On (03/22/16 11:13), Byungchul Park wrote:
[..]
what about a "normal" case, when things are not going to explode printk(),
but we have several lockups on the same lock (which is probably more
likely than printk recursion)?
suppose:
- there are 8 CPUs on the system
- 1 cpus owns the spin_lock for too long
- 4 cpus are trying to lock the spin_lock w/o any success
- so all 4 trigger spin_dump.
what we have at the moment, is that all 4 CPUs will report a lockup,
but with this static pointer only X (between 1 and 4, depending on the
timing; on how fast spin_dump() will return (logbuf lock can
be busy for a while); etc.) CPUs will do so.
-ss
