Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 31 Jan 2024 08:45:23 +0100 | Subject | Re: [PATCH v4 09/10] workqueue: Implement system-wide nr_active enforcement for unbound workqueues | From | Marek Szyprowski <> |
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On 31.01.2024 06:01, Tejun Heo wrote: > From: Tejun Heo <tj@kernel.org> > Date: Tue, 30 Jan 2024 18:55:55 -1000 > Subject: [PATCH] workqueue: Don't call cpumask_test_cpu() with -1 CPU in > wq_update_node_max_active() > > 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")
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
> --- > Applied to wq/for-6.9. > > Thanks. > > kernel/workqueue.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/workqueue.c b/kernel/workqueue.c > index 9221a4c57ae1..31c1373505d8 100644 > --- a/kernel/workqueue.c > +++ b/kernel/workqueue.c > @@ -1510,7 +1510,7 @@ 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);
Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
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