From 1319ebadf185933e6b7ff95211d3cef9004e9754 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Wed, 29 Apr 2009 11:57:34 +0000 Subject: mv643xx_eth: OOM handling fixes Currently, when OOM occurs during rx ring refill, mv643xx_eth will get into an infinite loop, due to the refill function setting the OOM bit but not clearing the 'rx refill needed' bit for this queue, while the calling function (the NAPI poll handler) will call the refill function in a loop until the 'rx refill needed' bit goes off, without checking the OOM bit. This patch fixes this by checking the OOM bit in the NAPI poll handler before attempting to do rx refill. This means that once OOM occurs, we won't try to do any memory allocations again until the next invocation of the poll handler. While we're at it, change the OOM flag to be a single bit instead of one bit per receive queue since OOM is a system state rather than a per-queue state, and cancel the OOM timer on entry to the NAPI poll handler if it's running to prevent it from firing when we've already come out of OOM. Signed-off-by: Lennert Buytenhek Cc: stable@kernel.org Signed-off-by: David S. Miller --- drivers/net/mv643xx_eth.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c index b3185bf2c158..038beff7da80 100644 --- a/drivers/net/mv643xx_eth.c +++ b/drivers/net/mv643xx_eth.c @@ -393,12 +393,12 @@ struct mv643xx_eth_private { struct work_struct tx_timeout_task; struct napi_struct napi; + u8 oom; u8 work_link; u8 work_tx; u8 work_tx_end; u8 work_rx; u8 work_rx_refill; - u8 work_rx_oom; int skb_size; struct sk_buff_head rx_recycle; @@ -661,7 +661,7 @@ static int rxq_refill(struct rx_queue *rxq, int budget) dma_get_cache_alignment() - 1); if (skb == NULL) { - mp->work_rx_oom |= 1 << rxq->index; + mp->oom = 1; goto oom; } @@ -2167,8 +2167,10 @@ static int mv643xx_eth_poll(struct napi_struct *napi, int budget) mp = container_of(napi, struct mv643xx_eth_private, napi); - mp->work_rx_refill |= mp->work_rx_oom; - mp->work_rx_oom = 0; + if (unlikely(mp->oom)) { + mp->oom = 0; + del_timer(&mp->rx_oom); + } work_done = 0; while (work_done < budget) { @@ -2182,8 +2184,10 @@ static int mv643xx_eth_poll(struct napi_struct *napi, int budget) continue; } - queue_mask = mp->work_tx | mp->work_tx_end | - mp->work_rx | mp->work_rx_refill; + queue_mask = mp->work_tx | mp->work_tx_end | mp->work_rx; + if (likely(!mp->oom)) + queue_mask |= mp->work_rx_refill; + if (!queue_mask) { if (mv643xx_eth_collect_events(mp)) continue; @@ -2204,7 +2208,7 @@ static int mv643xx_eth_poll(struct napi_struct *napi, int budget) txq_maybe_wake(mp->txq + queue); } else if (mp->work_rx & queue_mask) { work_done += rxq_process(mp->rxq + queue, work_tbd); - } else if (mp->work_rx_refill & queue_mask) { + } else if (!mp->oom && (mp->work_rx_refill & queue_mask)) { work_done += rxq_refill(mp->rxq + queue, work_tbd); } else { BUG(); @@ -2212,7 +2216,7 @@ static int mv643xx_eth_poll(struct napi_struct *napi, int budget) } if (work_done < budget) { - if (mp->work_rx_oom) + if (mp->oom) mod_timer(&mp->rx_oom, jiffies + (HZ / 10)); napi_complete(napi); wrlp(mp, INT_MASK, INT_TX_END | INT_RX | INT_EXT); @@ -2372,7 +2376,7 @@ static int mv643xx_eth_open(struct net_device *dev) rxq_refill(mp->rxq + i, INT_MAX); } - if (mp->work_rx_oom) { + if (mp->oom) { mp->rx_oom.expires = jiffies + (HZ / 10); add_timer(&mp->rx_oom); } -- cgit v1.2.2