Re: [PATCH] lockdep: suggest the fix for "lockdep bfs error:-1" on print_bfs_bug

Luis Claudio R. Goncalves
2024-07-29T16:53:40Z

On Fri, Jul 26, 2024 at 02:24:28PM -0700, Boqun Feng wrote:
> On Thu, Jul 25, 2024 at 03:45:57PM -0300, Luis Claudio R. Goncalves wrote:
> > When lockdep fails while performing the Breadth-first-search operation
> > due to lack of memory, hint that increasing the value of the configuration
> > switch LOCKDEP_CIRCULAR_QUEUE_BITS should fix the warning.
> >
> > Preface the scary bactrace with the suggestion:
> >
> > [ 163.849242] Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning:
> > [ 163.849248] ------------[ cut here ]------------
> > [ 163.849250] lockdep bfs error:-1
> > [ 163.849263] WARNING: CPU: 24 PID: 2454 at kernel/locking/lockdep.c:2091 print_bfs_bug+0x27/0x40
> > ...
> >
> > Signed-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
> > ---
> > kernel/locking/lockdep.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
> > index 58c88220a478a..1cf6d9fdddc9c 100644
> > --- a/kernel/locking/lockdep.c
> > +++ b/kernel/locking/lockdep.c
> > @@ -2067,6 +2067,9 @@ static noinline void print_bfs_bug(int ret)
> > /*
> > * Breadth-first-search failed, graph got corrupted?
> > */
> > + if (ret == BFS_EQUEUEFULL)
>
> This line has an extra space after "ret", but otherwise it looks fine.

Should I send a v2 of the patch with the extra whitespace removed?

Luis

> Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
>
> Regards,
> Boqun
>
> > + pr_warn("Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning:\n");
> > +
> > WARN(1, "lockdep bfs error:%d\n", ret);
> > }
> >
> > --
> > 2.45.2
> >
>
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