Skip to content

Commit

Permalink
cxgb3: separate TX and RX reclaim handlers
Browse files Browse the repository at this point in the history 
Separate TX and RX reclaim handlers
Don't disable interrupts in RX reclaim handler.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
Divy Le Ray authored and David S. Miller committed Mar 13, 2009
1 parent b2b964f commit 42c8ea1
Show file tree
Hide file tree
Showing 2 changed files with 89 additions and 40 deletions.
1 change: 1 addition & 0 deletions drivers/net/cxgb3/adapter.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -197,6 +197,7 @@ struct sge_qset { /* an SGE queue set */
struct netdev_queue *tx_q; /* associated netdev TX queue */
unsigned long txq_stopped; /* which Tx queues are stopped */
struct timer_list tx_reclaim_timer; /* reclaims TX buffers */
struct timer_list rx_reclaim_timer; /* reclaims RX buffers */
unsigned long port_stats[SGE_PSTAT_MAX];
} ____cacheline_aligned;

Expand Down
128 changes: 88 additions & 40 deletions drivers/net/cxgb3/sge.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -61,6 +61,7 @@
#define FL1_PG_ORDER (PAGE_SIZE > 8192 ? 0 : 1)

#define SGE_RX_DROP_THRES 16
#define RX_RECLAIM_PERIOD (HZ/4)

/*
* Max number of Rx buffers we replenish at a time.
Expand All @@ -71,6 +72,8 @@
* frequently as Tx buffers are usually reclaimed by new Tx packets.
*/
#define TX_RECLAIM_PERIOD (HZ / 4)
#define TX_RECLAIM_TIMER_CHUNK 64U
#define TX_RECLAIM_CHUNK 16U

/* WR size in bytes */
#define WR_LEN (WR_FLITS * 8)
Expand Down Expand Up @@ -308,21 +311,25 @@ static void free_tx_desc(struct adapter *adapter, struct sge_txq *q,
* reclaim_completed_tx - reclaims completed Tx descriptors
* @adapter: the adapter
* @q: the Tx queue to reclaim completed descriptors from
* @chunk: maximum number of descriptors to reclaim
*
* Reclaims Tx descriptors that the SGE has indicated it has processed,
* and frees the associated buffers if possible. Called with the Tx
* queue's lock held.
*/
static inline void reclaim_completed_tx(struct adapter *adapter,
struct sge_txq *q)
static inline unsigned int reclaim_completed_tx(struct adapter *adapter,
struct sge_txq *q,
unsigned int chunk)
{
unsigned int reclaim = q->processed - q->cleaned;

reclaim = min(chunk, reclaim);
if (reclaim) {
free_tx_desc(adapter, q, reclaim);
q->cleaned += reclaim;
q->in_use -= reclaim;
}
return q->processed - q->cleaned;
}

/**
Expand Down Expand Up @@ -601,6 +608,7 @@ static void t3_reset_qset(struct sge_qset *q)
memset(q->txq, 0, sizeof(struct sge_txq) * SGE_TXQ_PER_SET);
q->txq_stopped = 0;
q->tx_reclaim_timer.function = NULL; /* for t3_stop_sge_timers() */
q->rx_reclaim_timer.function = NULL;
q->lro_frag_tbl.nr_frags = q->lro_frag_tbl.len = 0;
}

Expand Down Expand Up @@ -1179,7 +1187,7 @@ int t3_eth_xmit(struct sk_buff *skb, struct net_device *dev)
txq = netdev_get_tx_queue(dev, qidx);

spin_lock(&q->lock);
reclaim_completed_tx(adap, q);
reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK);

credits = q->size - q->in_use;
ndesc = calc_tx_descs(skb);
Expand Down Expand Up @@ -1588,7 +1596,7 @@ static int ofld_xmit(struct adapter *adap, struct sge_txq *q,
unsigned int ndesc = calc_tx_descs_ofld(skb), pidx, gen;

spin_lock(&q->lock);
again:reclaim_completed_tx(adap, q);
again: reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK);

ret = check_desc_avail(adap, q, skb, ndesc, TXQ_OFLD);
if (unlikely(ret)) {
Expand Down Expand Up @@ -1630,7 +1638,7 @@ static void restart_offloadq(unsigned long data)
struct adapter *adap = pi->adapter;

spin_lock(&q->lock);
again:reclaim_completed_tx(adap, q);
again: reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK);

while ((skb = skb_peek(&q->sendq)) != NULL) {
unsigned int gen, pidx;
Expand Down Expand Up @@ -2747,13 +2755,13 @@ void t3_sge_err_intr_handler(struct adapter *adapter)
}

/**
* sge_timer_cb - perform periodic maintenance of an SGE qset
* sge_timer_tx - perform periodic maintenance of an SGE qset
* @data: the SGE queue set to maintain
*
* Runs periodically from a timer to perform maintenance of an SGE queue
* set. It performs two tasks:
*
* a) Cleans up any completed Tx descriptors that may still be pending.
* Cleans up any completed Tx descriptors that may still be pending.
* Normal descriptor cleanup happens when new packets are added to a Tx
* queue so this timer is relatively infrequent and does any cleanup only
* if the Tx queue has not seen any new packets in a while. We make a
Expand All @@ -2763,51 +2771,87 @@ void t3_sge_err_intr_handler(struct adapter *adapter)
* up). Since control queues use immediate data exclusively we don't
* bother cleaning them up here.
*
* b) Replenishes Rx queues that have run out due to memory shortage.
* Normally new Rx buffers are added when existing ones are consumed but
* when out of memory a queue can become empty. We try to add only a few
* buffers here, the queue will be replenished fully as these new buffers
* are used up if memory shortage has subsided.
*/
static void sge_timer_cb(unsigned long data)
static void sge_timer_tx(unsigned long data)
{
spinlock_t *lock;
struct sge_qset *qs = (struct sge_qset *)data;
struct adapter *adap = qs->adap;
struct port_info *pi = netdev_priv(qs->netdev);
struct adapter *adap = pi->adapter;
unsigned int tbd[SGE_TXQ_PER_SET] = {0, 0};
unsigned long next_period;

if (spin_trylock(&qs->txq[TXQ_ETH].lock)) {
reclaim_completed_tx(adap, &qs->txq[TXQ_ETH]);
tbd[TXQ_ETH] = reclaim_completed_tx(adap, &qs->txq[TXQ_ETH],
TX_RECLAIM_TIMER_CHUNK);
spin_unlock(&qs->txq[TXQ_ETH].lock);
}
if (spin_trylock(&qs->txq[TXQ_OFLD].lock)) {
reclaim_completed_tx(adap, &qs->txq[TXQ_OFLD]);
tbd[TXQ_OFLD] = reclaim_completed_tx(adap, &qs->txq[TXQ_OFLD],
TX_RECLAIM_TIMER_CHUNK);
spin_unlock(&qs->txq[TXQ_OFLD].lock);
}
lock = (adap->flags & USING_MSIX) ? &qs->rspq.lock :
&adap->sge.qs[0].rspq.lock;
if (spin_trylock_irq(lock)) {
if (!napi_is_scheduled(&qs->napi)) {
u32 status = t3_read_reg(adap, A_SG_RSPQ_FL_STATUS);

if (qs->fl[0].credits < qs->fl[0].size)
__refill_fl(adap, &qs->fl[0]);
if (qs->fl[1].credits < qs->fl[1].size)
__refill_fl(adap, &qs->fl[1]);

if (status & (1 << qs->rspq.cntxt_id)) {
qs->rspq.starved++;
if (qs->rspq.credits) {
refill_rspq(adap, &qs->rspq, 1);
qs->rspq.credits--;
qs->rspq.restarted++;
t3_write_reg(adap, A_SG_RSPQ_FL_STATUS,
1 << qs->rspq.cntxt_id);
}

next_period = TX_RECLAIM_PERIOD >>
(max(tbd[TXQ_ETH], tbd[TXQ_OFLD]) /
TX_RECLAIM_TIMER_CHUNK);
mod_timer(&qs->tx_reclaim_timer, jiffies + next_period);
}

/*
* sge_timer_rx - perform periodic maintenance of an SGE qset
* @data: the SGE queue set to maintain
*
* a) Replenishes Rx queues that have run out due to memory shortage.
* Normally new Rx buffers are added when existing ones are consumed but
* when out of memory a queue can become empty. We try to add only a few
* buffers here, the queue will be replenished fully as these new buffers
* are used up if memory shortage has subsided.
*
* b) Return coalesced response queue credits in case a response queue is
* starved.
*
*/
static void sge_timer_rx(unsigned long data)
{
spinlock_t *lock;
struct sge_qset *qs = (struct sge_qset *)data;
struct port_info *pi = netdev_priv(qs->netdev);
struct adapter *adap = pi->adapter;
u32 status;

lock = adap->params.rev > 0 ?
&qs->rspq.lock : &adap->sge.qs[0].rspq.lock;

if (!spin_trylock_irq(lock))
goto out;

if (napi_is_scheduled(&qs->napi))
goto unlock;

if (adap->params.rev < 4) {
status = t3_read_reg(adap, A_SG_RSPQ_FL_STATUS);

if (status & (1 << qs->rspq.cntxt_id)) {
qs->rspq.starved++;
if (qs->rspq.credits) {
qs->rspq.credits--;
refill_rspq(adap, &qs->rspq, 1);
qs->rspq.restarted++;
t3_write_reg(adap, A_SG_RSPQ_FL_STATUS,
1 << qs->rspq.cntxt_id);
}
}
spin_unlock_irq(lock);
}
mod_timer(&qs->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);

if (qs->fl[0].credits < qs->fl[0].size)
__refill_fl(adap, &qs->fl[0]);
if (qs->fl[1].credits < qs->fl[1].size)
__refill_fl(adap, &qs->fl[1]);

unlock:
spin_unlock_irq(lock);
out:
mod_timer(&qs->rx_reclaim_timer, jiffies + RX_RECLAIM_PERIOD);
}

/**
Expand Down Expand Up @@ -2850,7 +2894,8 @@ int t3_sge_alloc_qset(struct adapter *adapter, unsigned int id, int nports,
struct sge_qset *q = &adapter->sge.qs[id];

init_qset_cntxt(q, id);
setup_timer(&q->tx_reclaim_timer, sge_timer_cb, (unsigned long)q);
setup_timer(&q->tx_reclaim_timer, sge_timer_tx, (unsigned long)q);
setup_timer(&q->rx_reclaim_timer, sge_timer_rx, (unsigned long)q);

q->fl[0].desc = alloc_ring(adapter->pdev, p->fl_size,
sizeof(struct rx_desc),
Expand Down Expand Up @@ -2999,6 +3044,7 @@ int t3_sge_alloc_qset(struct adapter *adapter, unsigned int id, int nports,
V_NEWTIMER(q->rspq.holdoff_tmr));

mod_timer(&q->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
mod_timer(&q->rx_reclaim_timer, jiffies + RX_RECLAIM_PERIOD);

return 0;

Expand All @@ -3024,6 +3070,8 @@ void t3_stop_sge_timers(struct adapter *adap)

if (q->tx_reclaim_timer.function)
del_timer_sync(&q->tx_reclaim_timer);
if (q->rx_reclaim_timer.function)
del_timer_sync(&q->rx_reclaim_timer);
}
}

Expand Down

0 comments on commit 42c8ea1

Please sign in to comment.