On Fri, Sep 17, 2010 at 9:16 AM, Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote: > > > Not really ... look at the code path (in scsi.c:scsi_dispatch_cmd()). > > We take the lock, then get the serial number (that would likley have to > > be replaced with an atomic), check the state, call trace, call > > An atomic unfortunately usually doesn't scale much better than a spinlock. > I suspect serials would need to be made optional, e.g. > computing them lazily if really needed. We should be careful that the command processing order for commands issued by different threads is not altered by removing the host lock, at least for those SCSI commands where in-order processing matters. There might be better solutions than a serial number though. Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
