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scsi: zfcp: drop duplicate seq_no from zfcp_fsf_req which is also in QTCB header

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There is no point for double bookkeeping especially just for tracing.  The
trace can take it from the QTCB which always exists for non-SRB responses
traced with zfcp_dbf_hba_fsf_res().

As a side effect, this removes an alignment hole and reduces the size of
struct zfcp_fsf_req, and thus of each pending request, by 8 bytes.

Before:
$ pahole -C zfcp_fsf_req drivers/s390/scsi/zfcp.ko
...
	struct fsf_qtcb *          qtcb;                 /*   144     8 */
	u32                        seq_no;               /*   152     4 */
	/* XXX 4 bytes hole, try to pack */
	void *                     data;                 /*   160     8 */
...
	/* size: 296, cachelines: 2, members: 14 */
	/* sum members: 288, holes: 2, sum holes: 8 */
	/* last cacheline: 40 bytes */
After:
$ pahole -C zfcp_fsf_req drivers/s390/scsi/zfcp.ko
...
	struct fsf_qtcb *          qtcb;                 /*   144     8 */
	void *                     data;                 /*   152     8 */
...
	/* size: 288, cachelines: 2, members: 13 */
        /* sum members: 284, holes: 1, sum holes: 4 */

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Steffen Maier
2018-11-08 15:44:46 +01:00
committed by Martin K. Petersen
parent f9eca02276
commit 9704154fa0
3 changed files with 1 additions and 4 deletions
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2
drivers/s390/scsi/zfcp_dbf.c
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@@ -82,7 +82,7 @@ void zfcp_dbf_hba_fsf_res(char *tag, int level, struct zfcp_fsf_req *req)
rec->fsf_req_id = req->req_id;
rec->fsf_req_status = req->status;
rec->fsf_cmd = q_head->fsf_command;
rec->fsf_seq_no = req->seq_no;
rec->fsf_seq_no = q_pref->req_seq_no;
rec->u.res.req_issued = req->issued;
rec->u.res.prot_status = q_pref->prot_status;
rec->u.res.fsf_status = q_head->fsf_status;