On 11/3/10 10:52 AM, Julian Elischer wrote: > On 11/3/10 10:17 AM, John Baldwin wrote: >> On Wednesday, November 03, 2010 1:04:13 pm mdf_at_freebsd.org wrote: >>> >>> So a MTX_DEF is okay in that environment? >> Yes. In fact, the reason to have threads for interrupt handlers is >> to allow >> interrupt handlers to use non-spin locks that block when the lock >> is held. >> >> MTX_SPIN locks are generally not needed in device drivers. The >> only reason a >> driver would use one is if it used a filter handler which does not >> run in a >> threaded context. > oops a line got deleted I think.. > It should be noted that in the case where you really just want to > spin a few > instructions because some other thread is accessing a structure you > want, ... then the BTX_DEF code will spin for a short while before ... > descheduling you. so you don't always incur the scheduling overhead. > > _______________________________________________ > freebsd-current_at_freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to > "freebsd-current-unsubscribe_at_freebsd.org" >Received on Wed Nov 03 2010 - 21:01:20 UTC
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