]> err.no Git - linux-2.6/commitdiff
[SCSI] advansys: Remove `waiting' queue
authorMatthew Wilcox <matthew@wil.cx>
Sun, 9 Sep 2007 14:56:31 +0000 (08:56 -0600)
committerJames Bottomley <jejb@mulgrave.localdomain>
Fri, 12 Oct 2007 18:47:44 +0000 (14:47 -0400)
If the adapter is busy, return the request to the midlayer rather than
queueing it in the driver.  asc_execute_queue() and asc_dequeue() become
unused, and we don't need to print out stats on the waiting queue any more.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
drivers/scsi/advansys.c

index fe289b1d7ddbfd30772a39fc33846b01709cec93..526239a21332039b2c9703a146f7e1275df44f77 100644 (file)
@@ -2852,7 +2852,6 @@ typedef struct asc_board {
        } dvc_cfg;
        ushort asc_n_io_port;   /* Number I/O ports. */
        asc_queue_t active;     /* Active command queue */
-       asc_queue_t waiting;    /* Waiting command queue */
        asc_queue_t done;       /* Done command queue */
        ADV_SCSI_BIT_ID_TYPE init_tidmask;      /* Target init./valid mask */
        struct scsi_device *device[ADV_MAX_TID + 1];    /* Mid-Level Scsi Device */
@@ -2922,10 +2921,8 @@ static int asc_build_req(asc_board_t *, struct scsi_cmnd *);
 static int adv_build_req(asc_board_t *, struct scsi_cmnd *, ADV_SCSI_REQ_Q **);
 static int adv_get_sglist(asc_board_t *, adv_req_t *, struct scsi_cmnd *, int);
 static void asc_enqueue(asc_queue_t *, REQP, int);
-static REQP asc_dequeue(asc_queue_t *, int);
 static REQP asc_dequeue_list(asc_queue_t *, REQP *, int);
 static int asc_rmqueue(asc_queue_t *, REQP);
-static void asc_execute_queue(asc_queue_t *);
 #ifdef CONFIG_PROC_FS
 static int asc_proc_copy(off_t, off_t, char *, int, char *, int);
 static int asc_prt_board_devices(struct Scsi_Host *, char *, int);
@@ -3274,6 +3271,7 @@ advansys_queuecommand(struct scsi_cmnd *scp, void (*done) (struct scsi_cmnd *))
        asc_board_t *boardp;
        ulong flags;
        struct scsi_cmnd *done_scp;
+       int asc_res, result = 0;
 
        shost = scp->device->host;
        boardp = ASC_BOARDP(shost);
@@ -3302,37 +3300,13 @@ advansys_queuecommand(struct scsi_cmnd *scp, void (*done) (struct scsi_cmnd *))
                return 0;
        }
 
-       /*
-        * Attempt to execute any waiting commands for the board.
-        */
-       if (!ASC_QUEUE_EMPTY(&boardp->waiting)) {
-               ASC_DBG(1,
-                       "advansys_queuecommand: before asc_execute_queue() waiting\n");
-               asc_execute_queue(&boardp->waiting);
-       }
-
-       /*
-        * Save the function pointer to Linux mid-level 'done' function
-        * and attempt to execute the command.
-        *
-        * If ASC_NOERROR is returned the request has been added to the
-        * board's 'active' queue and will be completed by the interrupt
-        * handler.
-        *
-        * If ASC_BUSY is returned add the request to the board's per
-        * target waiting list. This is the first time the request has
-        * been tried. Add it to the back of the waiting list. It will be
-        * retried later.
-        *
-        * If an error occurred, the request will have been placed on the
-        * board's 'done' queue and must be completed before returning.
-        */
        scp->scsi_done = done;
-       switch (asc_execute_scsi_cmnd(scp)) {
+       asc_res = asc_execute_scsi_cmnd(scp);
+       switch (asc_res) {
        case ASC_NOERROR:
                break;
        case ASC_BUSY:
-               asc_enqueue(&boardp->waiting, scp, ASC_BACK);
+               result = SCSI_MLQUEUE_HOST_BUSY;
                break;
        case ASC_ERROR:
        default:
@@ -3343,7 +3317,7 @@ advansys_queuecommand(struct scsi_cmnd *scp, void (*done) (struct scsi_cmnd *))
        }
        spin_unlock_irqrestore(&boardp->lock, flags);
 
-       return 0;
+       return result;
 }
 
 /*
@@ -3488,33 +3462,6 @@ static int advansys_reset(struct scsi_cmnd *scp)
                }
        }
 
-       /*
-        * Dequeue all 'waiting' requests and set the request status
-        * to DID_RESET.
-        */
-       if (done_scp == NULL) {
-               done_scp = asc_dequeue_list(&boardp->waiting, &last_scp,
-                                           ASC_TID_ALL);
-               for (tscp = done_scp; tscp; tscp = REQPNEXT(tscp)) {
-                       tscp->result = HOST_BYTE(DID_RESET);
-               }
-       } else {
-               /* Append to 'done_scp' at the end with 'last_scp'. */
-               ASC_ASSERT(last_scp != NULL);
-               last_scp->host_scribble =
-                   (unsigned char *)asc_dequeue_list(&boardp->waiting,
-                                                     &new_last_scp,
-                                                     ASC_TID_ALL);
-               if (new_last_scp != NULL) {
-                       ASC_ASSERT(REQPNEXT(last_scp) != NULL);
-                       for (tscp = REQPNEXT(last_scp); tscp;
-                            tscp = REQPNEXT(tscp)) {
-                               tscp->result = HOST_BYTE(DID_RESET);
-                       }
-                       last_scp = new_last_scp;
-               }
-       }
-
        /* Save the time of the most recently completed reset. */
        boardp->last_reset = jiffies;
 
@@ -3650,7 +3597,7 @@ static irqreturn_t advansys_interrupt(int irq, void *dev_id)
        }
 
        /*
-        * Start waiting requests and create a list of completed requests.
+        * Create a list of completed requests.
         *
         * If a reset request is being performed for the board, the reset
         * handler will complete pending requests after it has completed.
@@ -3659,13 +3606,6 @@ static irqreturn_t advansys_interrupt(int irq, void *dev_id)
                ASC_DBG2(1, "advansys_interrupt: done_scp 0x%p, "
                         "last_scp 0x%p\n", done_scp, last_scp);
 
-               /* Start any waiting commands for the board. */
-               if (!ASC_QUEUE_EMPTY(&boardp->waiting)) {
-                       ASC_DBG(1, "advansys_interrupt: before "
-                               "asc_execute_queue()\n");
-                       asc_execute_queue(&boardp->waiting);
-               }
-
                /*
                 * Add to the list of requests that must be completed.
                 *
@@ -3986,8 +3926,8 @@ static void asc_scsi_done_list(struct scsi_cmnd *scp)
  * If this function returns ASC_NOERROR the request has been enqueued
  * on the board's 'done' queue and must be completed by the caller.
  *
- * If ASC_BUSY is returned the request will be enqueued by the
- * caller on the target's waiting queue and re-tried later.
+ * If ASC_BUSY is returned the request will be returned to the midlayer
+ * and re-tried later.
  */
 static int asc_execute_scsi_cmnd(struct scsi_cmnd *scp)
 {
@@ -4043,10 +3983,6 @@ static int asc_execute_scsi_cmnd(struct scsi_cmnd *scp)
                                "ASC_NOERROR\n");
                        break;
                case ASC_BUSY:
-                       /*
-                        * Caller will enqueue request on the target's waiting
-                        * queue and retry later.
-                        */
                        ASC_STATS(scp->device->host, exe_busy);
                        break;
                case ASC_ERROR:
@@ -4087,10 +4023,6 @@ static int asc_execute_scsi_cmnd(struct scsi_cmnd *scp)
                        ASC_DBG(1, "asc_execute_scsi_cmnd: adv_build_req "
                                "ASC_BUSY\n");
                        /*
-                        * If busy is returned the request has not been
-                        * enqueued.  It will be enqueued by the caller on the
-                        * target's waiting queue and retried later.
-                        *
                         * The asc_stats fields 'adv_build_noreq' and
                         * 'adv_build_nosg' count wide board busy conditions.
                         * They are updated in adv_build_req and
@@ -4127,10 +4059,6 @@ static int asc_execute_scsi_cmnd(struct scsi_cmnd *scp)
                                "ASC_NOERROR\n");
                        break;
                case ASC_BUSY:
-                       /*
-                        * Caller will enqueue request on the target's waiting
-                        * queue and retry later.
-                        */
                        ASC_STATS(scp->device->host, exe_busy);
                        break;
                case ASC_ERROR:
@@ -5004,39 +4932,6 @@ static void asc_enqueue(asc_queue_t *ascq, REQP reqp, int flag)
        return;
 }
 
-/*
- * Return first queued 'REQP' on the specified queue for
- * the specified target device. Clear the 'tidmask' bit for
- * the device if no more commands are left queued for it.
- *
- * 'REQPNEXT(reqp)' returns reqp's next pointer.
- */
-static REQP asc_dequeue(asc_queue_t *ascq, int tid)
-{
-       REQP reqp;
-
-       ASC_DBG2(3, "asc_dequeue: ascq 0x%lx, tid %d\n", (ulong)ascq, tid);
-       ASC_ASSERT(tid >= 0 && tid <= ADV_MAX_TID);
-       if ((reqp = ascq->q_first[tid]) != NULL) {
-               ASC_ASSERT(ascq->q_tidmask & ADV_TID_TO_TIDMASK(tid));
-               ascq->q_first[tid] = REQPNEXT(reqp);
-               /* If the queue is empty, clear its bit and the last pointer. */
-               if (ascq->q_first[tid] == NULL) {
-                       ascq->q_tidmask &= ~ADV_TID_TO_TIDMASK(tid);
-                       ASC_ASSERT(ascq->q_last[tid] == reqp);
-                       ascq->q_last[tid] = NULL;
-               }
-#ifdef ADVANSYS_STATS
-               /* Maintain request queue statistics. */
-               ascq->q_cur_cnt[tid]--;
-               ASC_ASSERT(ascq->q_cur_cnt[tid] >= 0);
-               REQTIMESTAT("asc_dequeue", ascq, reqp, tid);
-#endif /* ADVANSYS_STATS */
-       }
-       ASC_DBG1(3, "asc_dequeue: reqp 0x%lx\n", (ulong)reqp);
-       return reqp;
-}
-
 /*
  * Return a pointer to a singly linked list of all the requests queued
  * for 'tid' on the 'asc_queue_t' pointed to by 'ascq'.
@@ -5202,45 +5097,6 @@ static int asc_rmqueue(asc_queue_t *ascq, REQP reqp)
        return ret;
 }
 
-/*
- * Execute as many queued requests as possible for the specified queue.
- *
- * Calls asc_execute_scsi_cmnd() to execute a REQP/struct scsi_cmnd.
- */
-static void asc_execute_queue(asc_queue_t *ascq)
-{
-       ADV_SCSI_BIT_ID_TYPE scan_tidmask;
-       REQP reqp;
-       int i;
-
-       ASC_DBG1(1, "asc_execute_queue: ascq 0x%lx\n", (ulong)ascq);
-       /*
-        * Execute queued commands for devices attached to
-        * the current board in round-robin fashion.
-        */
-       scan_tidmask = ascq->q_tidmask;
-       do {
-               for (i = 0; i <= ADV_MAX_TID; i++) {
-                       if (scan_tidmask & ADV_TID_TO_TIDMASK(i)) {
-                               if ((reqp = asc_dequeue(ascq, i)) == NULL) {
-                                       scan_tidmask &= ~ADV_TID_TO_TIDMASK(i);
-                               } else
-                                   if (asc_execute_scsi_cmnd
-                                       ((struct scsi_cmnd *)reqp)
-                                       == ASC_BUSY) {
-                                       scan_tidmask &= ~ADV_TID_TO_TIDMASK(i);
-                                       /*
-                                        * The request returned ASC_BUSY. Enqueue at the front of
-                                        * target's waiting list to maintain correct ordering.
-                                        */
-                                       asc_enqueue(ascq, reqp, ASC_FRONT);
-                               }
-                       }
-               }
-       } while (scan_tidmask);
-       return;
-}
-
 #ifdef CONFIG_PROC_FS
 /*
  * asc_prt_board_devices()
@@ -6723,7 +6579,6 @@ asc_prt_target_stats(struct Scsi_Host *shost, int tgt_id, char *cp, int cplen)
        ushort chip_scsi_id;
        asc_board_t *boardp;
        asc_queue_t *active;
-       asc_queue_t *waiting;
 
        leftlen = cplen;
        totlen = len = 0;
@@ -6732,7 +6587,6 @@ asc_prt_target_stats(struct Scsi_Host *shost, int tgt_id, char *cp, int cplen)
        s = &boardp->asc_stats;
 
        active = &ASC_BOARDP(shost)->active;
-       waiting = &ASC_BOARDP(shost)->waiting;
 
        if (ASC_NARROW_BOARD(boardp)) {
                chip_scsi_id = boardp->dvc_cfg.asc_dvc_cfg.chip_scsi_id;
@@ -6746,8 +6600,7 @@ asc_prt_target_stats(struct Scsi_Host *shost, int tgt_id, char *cp, int cplen)
        }
 
        do {
-               if (active->q_tot_cnt[tgt_id] > 0
-                   || waiting->q_tot_cnt[tgt_id] > 0) {
+               if (active->q_tot_cnt[tgt_id] > 0) {
                        len = asc_prt_line(cp, leftlen, " target %d\n", tgt_id);
                        ASC_PRT_NEXT();
 
@@ -6771,27 +6624,6 @@ asc_prt_target_stats(struct Scsi_Host *shost, int tgt_id, char *cp, int cplen)
                                                                q_tot_cnt
                                                                [tgt_id]));
                        ASC_PRT_NEXT();
-
-                       len = asc_prt_line(cp, leftlen,
-                                          "   waiting: cnt [cur %d, max %d, tot %u], time [min %u, max %u, avg %lu.%01lu]\n",
-                                          waiting->q_cur_cnt[tgt_id],
-                                          waiting->q_max_cnt[tgt_id],
-                                          waiting->q_tot_cnt[tgt_id],
-                                          waiting->q_min_tim[tgt_id],
-                                          waiting->q_max_tim[tgt_id],
-                                          (waiting->q_tot_cnt[tgt_id] ==
-                                           0) ? 0 : (waiting->
-                                                     q_tot_tim[tgt_id] /
-                                                     waiting->
-                                                     q_tot_cnt[tgt_id]),
-                                          (waiting->q_tot_cnt[tgt_id] ==
-                                           0) ? 0 : ASC_TENTHS(waiting->
-                                                               q_tot_tim
-                                                               [tgt_id],
-                                                               waiting->
-                                                               q_tot_cnt
-                                                               [tgt_id]));
-                       ASC_PRT_NEXT();
                }
        } while (0);