Revert 927:56df01ffed10

diff --git a/drivers/xen/blkback/blkback.c b/drivers/xen/blkback/blkback.c
index eed6a9e2c78829311d4a19c857c7b29a286e4807..78311e32ceb9bf8f260a1eef130abd70340cc1f1 100644 (file)
--- a/drivers/xen/blkback/blkback.c
+++ b/drivers/xen/blkback/blkback.c
@@ -200,16 +200,6 @@ static void print_stats(blkif_t *blkif)
        blkif->st_oo_req = 0;
 }
 
-static void refill_credit(blkif_t *blkif)
-{
-       blkif->credit_time = jiffies + msecs_to_jiffies(blkif->credit_msec);
-       blkif->available_credit += blkif->credit_req;
-
-       /* this allows for bursting. */
-       if (blkif->available_credit > (blkif->credit_req * blkif->credit_msec))
-               blkif->available_credit = blkif->credit_req;
-}
-
 int blkif_schedule(void *arg)
 {
        blkif_t *blkif = arg;
@@ -237,9 +227,6 @@ int blkif_schedule(void *arg)
                        blkif->waiting_reqs = 1;
                unplug_queue(blkif);
 
-               if (time_after(jiffies, blkif->credit_time))
-                       refill_credit(blkif);
-
                if (log_stats && time_after(jiffies, blkif->st_print))
                        print_stats(blkif);
        }
@@ -326,23 +313,11 @@ static int do_block_io_op(blkif_t *blkif)
        rp = blk_rings->common.sring->req_prod;
        rmb(); /* Ensure we see queued requests up to 'rp'. */
 
-       /* if there's no available request credit right now, and limiting
-        * is requested, then don't bother with going any further.
-        */
-       if (blkif->remaining_credit <= 0 && blkif->credit_req != 0)
-               return (rc != rp) ? 1 : 0;
-
        while (rc != rp) {
 
                if (RING_REQUEST_CONS_OVERFLOW(&blk_rings->common, rc))
                        break;
 
-               /* FIXME: Should we report QoS overages as VBD_OO, or not? */
-               if (blkif->credit_req != 0 && --blkif->remaining_credit <= 0) {
-                       more_to_do = 1;
-                       break;
-               }
-
                if (kthread_should_stop()) {
                        more_to_do = 1;
                        break;

diff --git a/drivers/xen/blkback/common.h b/drivers/xen/blkback/common.h
index c6cd00b4ecf2153f72e0d2a50bd4c4b27544a3b9..6dff5e7612977d708cd9b6a85d42f0d2d522c335 100644 (file)
--- a/drivers/xen/blkback/common.h
+++ b/drivers/xen/blkback/common.h
@@ -96,11 +96,6 @@ typedef struct blkif_st {
 
        grant_handle_t shmem_handle;
        grant_ref_t    shmem_ref;
-
-       int                 credit_req;
-       int                 remaining_credit;
-       int                 credit_msec;
-       unsigned long       credit_time;
 } blkif_t;
 
 blkif_t *blkif_alloc(domid_t domid);

diff --git a/drivers/xen/blkback/xenbus.c b/drivers/xen/blkback/xenbus.c
index f43dfe1ca1abb7c7a073ed41d2d1eb20dcd46ec5..7e689c758117f299dc4969924ac8270168577b2e 100644 (file)
--- a/drivers/xen/blkback/xenbus.c
+++ b/drivers/xen/blkback/xenbus.c
@@ -255,42 +255,6 @@ fail:
        return err;
 }
 
-static void blkback_read_credit(struct xenbus_transaction xbt,
-                               struct xenbus_device *dev,
-                                unsigned long *credit, unsigned long *msec)
-{
-       char *s, *e;
-       unsigned long b, u;
-       char *ratestr;
-
-       /* Default to unlimited I/O operations. */
-       *credit = ~0UL;
-       *usec = 0;
-
-       ratestr = xenbus_read(xbt, dev->nodename, "credit", NULL);
-       if (IS_ERR(ratestr))
-               return;
-
-       s = ratestr;
-       b = simple_strtoul(s, &e, 10);
-       if ((s == e) || (*e != ','))
-               goto fail;
-
-       s = e + 1;
-       u = simple_strtoul(s, &e, 10);
-       if ((s == e) || (*e != '\0'))
-               goto fail;
-
-       *credit = b;
-       *msec = (u / 1000);
-
-       kfree(ratestr);
-       return;
-
- fail:
-       WPRINTK("Failed to parse I/O credit limit. I/O operations are unlimited.\n");
-       kfree(ratestr);
-}
 
 /**
  * Callback received when the hotplug scripts have placed the physical-device
@@ -437,7 +401,6 @@ static void frontend_changed(struct xenbus_device *dev,
 /* ** Connection ** */
 
 
-
 /**
  * Write the physical details regarding the block device to the store, and
  * switch to Connected state.
@@ -462,10 +425,6 @@ again:
        if (err)
                goto abort;
 
-       blkback_read_credit(xbt, dev, &be->blkif->credit_req,
-                           &be->blkif->credit_msec);
-       be->blkif->remaining_credit = be->blkif->credit_req;
-
        err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu",
                            vbd_size(&be->blkif->vbd));
        if (err) {