From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Tejun Heo <htejun@gmail.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Abdul Haleem <abdhalee@linux.vnet.ibm.com>,
Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
"Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
Subject: [PATCH 0/2] Fix CPU Online handling for unbounded worker threads
Date: Tue, 7 Jun 2016 20:44:01 +0530 [thread overview]
Message-ID: <cover.1465311052.git.ego@linux.vnet.ibm.com> (raw)
In-Reply-To: <5756BE20.3040208@linux.vnet.ibm.com>
Hi,
This patchset fixes a couple of issues in the CPU_ONLINE notification
handling for the workqueues with respect to unbounded worker threads.
Patch 1 ensures that the affinity of a unbound worker thread
associated with a node whose very first CPU has come online is set
correctly. In the existing code path we will never call
set_cpus_allowed_ptr() for unbound worker threads that have been
created on a CPU Online operation after boot.
Patch 2 fixes the following WARN_ON() reported by Abdul when
set_cpus_allowed_ptr() for an unbound worker thread is invoked when
only one of the CPUs in its cpumask is online but not yet active.
------------[ cut here ]------------
WARNING: CPU: 40 PID: 248 at kernel/sched/core.c:1166 __set_cpus_allowed_ptr+0x21c/0x290
Modules linked in:
CPU: 40 PID: 248 Comm: cpuhp/40 Not tainted 4.6.0-autotest #1
task: c000000f27284200 ti: c000000f273fc000 task.ti: c000000f273fc000
NIP: c00000000010488c LR: c000000000104874 CTR: 0000000000000000
REGS: c000000f273ff7d0 TRAP: 0700 Not tainted (4.6.0-autotest)
MSR: 9000000100029033 <SF,HV,EE,ME,IR,DR,RI,LE,TM[E]> CR: 28002804 XER: 20000000
CFAR: c0000000005b0888 SOFTE: 0
GPR00: c00000000010478c c000000f273ffa50 c0000000013ce400 0000000000000000
GPR04: c00000000140ed98 0000000000000800 c0000007f64d9408 0000000000000000
GPR08: 0000000000000000 0000000000000028 c00000000140ee90 0000000000000020
GPR12: 0000000000002200 c00000000fb96800 c0000000000f44a8 c0000007fa158480
GPR16: c0000007fc621a70 c000000f2721f800 0000000000000000 0000000000000001
GPR20: c000000001571ef0 0000000000000000 c00000000134879f c0000000012bc510
GPR24: 0000010000000000 0000000000000000 c00000000140ea98 c0000007f64d9408
GPR28: c0000007fbc21c00 ffffffffffffffea 0000000000000000 c000000f27280000
NIP [c00000000010488c] __set_cpus_allowed_ptr+0x21c/0x290
LR [c000000000104874] __set_cpus_allowed_ptr+0x204/0x290
Call Trace:
[c000000f273ffa50] [c00000000010478c] __set_cpus_allowed_ptr+0x11c/0x290 (unreliable)
[c000000f273ffac0] [c0000000000ed4b0] workqueue_cpu_up_callback+0x2c0/0x470
[c000000f273ffb70] [c0000000000f5c58] notifier_call_chain+0x98/0x100
[c000000f273ffbc0] [c0000000000c5ed0] __cpu_notify+0x70/0xe0
[c000000f273ffc00] [c0000000000c6028] notify_online+0x38/0x50
[c000000f273ffc30] [c0000000000c5214] cpuhp_invoke_callback+0x84/0x250
[c000000f273ffc90] [c0000000000c562c] cpuhp_up_callbacks+0x5c/0x120
[c000000f273ffce0] [c0000000000c64d4] cpuhp_thread_fun+0x184/0x1c0
[c000000f273ffd20] [c0000000000fa050] smpboot_thread_fn+0x290/0x2a0
[c000000f273ffd80] [c0000000000f45b0] kthread+0x110/0x130
[c000000f273ffe30] [c000000000009570] ret_from_kernel_thread+0x5c/0x6c
Instruction dump:
419eff3c 3d420004 38a00800 388a0998 7f63db78 484abfa1 60000000 2fa30000
409eff1c 813f0378 2f890001 419eff10 <0fe00000> 4bffff08 60000000 60000000
---[ end trace cbc1c5cfbc9591d0 ]---
The patches are based on 4.7-rc2. I have tested the patches on a
multi-node x86_64 and a ppc64
Gautham R. Shenoy (2):
workqueue: Move wq_update_unbound_numa() to the beginning of
CPU_ONLINE
workqueue:Fix affinity of an unbound worker of a node with 1 online
CPU
kernel/workqueue.c | 27 +++++++++++++++++++--------
1 file changed, 19 insertions(+), 8 deletions(-)
--
1.9.3
next prev parent reply other threads:[~2016-06-07 15:14 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-19 10:57 WARNING at kernel/sched/core.c:1166 while booting 4.6.0 mainline on ppc64le bare metal abdhalee
2016-05-19 12:34 ` Gavin Shan
2016-05-26 15:11 ` Gautham R Shenoy
2016-06-07 12:29 ` Abdul Haleem
2016-06-07 15:14 ` Gautham R. Shenoy [this message]
2016-06-07 15:14 ` [PATCH 1/2] workqueue: Move wq_update_unbound_numa() to the beginning of CPU_ONLINE Gautham R. Shenoy
2016-06-15 15:53 ` Tejun Heo
2016-06-15 19:28 ` Gautham R Shenoy
2016-06-16 19:35 ` Tejun Heo
2016-06-21 14:12 ` Gautham R Shenoy
2016-06-21 15:36 ` Tejun Heo
2016-06-21 19:37 ` Peter Zijlstra
2016-06-21 19:43 ` Tejun Heo
2016-06-21 19:47 ` Peter Zijlstra
2016-06-22 5:15 ` Gautham R Shenoy
2016-06-07 15:14 ` [PATCH 2/2] workqueue:Fix affinity of an unbound worker of a node with 1 online CPU Gautham R. Shenoy
2016-06-08 6:03 ` Abdul Haleem
2016-06-14 11:22 ` Peter Zijlstra
2016-06-15 10:19 ` Gautham R Shenoy
2016-06-15 11:32 ` Peter Zijlstra
2016-06-15 12:50 ` Gautham R Shenoy
2016-06-15 13:14 ` Peter Zijlstra
2016-06-15 16:01 ` Tejun Heo
2016-06-16 12:11 ` Michael Ellerman
2016-06-16 12:45 ` Peter Zijlstra
2016-06-16 19:39 ` Tejun Heo
2016-06-17 1:49 ` Michael Ellerman
2016-07-15 5:27 ` Gautham R Shenoy
2016-07-15 5:30 ` Michael Ellerman
[not found] ` <57887507.911f240a.687de.08c5SMTPIN_ADDED_BROKEN@mx.google.com>
2016-07-15 12:10 ` Tejun Heo
2016-06-13 5:44 ` [PATCH 0/2] Fix CPU Online handling for unbounded worker threads Gautham R Shenoy
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