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Diffstat (limited to 'net/core/dev.c')
-rw-r--r--net/core/dev.c89
1 files changed, 68 insertions, 21 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index e3f998d5c15c..ce8fea2e2788 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6448,7 +6448,8 @@ bool napi_complete_done(struct napi_struct *n, int work_done)
WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
- new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED);
+ new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
+ NAPIF_STATE_PREFER_BUSY_POLL);
/* If STATE_MISSED was set, leave STATE_SCHED set,
* because we will call napi->poll() one more time.
@@ -6485,10 +6486,30 @@ static struct napi_struct *napi_by_id(unsigned int napi_id)
#if defined(CONFIG_NET_RX_BUSY_POLL)
-#define BUSY_POLL_BUDGET 8
+static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
+{
+ if (!skip_schedule) {
+ gro_normal_list(napi);
+ __napi_schedule(napi);
+ return;
+ }
+
+ if (napi->gro_bitmask) {
+ /* flush too old packets
+ * If HZ < 1000, flush all packets.
+ */
+ napi_gro_flush(napi, HZ >= 1000);
+ }
-static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock)
+ gro_normal_list(napi);
+ clear_bit(NAPI_STATE_SCHED, &napi->state);
+}
+
+static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
+ u16 budget)
{
+ bool skip_schedule = false;
+ unsigned long timeout;
int rc;
/* Busy polling means there is a high chance device driver hard irq
@@ -6505,29 +6526,33 @@ static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock)
local_bh_disable();
+ if (prefer_busy_poll) {
+ napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
+ timeout = READ_ONCE(napi->dev->gro_flush_timeout);
+ if (napi->defer_hard_irqs_count && timeout) {
+ hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
+ skip_schedule = true;
+ }
+ }
+
/* All we really want here is to re-enable device interrupts.
* Ideally, a new ndo_busy_poll_stop() could avoid another round.
*/
- rc = napi->poll(napi, BUSY_POLL_BUDGET);
+ rc = napi->poll(napi, budget);
/* We can't gro_normal_list() here, because napi->poll() might have
* rearmed the napi (napi_complete_done()) in which case it could
* already be running on another CPU.
*/
- trace_napi_poll(napi, rc, BUSY_POLL_BUDGET);
+ trace_napi_poll(napi, rc, budget);
netpoll_poll_unlock(have_poll_lock);
- if (rc == BUSY_POLL_BUDGET) {
- /* As the whole budget was spent, we still own the napi so can
- * safely handle the rx_list.
- */
- gro_normal_list(napi);
- __napi_schedule(napi);
- }
+ if (rc == budget)
+ __busy_poll_stop(napi, skip_schedule);
local_bh_enable();
}
void napi_busy_loop(unsigned int napi_id,
bool (*loop_end)(void *, unsigned long),
- void *loop_end_arg)
+ void *loop_end_arg, bool prefer_busy_poll, u16 budget)
{
unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
int (*napi_poll)(struct napi_struct *napi, int budget);
@@ -6555,17 +6580,23 @@ restart:
* we avoid dirtying napi->state as much as we can.
*/
if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
- NAPIF_STATE_IN_BUSY_POLL))
+ NAPIF_STATE_IN_BUSY_POLL)) {
+ if (prefer_busy_poll)
+ set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
goto count;
+ }
if (cmpxchg(&napi->state, val,
val | NAPIF_STATE_IN_BUSY_POLL |
- NAPIF_STATE_SCHED) != val)
+ NAPIF_STATE_SCHED) != val) {
+ if (prefer_busy_poll)
+ set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
goto count;
+ }
have_poll_lock = netpoll_poll_lock(napi);
napi_poll = napi->poll;
}
- work = napi_poll(napi, BUSY_POLL_BUDGET);
- trace_napi_poll(napi, work, BUSY_POLL_BUDGET);
+ work = napi_poll(napi, budget);
+ trace_napi_poll(napi, work, budget);
gro_normal_list(napi);
count:
if (work > 0)
@@ -6578,7 +6609,7 @@ count:
if (unlikely(need_resched())) {
if (napi_poll)
- busy_poll_stop(napi, have_poll_lock);
+ busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
preempt_enable();
rcu_read_unlock();
cond_resched();
@@ -6589,7 +6620,7 @@ count:
cpu_relax();
}
if (napi_poll)
- busy_poll_stop(napi, have_poll_lock);
+ busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
preempt_enable();
out:
rcu_read_unlock();
@@ -6640,8 +6671,10 @@ static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
* NAPI_STATE_MISSED, since we do not react to a device IRQ.
*/
if (!napi_disable_pending(napi) &&
- !test_and_set_bit(NAPI_STATE_SCHED, &napi->state))
+ !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
+ clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
__napi_schedule_irqoff(napi);
+ }
return HRTIMER_NORESTART;
}
@@ -6699,6 +6732,7 @@ void napi_disable(struct napi_struct *n)
hrtimer_cancel(&n->timer);
+ clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &n->state);
clear_bit(NAPI_STATE_DISABLE, &n->state);
}
EXPORT_SYMBOL(napi_disable);
@@ -6771,6 +6805,19 @@ static int napi_poll(struct napi_struct *n, struct list_head *repoll)
goto out_unlock;
}
+ /* The NAPI context has more processing work, but busy-polling
+ * is preferred. Exit early.
+ */
+ if (napi_prefer_busy_poll(n)) {
+ if (napi_complete_done(n, work)) {
+ /* If timeout is not set, we need to make sure
+ * that the NAPI is re-scheduled.
+ */
+ napi_schedule(n);
+ }
+ goto out_unlock;
+ }
+
if (n->gro_bitmask) {
/* flush too old packets
* If HZ < 1000, flush all packets.
@@ -9753,7 +9800,7 @@ static int netif_alloc_rx_queues(struct net_device *dev)
rx[i].dev = dev;
/* XDP RX-queue setup */
- err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i);
+ err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
if (err < 0)
goto err_rxq_info;
}