From: Jens Axboe <axboe@kernel.dk>
Date: Fri, 11 May 2018 16:07:50 +0000 (-0600)
Subject: ahci: enable full queue depth of 32
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=refs%2Fheads%2Flibata-qd32;p=linux-2.6-block.git

ahci: enable full queue depth of 32

This changes the AHCI queue depth from 31 to 32, as libata now
fully supports it. Now regular IO requests can utilize the full
tag space of SATA, not just 31. For IOPS constrained workloads,
this can result in a ~3% bump in performance.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 824bd399f02e..1609ebab4e23 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -390,7 +390,7 @@ extern struct device_attribute *ahci_sdev_attrs[];
  */
 #define AHCI_SHT(drv_name)						\
 	ATA_NCQ_SHT(drv_name),						\
-	.can_queue		= AHCI_MAX_CMDS - 1,			\
+	.can_queue		= AHCI_MAX_CMDS,			\
 	.sg_tablesize		= AHCI_MAX_SG,				\
 	.dma_boundary		= AHCI_DMA_BOUNDARY,			\
 	.shost_attrs		= ahci_shost_attrs,			\