Huang, Ying" <ying.huang@...ux.intel.com>
Subject: [sched/fair] swapper/0/1 is trying to release lock
(rcu_read_lockrcu_read_lock) at:
Hi Kirill,
FYI, we applied your patch on v4.3-rc3 and find the below boot error.
commit 482eaa50ff81046e1e9f95af94176953d0743ec9
Author: Kirill Tkhai <ktkhai@...n.com>
AuthorDate: Mon Sep 28 18:36:28 2015 +0300
Commit: 0day robot <fengguang.wu@...el.com>
CommitDate: Mon Sep 28 23:38:23 2015 +0800
sched/fair: Skip wake_affine() for core siblings
On 28.09.2015 16:12, Mike Galbraith wrote:
> On Mon, 2015-09-28 at 13:28 +0300, Kirill Tkhai wrote:
>
>> Looks like, NAK may be better, because it saves L1 cache, while the patch always invalidates it.
>
> Yeah, bounce hurts more when there's no concurrency win waiting to be
> collected. This mixed load wasn't a great choice, but it turned out to
> be pretty interesting. Something waking a gaggle of waiters on a busy
> big socket should do very bad things.
>
>> Could you say, do you execute pgbench using just -cX -jY -T30 or something special? I've tried it,
>> but the dispersion of the results much differs from time to time.
>
> pgbench -T $testtime -j 1 -S -c $clients
Using -S the results stabilized. It looks like my db is enormous, and some problem with that. I will
investigate.
Thanks!
>>> Ok, that's what I want to see, full repeat.
>>> master = twiddle
>>> master+ = twiddle+patch
>>>
>>> concurrent tbench 4 + pgbench, 2 minutes per client count (i4790+smt)
>>> master master+
>>> pgbench 1 2 3 avg 1 2 3 avg comp
>>> clients 1 tps = 18599 18627 18532 18586 17480 17682 17606 17589 .946
>>> clients 2 tps = 32344 32313 32408 32355 25167 26140 23730 25012 .773
>>> clients 4 tps = 52593 51390 51095 51692 22983 23046 22427 22818 .441
>>> clients 8 tps = 70354 69583 70107 70014 66924 66672 69310 67635 .966
>>>
>>> Hrm... turn the tables, measure tbench while pgbench 4 client load runs endlessly.
>>>
>>> master master+
>>> tbench 1 2 3 avg 1 2 3 avg comp
>>> pairs 1 MB/s = 430 426 436 430 481 481 494 485 1.127
>>> pairs 2 MB/s = 1083 1085 1072 1080 1086 1090 1083 1086 1.005
>>> pairs 4 MB/s = 1725 1697 1729 1717 2023 2002 2006 2010 1.170
>>> pairs 8 MB/s = 2740 2631 2700 2690 3016 2977 3071 3021 1.123
>>>
>>> tbench without competition
>>> master master+ comp
>>> pairs 1 MB/s = 694 692 .997
>>> pairs 2 MB/s = 1268 1259 .992
>>> pairs 4 MB/s = 2210 2165 .979
>>> pairs 8 MB/s = 3586 3526 .983 (yawn, all within routine variance)
>>
>> Hm, it seems tbench with competition is better only because of a busy system makes tbench
>> processes be woken on the same cpu.
>
> Yeah. When box is really full, select_idle_sibling() (obviously) turns
> into a waste of cycles, but even as you approach that, especially when
> filling the box with identical copies of nearly fully synchronous high
> frequency localhost packet blasters, stacking is a win.
>
> What bent my head up a bit was the combined effect of making wake_wide()
> really keep pgbench from collapsing then adding the affine wakeup grant
> for tbench. It's not at all clear to me why 2,4 would be so demolished.
Mike, one more moment. wake_wide() and current logic confuses me a bit.
It makes us to decide if we want affine wakeup or not, but select_idle_sibling()
if a function is not for choosing this_cpu's llc domain only. We use it
for searching in prev_cpu llc domain too, and it seems we are not interested
in current flips in this case. Imagine a situation, when we share a mutex
with a task on another NUMA node. When the task is realising the mutex
it is waking us, but we definitelly won't use affine logic in this case.
We wake the wakee anywhere and loose hot cache. I changed the logic, and
tried pgbench 1:8. The results (I threw away 3 first iterations, because
they much differ with iter >= 4. Looks like, the reason is in uncached disk IO).
Before:
trans. | tps (i) | tps (e)
--------------------------------------
12098226 | 60491.067392 | 60500.886373
12030184 | 60150.874285 | 60160.654295
11882977 | 59414.829150 | 59424.830637
12020125 | 60100.579023 | 60111.600176
12161917 | 60809.547906 | 60827.321639
12154660 | 60773.249254 | 60783.085165
After:
trans. | tps (i) | tps (e)
--------------------------------------
12770407 | 63849.883578 | 63860.310019
12635366 | 63176.399769 | 63187.152569
12676890 | 63384.396440 | 63400.930755
12639949 | 63199.526330 | 63210.460753
12670626 | 63353.079951 | 63363.274143
12647001 | 63209.613698 | 63219.812331
I'm going to test other cases, but could you tell me (if you remember) are there reasons
we skip prev_cpu, like I described above? Some types of workloads etc.
+----------------------------------------------------------------------------------------+----------+------------+------------+
| | v4.3-rc3 | 482eaa50ff | 2c8c0a4d26 |
+----------------------------------------------------------------------------------------+----------+------------+------------+
| boot_successes | 150 | 41 | 0 |
| boot_failures | 0 | 51 | 24 |
| is_trying_to_release_lock(rcu_read_lockrcu_read_lock)at | 0 | 51 | 4 |
| BUG:sleeping_function_called_from_invalid_context_at_mm/slab.c | 0 | 51 | 4 |
| INFO:lockdep_is_turned_off | 0 | 51 | 4 |
| BUG:sleeping_function_called_from_invalid_context_at_kernel/rcu/tree.c | 0 | 26 | 2 |
| BUG:sleeping_function_called_from_invalid_context_at_arch/x86/mm/fault.c | 0 | 2 | |
| backtrace:spawn_ksoftirqd | 0 | 51 | 4 |
| backtrace:kernel_init_freeable | 0 | 51 | 4 |
| backtrace:getname_kernel | 0 | 51 | 4 |
| backtrace:run_init_process | 0 | 51 | 4 |
| BUG:sleeping_function_called_from_invalid_context_at_arch/x86/include/asm/uaccess.h | 0 | 7 | |
| BUG:sleeping_function_called_from_invalid_context_at_mm/vmstat.c | 0 | 5 | 3 |
| BUG:sleeping_function_called_from_invalid_context_at_kernel/locking/mutex.c | 0 | 17 | |
| BUG:sleeping_function_called_from_invalid_context_at_kernel/sched/completion.c | 0 | 2 | |
| BUG:sleeping_function_called_from_invalid_context_at_kernel/workqueue.c | 0 | 1 | |
| BUG:sleeping_function_called_from_invalid_context_at_kernel/cpu.c | 0 | 5 | 1 |
| BUG:sleeping_function_called_from_invalid_context_at_kernel/softirq.c | 0 | 1 | |
| BUG:sleeping_function_called_from_invalid_context_at_mm/page_alloc.c | 0 | 1 | |
| BUG:sleeping_function_called_from_invalid_context_at_kernel/events/core.c | 0 | 1 | |
| BUG:sleeping_function_called_from_invalid_context_at_arch/x86/include/asm/uaccess_32.h | 0 | 1 | |
| BUG:sleeping_function_called_from_invalid_context_at_fs/inode.c | 0 | 1 | |
| BUG:sleeping_function_called_from_invalid_context_at_arch/x86/mm/highmem_32.c | 0 | 1 | |
| backtrace:flush_to_ldisc | 0 | 1 | |
| BUG:sleeping_function_called_from_invalid_context_at_arch/x86/lib/usercopy_32.c | 0 | 1 | |
| backtrace:force_qs_rnp | 0 | 0 | 2 |
| backtrace:cache_reap | 0 | 0 | 4 |
| backtrace:vmstat_update | 0 | 0 | 3 |
| backtrace:vmstat_shepherd | 0 | 0 | 1 |
| BUG:kernel_boot_hang | 0 | 0 | 20 |
+----------------------------------------------------------------------------------------+----------+------------+------------+
[ 0.888548] -------------------------------------
[ 0.888548] -------------------------------------
[ 0.890637] swapper/0/1 is trying to release lock (
[ 0.890637] swapper/0/1 is trying to release lock (rcu_read_lockrcu_read_lock) at:
) at:
[ 0.893535] [<4109805b>] select_task_rq_fair+0x42b/0xa30
[ 0.893535] [<4109805b>] select_task_rq_fair+0x42b/0xa30
[ 0.895846] but there are no more locks to release!
[ 0.895846] but there are no more locks to release!
[ 0.897963]
[ 0.897963] other info that might help us debug this:
[ 0.897963]
[ 0.897963] other info that might help us debug this:
[ 0.901067] 3 locks held by swapper/0/1:
[ 0.901067] 3 locks held by swapper/0/1:
[ 0.902899] #0:
[ 0.902899] #0: ( (cpu_hotplug.lockcpu_hotplug.lock){......}){......}, at: , at: [<41063c7a>] get_online_cpus+0x2a/0x80
[<41063c7a>] get_online_cpus+0x2a/0x80
[ 0.906893] #1:
[ 0.906893] #1: ( (smpboot_threads_locksmpboot_threads_lock){......}){......}, at: , at: [<4108695d>] smpboot_register_percpu_thread_cpumask+0x5d/0x1d0
[<4108695d>] smpboot_register_percpu_thread_cpumask+0x5d/0x1d0
[ 0.911703] #2:
[ 0.911703] #2: ( (&p->pi_lock&p->pi_lock){......}){......}, at: , at: [<4108e603>] try_to_wake_up+0x23/0x320
[<4108e603>] try_to_wake_up+0x23/0x320
[ 0.915055]
[ 0.915055] stack backtrace:
[ 0.915055]
[ 0.915055] stack backtrace:
[ 0.917115] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.3.0-rc3-00001-g482eaa5 #1
[ 0.917115] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.3.0-rc3-00001-g482eaa5 #1
[ 0.924223] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
[ 0.924223] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
[ 0.928408] 41b28f7c
[ 0.928408] 41b28f7c 50625d0c 50625d0c 4137de12 4137de12 50622040 50622040 50625d2c 50625d2c 410b69ca 410b69ca 41a21090 41a21090 4109805b 4109805b
[ 0.933450] 4109805b
[ 0.933450] 4109805b ffffffff ffffffff af9dda70 af9dda70 50622574 50622574 50625d78 50625d78 410b8aae 410b8aae 00000000 00000000 00000000 00000000
[ 0.941080] 00000003
[ 0.941080] 00000003 00000000 00000000 00000000 00000000 00000002 00000002 00000046 00000046 50622040 50622040 00000003 00000003 506225ac 506225ac
[ 0.944747] Call Trace:
[ 0.944747] Call Trace:
[ 0.945907] [<4137de12>] dump_stack+0x4b/0x79
[ 0.945907] [<4137de12>] dump_stack+0x4b/0x79
[ 0.948570] [<410b69ca>] print_unlock_imbalance_bug+0xda/0xe0
[ 0.948570] [<410b69ca>] print_unlock_imbalance_bug+0xda/0xe0
[ 0.950975] [<4109805b>] ? select_task_rq_fair+0x42b/0xa30
[ 0.950975] [<4109805b>] ? select_task_rq_fair+0x42b/0xa30
[ 0.953365] [<4109805b>] ? select_task_rq_fair+0x42b/0xa30
[ 0.953365] [<4109805b>] ? select_task_rq_fair+0x42b/0xa30
[ 0.955919] [<410b8aae>] lock_release+0x27e/0x430
[ 0.955919] [<410b8aae>] lock_release+0x27e/0x430
[ 0.958209] [<4109805b>] ? select_task_rq_fair+0x42b/0xa30
[ 0.958209] [<4109805b>] ? select_task_rq_fair+0x42b/0xa30
[ 0.960926] [<4109806f>] select_task_rq_fair+0x43f/0xa30
[ 0.960926] [<4109806f>] select_task_rq_fair+0x43f/0xa30
[ 0.963567] [<4108e603>] ? try_to_wake_up+0x23/0x320
[ 0.963567] [<4108e603>] ? try_to_wake_up+0x23/0x320
[ 0.965903] [<410b73c6>] ? __lock_is_held+0x46/0x70
[ 0.965903] [<410b73c6>] ? __lock_is_held+0x46/0x70
[ 0.968065] [<4108e70e>] try_to_wake_up+0x12e/0x320
[ 0.968065] [<4108e70e>] try_to_wake_up+0x12e/0x320
[ 0.970129] [<4108e91f>] wake_up_process+0x1f/0x50
[ 0.970129] [<4108e91f>] wake_up_process+0x1f/0x50
[ 0.972188] [<410827ef>] kthread_create_on_node+0xaf/0x140
[ 0.972188] [<410827ef>] kthread_create_on_node+0xaf/0x140
[ 0.974608] [<410830be>] kthread_create_on_cpu+0x2e/0x60
[ 0.974608] [<410830be>] kthread_create_on_cpu+0x2e/0x60
[ 0.977100] [<410862a0>] ? sort_range+0x30/0x30
[ 0.977100] [<410862a0>] ? sort_range+0x30/0x30
[ 0.979251] [<410865f7>] __smpboot_create_thread+0x67/0xe0
[ 0.979251] [<410865f7>] __smpboot_create_thread+0x67/0xe0
[ 0.981886] [<410869ab>] smpboot_register_percpu_thread_cpumask+0xab/0x1d0
[ 0.981886] [<410869ab>] smpboot_register_percpu_thread_cpumask+0xab/0x1d0
[ 0.984986] [<41be5089>] ? trace_event_define_fields_softirq+0x1c/0x1c
[ 0.984986] [<41be5089>] ? trace_event_define_fields_softirq+0x1c/0x1c
[ 0.987866] [<41be50a6>] spawn_ksoftirqd+0x1d/0x27
[ 0.987866] [<41be50a6>] spawn_ksoftirqd+0x1d/0x27
[ 0.990119] [<4100044e>] do_one_initcall+0x7e/0x1d0
[ 0.990119] [<4100044e>] do_one_initcall+0x7e/0x1d0
[ 0.992251] [<41be5089>] ? trace_event_define_fields_softirq+0x1c/0x1c
[ 0.992251] [<41be5089>] ? trace_event_define_fields_softirq+0x1c/0x1c
[ 0.995097] [<410c3a17>] ? vprintk_default+0x37/0x40
[ 0.995097] [<410c3a17>] ? vprintk_default+0x37/0x40
[ 0.997301] [<4114bf41>] ? printk+0x17/0x19
[ 0.997301] [<4114bf41>] ? printk+0x17/0x19
[ 0.999302] [<41015eba>] ? print_cpu_info+0x8a/0x120
[ 0.999302] [<41015eba>] ? print_cpu_info+0x8a/0x120
[ 1.001692] [<41bdd77b>] ? native_smp_prepare_cpus+0x28c/0x2c8
[ 1.001692] [<41bdd77b>] ? native_smp_prepare_cpus+0x28c/0x2c8
[ 1.004237] [<41bcfc07>] kernel_init_freeable+0xf4/0x20c
[ 1.004237] [<41bcfc07>] kernel_init_freeable+0xf4/0x20c
[ 1.006939] [<417f8730>] kernel_init+0x10/0xe0
[ 1.006939] [<417f8730>] kernel_init+0x10/0xe0
[ 1.009210] [<4109029f>] ? schedule_tail+0x2f/0xa0
[ 1.009210] [<4109029f>] ? schedule_tail+0x2f/0xa0
[ 1.011599] [<41801831>] ret_from_kernel_thread+0x21/0x30
[ 1.011599] [<41801831>] ret_from_kernel_thread+0x21/0x30
[ 1.014045] [<417f8720>] ? rest_init+0xb0/0xb0
[ 1.014045] [<417f8720>] ? rest_init+0xb0/0xb0
[ 1.060738] CPU 1 irqstacks, hard=4fc0a000 soft=4fc0c000
[ 1.060738] CPU 1 irqstacks, hard=4fc0a000 soft=4fc0c000
[ 1.063030] x86: Booting SMP configuration:
git bisect start 2c8c0a4d26e74a8987dc59def3bed02cd3956692 9ffecb10283508260936b96022d4ee43a7798b4c --
git bisect bad 612cca0860f13d07ff14213738fb3c89c24ced8c # 11:25 0- 1 Merge 'linux-review/Kirill-Tkhai/Re-PATCH-sched-fair-Skip-wake_affine-for-core-siblings' into devel-catchup-201509291039
git bisect good e14fdfbf8c68b5504f7d96a7d7a5660ccc081edf # 11:57 47+ 47 Merge 'linux-review/Richard-Fitzgerald/regulator-arizona-add-support-for-WM8998-and-WM1814' into devel-catchup-201509291039
git bisect good 0434b9a84ff1b373a1cc167ee6ff340d31155f57 # 12:20 50+ 50 Merge 'linux-review/Paul-Gortmaker/net-core-make-sock_diag-c-explicitly-non-modular' into devel-catchup-201509291039
git bisect good 2411c8f8387f9fb1c964de2c8b9a3ebddc8b490b # 12:42 48+ 48 Merge 'linux-review/Lukasz-Skalski/Documentation-kdbus-use-valid-endpoint-names' into devel-catchup-201509291039
git bisect good df959084968cff10e79c79716f5f34ccf640d1a6 # 13:05 47+ 47 Merge 'linux-review/Luis-de-Bethencourt/staging-comedi-ni_tiocmd-remove-unused-code' into devel-catchup-201509291039
git bisect good ba9a39fc21229187dda68b90cbac55c17974a2da # 13:37 49+ 49 Merge 'linux-review/Liviu-Dudau/RESEND-PATCH-v3-net-next-sky2-use-random-address-if-EEPROM-is-bad' into devel-catchup-201509291039
git bisect good ed3f6ff4efb03739f5f102f3053c3657e52f682b # 14:04 47+ 47 Merge 'linux-review/Kishon-Vijay-Abraham-I/DRA72-DRA74-Add-2-lane-support' into devel-catchup-201509291039
git bisect bad 482eaa50ff81046e1e9f95af94176953d0743ec9 # 14:04 0- 51 sched/fair: Skip wake_affine() for core siblings
# first bad commit: [482eaa50ff81046e1e9f95af94176953d0743ec9] sched/fair: Skip wake_affine() for core siblings
git bisect good 9ffecb10283508260936b96022d4ee43a7798b4c # 14:08 150+ 0 Linux 4.3-rc3
# extra tests on HEAD of linux-devel/devel-catchup-201509291039
git bisect bad 2c8c0a4d26e74a8987dc59def3bed02cd3956692 # 14:08 0- 24 0day head guard for 'devel-catchup-201509291039'
# extra tests on tree/branch linux-devel/revert-482eaa50ff81046e1e9f95af94176953d0743ec9-482eaa50ff81046e1e9f95af94176953d0743ec9
git bisect good 3a51398efa3a8362652971306175b65774480e80 # 14:25 151+ 0 Revert "sched/fair: Skip wake_affine() for core siblings"
# extra tests on tree/branch linus/master
git bisect good 097f70b3c4d84ffccca15195bdfde3a37c0a7c0f # 14:48 151+ 0 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
# extra tests on tree/branch linux-next/master
git bisect good 0293645856ec527639b5902f021fa5aeba93e305 # 14:55 151+ 0 Add linux-next specific files for 20150929
This script may reproduce the error.
----------------------------------------------------------------------------
#!/bin/bash
kernel=$1
initrd=quantal-core-i386.cgz
wget --no-clobber https://github.com/fengguang/reproduce-kernel-bug/raw/master/initrd/$initrd
kvm=(
qemu-system-x86_64
-enable-kvm
-cpu kvm64
-kernel $kernel
-initrd $initrd
-m 300
-smp 2
-device e1000,netdev=net0
-netdev user,id=net0
-boot order=nc
-no-reboot
-watchdog i6300esb
-rtc base=localtime
-serial stdio
-display none
-monitor null
)
append=(
hung_task_panic=1
earlyprintk=ttyS0,115200
systemd.log_level=err
debug
apic=debug
sysrq_always_enabled
rcupdate.rcu_cpu_stall_timeout=100
panic=-1
softlockup_panic=1
nmi_watchdog=panic
oops=panic
load_ramdisk=2
prompt_ramdisk=0
console=ttyS0,115200
console=tty0
vga=normal
root=/dev/ram0
rw
drbd.minor_count=8
)
"${kvm[@]}" --append "${append[*]}"
----------------------------------------------------------------------------
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/lkp Intel Corporation
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View attachment ".config" of type "text/plain" (96028 bytes)
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