scsi: hisi_sas: Don't bother clearing status buffer IU in task prep (d380f555) · Commits · 戴 / test

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 <chenxiang66@hisilicon.com> Signed-off-by:

John Garry <john.garry@huawei.com> Signed-off-by:

Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/hisi_sas/hisi_sas_main.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -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);

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