Re: [rbtree_test_init] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper:1]

[Fengguang Wu]

On Tue, Nov 21, 2017 at 01:59:13PM -0800, Andrew Morton wrote:
> On Tue, 21 Nov 2017 19:10:22 +0800 Fengguang Wu <fengguang.wu@xxxxxxxxx> wrote:
>
> > Hello,
> >
> > FYI this happens in mainline kernel 4.14.0-03453-ge37e0ee.
> > It at least dates back to v4.1 .
> >
> > It occurs in 2 out of 2 boots.
> >
> > [  140.043368] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper:1]
> > ...
> > [  140.044140] Call Trace:
> > [  140.044140]  __asan_loadN+0x19/0x21
> > [  140.044140]  ftrace_likely_update+0x32/0xc3:
> > ftrace_likely_update at kernel/trace/trace_branch.c:209
> > [  140.044140]  ? augment_recompute+0x14b/0x14b:
> > augment_callbacks_rotate at lib/rbtree_test.c:97
> > [  140.044140]  __rb_insert_augmented+0x8d/0x639:
> > __rb_insert at lib/rbtree.c:110
> >   (inlined by) __rb_insert_augmented at lib/rbtree.c:495
> > [  140.044140]  rbtree_test_init+0xbfb/0x1407:
> > rb_insert_augmented_cached at include/linux/rbtree_augmented.h:70
> >   (inlined by) insert_augmented_cached at lib/rbtree_test.c:148
> >   (inlined by) rbtree_test_init at lib/rbtree_test.c:371
> > [  140.044140]  ? glob_init+0x23f/0x23f:
> > rbtree_test_init at lib/rbtree_test.c:245
>
> Does that kernel include 0b548e33e6cb2bf ("lib/rbtree-test: lower
> default params")?  If so, perhaps some cond_resched() sprinkling is
> needed?

Ah I just tested 0b548e33e6cb2bf and it's fine there. 0b548e33e6cb2bf
is merged after e37e0ee0190 in this report, so it indicates a fixed
error. Sorry for the noise!

Regards,
Fengguang