From: Patrick Mansfield <patmans@us.ibm.com>
To: James Bottomley <James.Bottomley@steeleye.com>,
linux-scsi@vger.kernel.org
Subject: [patch] 3/5 scsi-locking-2.5 prevent looping when processing starved queues
Date: Wed, 9 Apr 2003 16:47:33 -0700 [thread overview]
Message-ID: <20030409164733.C23701@beaverton.ibm.com> (raw)
In-Reply-To: <20030409164701.B23701@beaverton.ibm.com>; from patmans@us.ibm.com on Wed, Apr 09, 2003 at 04:47:01PM -0700
Ensure that we cannot loop forever (however unlikely) when processing the
starved queues.
diff -purN -X /home/patman/dontdiff 02_no_hier/drivers/scsi/scsi_lib.c 03_no_loop/drivers/scsi/scsi_lib.c
--- 02_no_hier/drivers/scsi/scsi_lib.c Wed Apr 9 12:39:20 2003
+++ 03_no_loop/drivers/scsi/scsi_lib.c Wed Apr 9 12:39:22 2003
@@ -470,6 +470,13 @@ void scsi_queue_next_request(request_que
spin_unlock_irqrestore(sdev2->request_queue->queue_lock, flags);
spin_lock_irqsave(shost->host_lock, flags);
+ if (unlikely(!list_empty(&sdev->starved_entry)))
+ /*
+ * sdev lost a race, and was put back on the
+ * starved list. This is unlikely but without this
+ * in theory we could loop forever.
+ */
+ break;
}
spin_unlock_irqrestore(shost->host_lock, flags);
next prev parent reply other threads:[~2003-04-09 23:39 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-04-09 23:46 [patch] 1/5 scsi-locking-2.5 single_lun store scsi_device pointer Patrick Mansfield
2003-04-09 23:47 ` [patch] 2/5 scsi-locking-2.5 remove lock hierarchy Patrick Mansfield
2003-04-09 23:47 ` Patrick Mansfield [this message]
2003-04-09 23:47 ` [patch] 4/5 scsi-locking-2.5 list_del starved_entry plus use GFP_ATOMIC Patrick Mansfield
2003-04-09 23:48 ` [patch] 5/5 scsi-locking-2.5 remove extra sdev2, remove extra logging Patrick Mansfield
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