diff options
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ethernet/freescale/dpa/dpaa_eth.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/drivers/net/ethernet/freescale/dpa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpa/dpaa_eth.c index 2106553..9294c80 100644 --- a/drivers/net/ethernet/freescale/dpa/dpaa_eth.c +++ b/drivers/net/ethernet/freescale/dpa/dpaa_eth.c @@ -130,13 +130,17 @@ #define DPA_MAX_FD_OFFSET ((1 << 9) - 1) /* - * Extra size of a buffer (beyond the size of the buffers that are seeded into - * the global pool) for which recycling is allowed. - * The value is arbitrary, but tries to reach a balance such that originating - * frames may get recycled, while forwarded skbs that get reallocated on Tx - * aren't allowed to grow unboundedly. + * Maximum size of a buffer for which recycling is allowed. + * We need an upper limit such that forwarded skbs that get reallocated on Tx + * aren't allowed to grow unboundedly. On the other hand, we need to make sure + * that skbs allocated by us will not fail to be recycled due to their size. + * + * For a requested size, the kernel allocator provides the next power of two + * sized block, which the stack will use as is, regardless of the actual size + * it required; since we must acommodate at most 9.6K buffers (L2 maximum + * supported frame size), set the recycling upper limit to 16K. */ -#define DPA_RECYCLE_EXTRA_SIZE 1024 +#define DPA_RECYCLE_MAX_SIZE 16384 /* For MAC-based interfaces, we compute the tx needed headroom from the * associated Tx port's buffer layout settings. @@ -1944,8 +1948,7 @@ static int skb_to_contig_fd(struct dpa_priv_s *priv, * - there's enough room in the buffer pool */ if (likely(skb_is_recycleable(skb, dpa_bp->size) && - (skb_end_pointer(skb) - skb->head <= - dpa_bp->size + DPA_RECYCLE_EXTRA_SIZE) && + (skb_end_pointer(skb) - skb->head <= DPA_RECYCLE_MAX_SIZE) && (*percpu_priv->dpa_bp_count < dpa_bp->target_count))) { /* Compute the minimum necessary fd offset */ offset = dpa_bp->size - skb->len - skb_tailroom(skb); |