2.6.29-stable review patch. If anyone has any objections, please let us know. ------------------ From: Lennert Buytenhek commit 1319ebadf185933e6b7ff95211d3cef9004e9754 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/net/mv643xx_eth.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) --- a/drivers/net/mv643xx_eth.c +++ b/drivers/net/mv643xx_eth.c @@ -372,12 +372,12 @@ 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; @@ -603,7 +603,7 @@ static int rxq_refill(struct rx_queue *r dma_get_cache_alignment() - 1); if (skb == NULL) { - mp->work_rx_oom |= 1 << rxq->index; + mp->oom = 1; goto oom; } @@ -1906,8 +1906,10 @@ static int mv643xx_eth_poll(struct napi_ 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) { @@ -1921,8 +1923,10 @@ static int mv643xx_eth_poll(struct napi_ 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; @@ -1943,7 +1947,7 @@ static int mv643xx_eth_poll(struct napi_ 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(); @@ -1951,7 +1955,7 @@ static int mv643xx_eth_poll(struct napi_ } 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); @@ -2143,7 +2147,7 @@ static int mv643xx_eth_open(struct net_d 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); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/