cvs commit: src/sys/kern kern_mutex.c
scottl at samsco.org
Fri Sep 2 13:57:44 PDT 2005
John Baldwin wrote:
> jhb 2005-09-02 20:21:49 UTC
> FreeBSD src repository
> Modified files:
> sys/kern kern_mutex.c
> - Add an assertion to panic if one tries to call mtx_trylock() on a spin
Explaining exactly why this is bad, either in a commit log, in a
manpage, or in source code comments would be really nice. The pitfalls
are not immediately obvious to the casual observer.
> - Don't panic if a spin lock is held too long inside _mtx_lock_spin() if
> panicstr is set (meaning that we are already in a panic). Just keep
> spinning forever instead.
If panicstr is set, shouldn't all CPUs have already been sent an NMI?
This seems like a step backwards in reliability.
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