hpsa: optimize cmd_alloc function by remembering last allocation
Empirically, this improves performance slightly (~2% max IOPS) by
allowing cmd_alloc to remember where it left off searching for
free commands between calls instead of always starting its search
at command 0.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index 679e4d2..981479a1 100644
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -133,6 +133,7 @@
struct CfgTable __iomem *cfgtable;
int interrupts_enabled;
int max_commands;
+ int last_allocation;
atomic_t commands_outstanding;
# define PERF_MODE_INT 0
# define DOORBELL_INT 1