From d380f55503ed28461422546900baedc3b512b4b7 Mon Sep 17 00:00:00 2001 From: Xiang Chen Date: Mon, 5 Aug 2019 21:48:04 +0800 Subject: [PATCH] scsi: hisi_sas: Don't bother clearing status buffer IU in task prep For struct hisi_sas_status_buffer, it contains struct hisi_sas_err_record and iu[1024]. The struct iu[1024] will be filled fully by the response of disks, so it is not need to initialize them to 0, but for the struct hisi_sas_err_record, SAS controller only fill some fields of hisi_sas_err_record according to hw designer, so it should be initialised to 0. After the change, cpu utilization percentage of memset() is changed from 1.7% to 0.12%. Signed-off-by: Xiang Chen Signed-off-by: John Garry Signed-off-by: Martin K. Petersen --- drivers/scsi/hisi_sas/hisi_sas_main.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c index 02ad91c01a44..7efa8dfa0cc1 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_main.c +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c @@ -545,7 +545,8 @@ static int hisi_sas_task_prep(struct sas_task *task, memset(slot->cmd_hdr, 0, sizeof(struct hisi_sas_cmd_hdr)); memset(hisi_sas_cmd_hdr_addr_mem(slot), 0, HISI_SAS_COMMAND_TABLE_SZ); - memset(hisi_sas_status_buf_addr_mem(slot), 0, HISI_SAS_STATUS_BUF_SZ); + memset(hisi_sas_status_buf_addr_mem(slot), 0, + sizeof(struct hisi_sas_err_record)); switch (task->task_proto) { case SAS_PROTOCOL_SMP: @@ -2005,7 +2006,8 @@ hisi_sas_internal_abort_task_exec(struct hisi_hba *hisi_hba, int device_id, memset(slot->cmd_hdr, 0, sizeof(struct hisi_sas_cmd_hdr)); memset(hisi_sas_cmd_hdr_addr_mem(slot), 0, HISI_SAS_COMMAND_TABLE_SZ); - memset(hisi_sas_status_buf_addr_mem(slot), 0, HISI_SAS_STATUS_BUF_SZ); + memset(hisi_sas_status_buf_addr_mem(slot), 0, + sizeof(struct hisi_sas_err_record)); hisi_sas_task_prep_abort(hisi_hba, slot, device_id, abort_flag, task_tag);