Thread (13 messages) 13 messages, 5 authors, 2008-10-24

Re: [PATCH 1/2] libata: get rid of ATA_MAX_QUEUE loop in ata_qc_complete_multiple()

From: Tejun Heo <tj@kernel.org>
Date: 2008-10-23 04:14:50
Also in: lkml

Jens Axboe wrote:
quoted hunk ↗ jump to hunk
@@ -4811,16 +4811,19 @@ int ata_qc_complete_multiple(struct ata_port *ap, u32 qc_active)
              return -EINVAL;
      }

-     for (i = 0; i < ATA_MAX_QUEUE; i++) {
+     while (done_mask) {
              struct ata_queued_cmd *qc;
+             unsigned int next = __ffs(done_mask);

-             if (!(done_mask & (1 << i)))
-                     continue;
-
-             if ((qc = ata_qc_from_tag(ap, i))) {
+             qc = ata_qc_from_tag(ap, i + next);
+             if (qc) {
                      ata_qc_complete(qc);
                      nr_done++;
              }
+             if (++next >= ATA_MAX_QUEUE)
+                     break;
+             i += next;
+             done_mask >>= next;
Shouldn't this be...

        i += next + 1;
        if (i >= ATA_MAX_QUEUE)
                break;

or better...

while (done_mask) {
        struct ata_queued_cmd *qc;
        unsigned int next = __ffs(done_mask);

        tag += next;
        if ((qc = ata_qc_from_tag(ap, tag))) {
                ata_qc_complete(qc);
                nr_done++;
        }
        next++;
        tag += next;
        done_mask >>= next;
}

done_mask is guaranteed to be zero at when tag reaches ATA_MAX_QUEUE.

Thanks.

-- 
tejun
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