From 26b3871d2c82b7c733a3b6d631a6e48c9ebf1c5a Mon Sep 17 00:00:00 2001 From: Divy Le Ray Date: Thu, 12 Mar 2009 21:13:43 +0000 Subject: 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 Signed-off-by: David S. Miller --- drivers/net/cxgb3/adapter.h | 1 + drivers/net/cxgb3/sge.c | 32 ++++++++++++++++++++++++-------- 2 files changed, 25 insertions(+), 8 deletions(-) diff --git a/drivers/net/cxgb3/adapter.h b/drivers/net/cxgb3/adapter.h index fbe15699584e..95dce4832478 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 8205aa4ae945..882beafeb74c 100644 --- a/drivers/net/cxgb3/sge.c +++ b/drivers/net/cxgb3/sge.c @@ -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: -- cgit v1.2.3-59-g8ed1b