sfc: Fill RX rings completely full, rather than to 95% full

There was no runtime control of the fast_fill_limit in any case, so purged
that field.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index f0385e1..eaca447 100644 (file)
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -252,8 +252,6 @@ struct efx_rx_page_state {
  * @max_fill: RX descriptor maximum fill level (<= ring size)
  * @fast_fill_trigger: RX descriptor fill level that will trigger a fast fill
  *     (<= @max_fill)
- * @fast_fill_limit: The level to which a fast fill will fill
- *     (@fast_fill_trigger <= @fast_fill_limit <= @max_fill)
  * @min_fill: RX descriptor minimum non-zero fill level.
  *     This records the minimum fill level observed when a ring
  *     refill was triggered.
@@ -274,7 +272,6 @@ struct efx_rx_queue {
        int removed_count;
        unsigned int max_fill;
        unsigned int fast_fill_trigger;
-       unsigned int fast_fill_limit;
        unsigned int min_fill;
        unsigned int min_overfill;
        unsigned int alloc_page_count;

diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
index 763fa2f..254fec8 100644 (file)
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -78,11 +78,6 @@ static int rx_alloc_method = RX_ALLOC_METHOD_AUTO;
  */
 static unsigned int rx_refill_threshold = 90;
 
-/* This is the percentage fill level to which an RX queue will be refilled
- * when the "RX refill threshold" is reached.
- */
-static unsigned int rx_refill_limit = 95;
-
 /*
  * RX maximum head room required.
  *
@@ -342,7 +337,7 @@ static void efx_recycle_rx_buffer(struct efx_channel *channel,
  * efx_fast_push_rx_descriptors - push new RX descriptors quickly
  * @rx_queue:          RX descriptor queue
  * This will aim to fill the RX descriptor queue up to
- * @rx_queue->@fast_fill_limit. If there is insufficient atomic
+ * @rx_queue->@max_fill. If there is insufficient atomic
  * memory to do so, a slow fill will be scheduled.
  *
  * The caller must provide serialisation (none is used here). In practise,
@@ -367,7 +362,7 @@ void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue)
                        rx_queue->min_fill = fill_level;
        }
 
-       space = rx_queue->fast_fill_limit - fill_level;
+       space = rx_queue->max_fill - fill_level;
        if (space < EFX_RX_BATCH)
                goto out;
 
@@ -375,7 +370,7 @@ void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue)
                   "RX queue %d fast-filling descriptor ring from"
                   " level %d to level %d using %s allocation\n",
                   efx_rx_queue_index(rx_queue), fill_level,
-                  rx_queue->fast_fill_limit,
+                  rx_queue->max_fill,
                   channel->rx_alloc_push_pages ? "page" : "skb");
 
        do {
@@ -681,7 +676,7 @@ int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
 void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
 {
        struct efx_nic *efx = rx_queue->efx;
-       unsigned int max_fill, trigger, limit;
+       unsigned int max_fill, trigger;
 
        netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
                  "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
@@ -695,11 +690,9 @@ void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
        /* Initialise limit fields */
        max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
        trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
-       limit = max_fill * min(rx_refill_limit, 100U) / 100U;
 
        rx_queue->max_fill = max_fill;
        rx_queue->fast_fill_trigger = trigger;
-       rx_queue->fast_fill_limit = limit;
 
        /* Set up RX descriptor ring */
        rx_queue->enabled = true;