it is very common wq->dfl_pwq->refcnt > 1. [ 7.939873] WARNING: at kernel/workqueue.c:4201 destroy_workqueue+0x6a/0x13e() [ 7.943601] Hardware name: 4286C12 [ 7.947250] Modules linked in: sdhci_pci sdhci mmc_core usb_storage i915 drm_kms_helper drm i2c_algo_bit i2c_core video [ 7.951313] Pid: 361, comm: umount Not tainted 3.9.0-rc5+ #29 [ 7.955309] Call Trace: [ 7.959346] [<c04314a7>] warn_slowpath_common+0x7c/0x93 [ 7.963506] [<c044796a>] ? destroy_workqueue+0x6a/0x13e [ 7.967748] [<c044796a>] ? destroy_workqueue+0x6a/0x13e [ 7.971981] [<c04314e0>] warn_slowpath_null+0x22/0x24 [ 7.976383] [<c044796a>] destroy_workqueue+0x6a/0x13e [ 7.980875] [<c056dc01>] ext4_put_super+0x43/0x2c4 [ 7.985407] [<c050bd48>] ? dispose_list+0x28/0x32 [ 7.989987] [<c050c652>] ? evict_inodes+0xcf/0xd7 [ 7.994509] [<c04fb7b8>] generic_shutdown_super+0x4b/0xb9 [ 7.999130] [<c04fb848>] kill_block_super+0x22/0x60 [ 8.003594] [<c04fb960>] deactivate_locked_super+0x2f/0x56 [ 8.008077] [<c04fc41b>] deactivate_super+0x2e/0x31 [ 8.012523] [<c050f1e6>] mntput_no_expire+0x103/0x108 [ 8.017050] [<c050fdce>] sys_umount+0x2a2/0x2c4 [ 8.021429] [<c050fe0e>] sys_oldumount+0x1e/0x20 [ 8.025678] [<c085ba4d>] sysenter_do_call+0x12/0x38
Signed-off-by: Lai Jiangshan <la...@cn.fujitsu.com> --- kernel/workqueue.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 3f33077..f015c38 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -4198,7 +4198,7 @@ void destroy_workqueue(struct workqueue_struct *wq) } } - if (WARN_ON(pwq->refcnt > 1) || + if (WARN_ON((pwq != wq->dfl_pwq) && (pwq->refcnt > 1)) || WARN_ON(pwq->nr_active) || WARN_ON(!list_empty(&pwq->delayed_works))) { mutex_unlock(&wq->mutex); -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/