Hi Matthew, On Thu, 2014-03-27 at 16:40 -0400, Matthew Wilcox wrote: > The host lock is a serious scalability problem on 2-socket and larger > systems which are doing a lot of I/O. Before removing the temporary > usgae of DEF_SCSI_QCMD, we need to remove all uses of serial_number. > > An unrelated performance issue is that reusing the most recent > driver-specific data structure to track the I/O instead of the least > recently used keeps the cache-hot lines in use, which is a nice > performance improvement. It's already present in the mpt3sas driver, > it just didn't make it into the fusion or mpt2sas drivers yet. > > Matthew Wilcox (7): > mpt3sas: Remove uses of serial_number > mpt3sas: Remove use of DEF_SCSI_QCMD > mpt2sas: Remove uses of serial_number > mpt2sas: Remove use of DEF_SCSI_QCMD > mpt2sas: Add free smids to the head, not tail of list > fusion: Add free msg frames to the head, not tail of list > fusion: Remove use of DEF_SCSI_QCMD > > +1 to this long overdue series to enable host_lock-less mode with mpt*sas + fusion. (CC'ing LSI folks + jejb) Reviewed-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx> -- 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
