Re: [BUG] 3.19-rc1 net: less interrupt masking in NAPI

From: Eric Dumazet
Date: Sat Jan 10 2015 - 16:50:22 EST


On Sat, 2015-01-10 at 23:30 +0200, Oded Gabbay wrote:

> Yes, no problem.
> I will update on the result.

Please try this more complete patch, solving the TX pressure problem as
well, and not lying about NAPI budget. thanks !


diff --git a/drivers/net/ethernet/atheros/alx/main.c b/drivers/net/ethernet/atheros/alx/main.c
index e398eda07298..5f05b387c0a7 100644
--- a/drivers/net/ethernet/atheros/alx/main.c
+++ b/drivers/net/ethernet/atheros/alx/main.c
@@ -184,15 +184,16 @@ static void alx_schedule_reset(struct alx_priv *alx)
schedule_work(&alx->reset_wk);
}

-static bool alx_clean_rx_irq(struct alx_priv *alx, int budget)
+static int alx_clean_rx_irq(struct alx_priv *alx, int budget)
{
struct alx_rx_queue *rxq = &alx->rxq;
struct alx_rrd *rrd;
struct alx_buffer *rxb;
struct sk_buff *skb;
u16 length, rfd_cleaned = 0;
+ int work = 0;

- while (budget > 0) {
+ while (work < budget) {
rrd = &rxq->rrd[rxq->rrd_read_idx];
if (!(rrd->word3 & cpu_to_le32(1 << RRD_UPDATED_SHIFT)))
break;
@@ -243,7 +244,7 @@ static bool alx_clean_rx_irq(struct alx_priv *alx, int budget)
}

napi_gro_receive(&alx->napi, skb);
- budget--;
+ work++;

next_pkt:
if (++rxq->read_idx == alx->rx_ringsz)
@@ -258,21 +259,22 @@ next_pkt:
if (rfd_cleaned)
alx_refill_rx_ring(alx, GFP_ATOMIC);

- return budget > 0;
+ return work;
}

static int alx_poll(struct napi_struct *napi, int budget)
{
struct alx_priv *alx = container_of(napi, struct alx_priv, napi);
struct alx_hw *hw = &alx->hw;
- bool complete = true;
unsigned long flags;
+ bool tx_complete;
+ int work;

- complete = alx_clean_tx_irq(alx) &&
- alx_clean_rx_irq(alx, budget);
+ tx_complete = alx_clean_tx_irq(alx);
+ work = alx_clean_rx_irq(alx, budget);

- if (!complete)
- return 1;
+ if (!tx_complete || work == budget)
+ return budget;

napi_complete(&alx->napi);

@@ -284,7 +286,7 @@ static int alx_poll(struct napi_struct *napi, int budget)

alx_post_write(hw);

- return 0;
+ return work;
}

static irqreturn_t alx_intr_handle(struct alx_priv *alx, u32 intr)


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/