cxgb3: ring rx door bell less frequently (26b3871d) · Commits · 戴 / test

drivers/net/cxgb3/adapter.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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 */

drivers/net/cxgb3/sge.c

+24 −8

Original line number	Diff line number	Diff line
		@@ -62,6 +62,10 @@

		#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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