From: Tejun Heo tj@kernel.org
[ Upstream commit 15930da42f8981dc42c19038042947b475b19f47 ]
For wq_update_node_max_active(), @off_cpu of -1 indicates that no CPU is going down. The function was incorrectly calling cpumask_test_cpu() with -1 CPU leading to oopses like the following on some archs:
Unable to handle kernel paging request at virtual address ffff0002100296e0 .. pc : wq_update_node_max_active+0x50/0x1fc lr : wq_update_node_max_active+0x1f0/0x1fc ... Call trace: wq_update_node_max_active+0x50/0x1fc apply_wqattrs_commit+0xf0/0x114 apply_workqueue_attrs_locked+0x58/0xa0 alloc_workqueue+0x5ac/0x774 workqueue_init_early+0x460/0x540 start_kernel+0x258/0x684 __primary_switched+0xb8/0xc0 Code: 9100a273 35000d01 53067f00 d0016dc1 (f8607a60) ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Attempted to kill the idle task! ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---
Fix it.
Signed-off-by: Tejun Heo tj@kernel.org Reported-by: Marek Szyprowski m.szyprowski@samsung.com Reported-by: Nathan Chancellor nathan@kernel.org Tested-by: Nathan Chancellor nathan@kernel.org Link: http://lkml.kernel.org/r/91eacde0-df99-4d5c-a980-91046f66e612@samsung.com Fixes: 5797b1c18919 ("workqueue: Implement system-wide nr_active enforcement for unbound workqueues") Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/workqueue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 6b18926cf3523..6f7cb619aa5e4 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1500,7 +1500,7 @@ static void wq_update_node_max_active(struct workqueue_struct *wq, int off_cpu)
lockdep_assert_held(&wq->mutex);
- if (!cpumask_test_cpu(off_cpu, effective)) + if (off_cpu >= 0 && !cpumask_test_cpu(off_cpu, effective)) off_cpu = -1;
total_cpus = cpumask_weight_and(effective, cpu_online_mask);