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authorDivy Le Ray <divy@chelsio.com>2009-03-12 21:13:43 +0000
committerDavid S. Miller <davem@davemloft.net>2009-03-13 11:30:43 -0700
commit26b3871d2c82b7c733a3b6d631a6e48c9ebf1c5a (patch)
tree301a4a1bca9cb85aa8e50bcaa223fa9772afbb90 /drivers
parentff5e2b4732b8386d8354da2cdf7c146487f51736 (diff)
downloadop-kernel-dev-26b3871d2c82b7c733a3b6d631a6e48c9ebf1c5a.zip
op-kernel-dev-26b3871d2c82b7c733a3b6d631a6e48c9ebf1c5a.tar.gz
cxgb3: ring rx door bell less frequently
Ring free lists door bell less frequently, specifically every quarter of the active FL size. Signed-off-by: Divy Le Ray <divy@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/cxgb3/adapter.h1
-rw-r--r--drivers/net/cxgb3/sge.c32
2 files changed, 25 insertions, 8 deletions
diff --git a/drivers/net/cxgb3/adapter.h b/drivers/net/cxgb3/adapter.h
index fbe1569..95dce48 100644
--- a/drivers/net/cxgb3/adapter.h
+++ b/drivers/net/cxgb3/adapter.h
@@ -91,6 +91,7 @@ struct rx_sw_desc;
struct sge_fl { /* SGE per free-buffer list state */
unsigned int buf_size; /* size of each Rx buffer */
unsigned int credits; /* # of available Rx buffers */
+ unsigned int pend_cred; /* new buffers since last FL DB ring */
unsigned int size; /* capacity of free list */
unsigned int cidx; /* consumer index */
unsigned int pidx; /* producer index */
diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c
index 8205aa4..882beaf 100644
--- a/drivers/net/cxgb3/sge.c
+++ b/drivers/net/cxgb3/sge.c
@@ -63,6 +63,10 @@
#define SGE_RX_DROP_THRES 16
/*
+ * Max number of Rx buffers we replenish at a time.
+ */
+#define MAX_RX_REFILL 16U
+/*
* Period of the Tx buffer reclaim timer. This timer does not need to run
* frequently as Tx buffers are usually reclaimed by new Tx packets.
*/
@@ -423,6 +427,14 @@ static int alloc_pg_chunk(struct sge_fl *q, struct rx_sw_desc *sd, gfp_t gfp,
return 0;
}
+static inline void ring_fl_db(struct adapter *adap, struct sge_fl *q)
+{
+ if (q->pend_cred >= q->credits / 4) {
+ q->pend_cred = 0;
+ t3_write_reg(adap, A_SG_KDOORBELL, V_EGRCNTX(q->cntxt_id));
+ }
+}
+
/**
* refill_fl - refill an SGE free-buffer list
* @adapter: the adapter
@@ -478,19 +490,19 @@ nomem: q->alloc_failed++;
sd = q->sdesc;
d = q->desc;
}
- q->credits++;
count++;
}
- wmb();
- if (likely(count))
- t3_write_reg(adap, A_SG_KDOORBELL, V_EGRCNTX(q->cntxt_id));
+
+ q->credits += count;
+ q->pend_cred += count;
+ ring_fl_db(adap, q);
return count;
}
static inline void __refill_fl(struct adapter *adap, struct sge_fl *fl)
{
- refill_fl(adap, fl, min(16U, fl->size - fl->credits),
+ refill_fl(adap, fl, min(MAX_RX_REFILL, fl->size - fl->credits),
GFP_ATOMIC | __GFP_COMP);
}
@@ -515,13 +527,15 @@ static void recycle_rx_buf(struct adapter *adap, struct sge_fl *q,
wmb();
to->len_gen = cpu_to_be32(V_FLD_GEN1(q->gen));
to->gen2 = cpu_to_be32(V_FLD_GEN2(q->gen));
- q->credits++;
if (++q->pidx == q->size) {
q->pidx = 0;
q->gen ^= 1;
}
- t3_write_reg(adap, A_SG_KDOORBELL, V_EGRCNTX(q->cntxt_id));
+
+ q->credits++;
+ q->pend_cred++;
+ ring_fl_db(adap, q);
}
/**
@@ -732,7 +746,9 @@ recycle:
return skb;
}
- if (unlikely(fl->credits < drop_thres))
+ if (unlikely(fl->credits < drop_thres) &&
+ refill_fl(adap, fl, min(MAX_RX_REFILL, fl->size - fl->credits - 1),
+ GFP_ATOMIC | __GFP_COMP) == 0)
goto recycle;
use_orig_buf:
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