On Tuesday 19 October 2004 05:25 pm, Julian Elischer wrote: > John Baldwin wrote: > >On Tuesday 19 October 2004 12:01 pm, Kris Kennaway wrote: > >>On Tue, Oct 19, 2004 at 09:13:26AM -0400, Robert Huff wrote: > >>>Brian Fundakowski Feldman writes: > >>>> You should never not run with WITNESS_SKIPSPIN if you use > >>>> modules. Any spin mutexes not listed statically in the witness > >>>> code will cause your machine to immediately panic. > >>> > >>> If this is true (and I'm not disputing it), shouldn't it be > >>>noted in GENERIC and/or NOTES? For that matter, what's the penalty > >>>for not automatically including it as part of WITNESS? > >> > >>Sometimes you don't want to use it, e.g. if you actually want to trace > >>spinlock operations with witness. > > > >True spin mutexes should be rarely used anyways, so I don't think modules > >needing spin mutexes is all that big of an issue. Almost all mutexes > > should just be regular mutexes. > > netgraph uses a spin mutex for it's node locks This is likely a bug, esp. given that normal mutexes adaptively spin when it is advantageous to do so. :) -- John Baldwin <jhb_at_FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/Received on Tue Oct 19 2004 - 19:50:27 UTC
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