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lockdep: suggest the fix for "lockdep bfs error:-1" on print_bfs_bug

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When lockdep fails while performing the Breadth-first-search operation
due to lack of memory, hint that increasing the value of the config
switch LOCKDEP_CIRCULAR_QUEUE_BITS should fix the warning.

Preface the scary backtrace 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>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/Zqkmy0lS-9Sw0M9j@uudg.org
This commit is contained in:
Luis Claudio R. Goncalves 2024-07-30 14:45:47 -03:00 committed by Peter Zijlstra
parent dce2a22476
commit 7886a61ebc
1 changed files with 3 additions and 0 deletions
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3
kernel/locking/lockdep.c
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@ -2067,6 +2067,9 @@ static noinline void print_bfs_bug(int ret)
/* /*
* Breadth-first-search failed, graph got corrupted? * Breadth-first-search failed, graph got corrupted?
*/ */
if (ret == BFS_EQUEUEFULL)
pr_warn("Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning:\n");
WARN(1, "lockdep bfs error:%d\n", ret); WARN(1, "lockdep bfs error:%d\n", ret);
} }