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| author | Tejun Heo <tj@kernel.org> | 2013-05-10 11:10:17 -0700 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2013-05-10 11:10:17 -0700 |
| commit | d3251859168b0b12841e1b90d6d768ab478dc23d (patch) | |
| tree | ccfb1c9c2da7e67d8b9d3ab9a0027a556f0a4fec /kernel/workqueue.c | |
| parent | 2dbd3cac87250a0d44e07acc86c4224a08522709 (diff) | |
| download | linux-d3251859168b0b12841e1b90d6d768ab478dc23d.tar.gz linux-d3251859168b0b12841e1b90d6d768ab478dc23d.tar.bz2 linux-d3251859168b0b12841e1b90d6d768ab478dc23d.zip | |
workqueue: workqueue_congested() shouldn't translate WORK_CPU_UNBOUND into node number
df2d5ae499 ("workqueue: map an unbound workqueues to multiple per-node
pool_workqueues") made unbound workqueues to map to multiple per-node
pool_workqueues and accordingly updated workqueue_contested() so that,
for unbound workqueues, it maps the specified @cpu to the NUMA node
number to obtain the matching pool_workqueue to query the congested
state.
Before this change, workqueue_congested() ignored @cpu for unbound
workqueues as there was only one pool_workqueue and some users
(fscache) called it with WORK_CPU_UNBOUND. After the commit, this
causes the following oops as WORK_CPU_UNBOUND gets translated to
garbage by cpu_to_node().
BUG: unable to handle kernel paging request at ffff8803598d98b8
IP: [<ffffffff81043b7e>] unbound_pwq_by_node+0xa1/0xfa
PGD 2421067 PUD 0
Oops: 0000 [#1] SMP
CPU: 1 PID: 2689 Comm: cat Tainted: GF 3.9.0-fsdevel+ #4
task: ffff88003d801040 ti: ffff880025806000 task.ti: ffff880025806000
RIP: 0010:[<ffffffff81043b7e>] [<ffffffff81043b7e>] unbound_pwq_by_node+0xa1/0xfa
RSP: 0018:ffff880025807ad8 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff8800388a2400 RCX: 0000000000000003
RDX: ffff880025807fd8 RSI: ffffffff81a31420 RDI: ffff88003d8016e0
RBP: ffff880025807ae8 R08: ffff88003d801730 R09: ffffffffa00b4898
R10: ffffffff81044217 R11: ffff88003d801040 R12: 0000000064206e97
R13: ffff880036059d98 R14: ffff880038cc8080 R15: ffff880038cc82d0
FS: 00007f21afd9c740(0000) GS:ffff88003d100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff8803598d98b8 CR3: 000000003df49000 CR4: 00000000000007e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Stack:
ffff8800388a2400 0000000000000002 ffff880025807b18 ffffffff810442ce
ffffffff81044217 ffff880000000002 ffff8800371b4080 ffff88003d112ec0
ffff880025807b38 ffffffffa00810b0 ffff880036059d88 ffff880036059be8
Call Trace:
[<ffffffff810442ce>] workqueue_congested+0xb7/0x12c
[<ffffffffa00810b0>] fscache_enqueue_object+0xb2/0xe8 [fscache]
[<ffffffffa007facd>] __fscache_acquire_cookie+0x3b9/0x56c [fscache]
[<ffffffffa00ad8fe>] nfs_fscache_set_inode_cookie+0xee/0x132 [nfs]
[<ffffffffa009e112>] do_open+0x9/0xd [nfs]
[<ffffffff810e804a>] do_dentry_open+0x175/0x24b
[<ffffffff810e8298>] finish_open+0x41/0x51
Fix it by using smp_processor_id() if @cpu is WORK_CPU_UNBOUND.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: David Howells <dhowells@redhat.com>
Tested-and-Acked-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'kernel/workqueue.c')
| -rw-r--r-- | kernel/workqueue.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 4aa9f5bc6b2d..1ae602809efb 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -4311,6 +4311,12 @@ bool current_is_workqueue_rescuer(void) * no synchronization around this function and the test result is * unreliable and only useful as advisory hints or for debugging. * + * If @cpu is WORK_CPU_UNBOUND, the test is performed on the local CPU. + * Note that both per-cpu and unbound workqueues may be associated with + * multiple pool_workqueues which have separate congested states. A + * workqueue being congested on one CPU doesn't mean the workqueue is also + * contested on other CPUs / NUMA nodes. + * * RETURNS: * %true if congested, %false otherwise. */ @@ -4321,6 +4327,9 @@ bool workqueue_congested(int cpu, struct workqueue_struct *wq) rcu_read_lock_sched(); + if (cpu == WORK_CPU_UNBOUND) + cpu = smp_processor_id(); + if (!(wq->flags & WQ_UNBOUND)) pwq = per_cpu_ptr(wq->cpu_pwqs, cpu); else |