Messages in this thread | | | Date | Tue, 22 Mar 2016 14:52:43 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [RFC][PATCH v5 1/2] printk: Make printk() completely async |
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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
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