From mboxrd@z Thu Jan 1 00:00:00 1970 From: Uma Krishnan Subject: [PATCH 7/7] cxlflash: Increase cmd_per_lun for better throughput Date: Fri, 4 Mar 2016 15:55:20 -0600 Message-ID: <1457128520-53056-7-git-send-email-ukrishn@linux.vnet.ibm.com> References: <1457128424-53017-1-git-send-email-ukrishn@linux.vnet.ibm.com> <1457128520-53056-1-git-send-email-ukrishn@linux.vnet.ibm.com> Return-path: Received: from e17.ny.us.ibm.com ([129.33.205.207]:43190 "EHLO e17.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759976AbcCDV6o (ORCPT ); Fri, 4 Mar 2016 16:58:44 -0500 Received: from localhost by e17.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 4 Mar 2016 16:58:43 -0500 Received: from b01cxnp22035.gho.pok.ibm.com (b01cxnp22035.gho.pok.ibm.com [9.57.198.25]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id C9C8CC90043 for ; Fri, 4 Mar 2016 16:58:38 -0500 (EST) Received: from d01av05.pok.ibm.com (d01av05.pok.ibm.com [9.56.224.195]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u24LwfEM31654092 for ; Fri, 4 Mar 2016 21:58:41 GMT Received: from d01av05.pok.ibm.com (localhost [127.0.0.1]) by d01av05.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u24LsKFc031537 for ; Fri, 4 Mar 2016 16:54:24 -0500 In-Reply-To: <1457128520-53056-1-git-send-email-ukrishn@linux.vnet.ibm.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org, James Bottomley , "Martin K. Petersen" , "Matthew R. Ochs" , "Manoj N. Kumar" Cc: linuxppc-dev@lists.ozlabs.org, Brian King , Ian Munsie , Andrew Donnellan , Frederic Barrat , Christophe Lombard From: "Manoj N. Kumar" With the current value of cmd_per_lun at 16, the throughput over a single adapter is limited to around 150kIOPS. Increase the value of cmd_per_lun to 256 to improve throughput. With this change a single adapter is able to attain close to the maximum throughput (380kIOPS). Also change the number of RRQ entries that can be queued. Signed-off-by: Manoj N. Kumar --- drivers/scsi/cxlflash/common.h | 8 +++++--- drivers/scsi/cxlflash/main.c | 2 +- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/cxlflash/common.h b/drivers/scsi/cxlflash/common.h index 5ada926..a8ac4c0 100644 --- a/drivers/scsi/cxlflash/common.h +++ b/drivers/scsi/cxlflash/common.h @@ -34,7 +34,6 @@ extern const struct file_operations cxlflash_cxl_fops; sectors */ -#define NUM_RRQ_ENTRY 16 /* for master issued cmds */ #define MAX_RHT_PER_CONTEXT (PAGE_SIZE / sizeof(struct sisl_rht_entry)) /* AFU command retry limit */ @@ -48,9 +47,12 @@ extern const struct file_operations cxlflash_cxl_fops; index derivation */ -#define CXLFLASH_MAX_CMDS 16 +#define CXLFLASH_MAX_CMDS 256 #define CXLFLASH_MAX_CMDS_PER_LUN CXLFLASH_MAX_CMDS +/* RRQ for master issued cmds */ +#define NUM_RRQ_ENTRY CXLFLASH_MAX_CMDS + static inline void check_sizes(void) { @@ -149,7 +151,7 @@ struct afu_cmd { struct afu { /* Stuff requiring alignment go first. */ - u64 rrq_entry[NUM_RRQ_ENTRY]; /* 128B RRQ */ + u64 rrq_entry[NUM_RRQ_ENTRY]; /* 2K RRQ */ /* * Command & data for AFU commands. */ diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index 0f062a4..3879b46 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -2253,7 +2253,7 @@ static struct scsi_host_template driver_template = { .eh_device_reset_handler = cxlflash_eh_device_reset_handler, .eh_host_reset_handler = cxlflash_eh_host_reset_handler, .change_queue_depth = cxlflash_change_queue_depth, - .cmd_per_lun = 16, + .cmd_per_lun = CXLFLASH_MAX_CMDS_PER_LUN, .can_queue = CXLFLASH_MAX_CMDS, .this_id = -1, .sg_tablesize = SG_NONE, /* No scatter gather support */ -- 2.1.0