diff options
| author | Eric Dumazet <edumazet@google.com> | 2013-06-28 08:05:06 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-04 10:57:36 -0800 |
| commit | 2c4805f3ae216cfd6fc2a386ea523d5a6eee6fdc (patch) | |
| tree | 19f5d5bf88f537a5050506234344ac831085d087 | |
| parent | d4e937777fa1a97b21916eecd7d7d9dd8534d3d1 (diff) | |
iwl3945: better skb management in rx path
commit 45fe142cefa864b685615bcb930159f6749c3667 upstream.
Steinar reported reallocations of skb->head with IPv6, leading to
a warning in skb_try_coalesce()
It turns out iwl3945 has several problems :
1) skb->truesize is underestimated.
We really consume PAGE_SIZE bytes for a fragment,
not the frame length.
2) 128 bytes of initial headroom is a bit low and forces reallocations.
3) We can avoid consuming a full page for small enough frames.
Reported-by: Steinar H. Gunderson <sesse@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Paul Stewart <pstew@google.com>
Acked-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/wireless/iwlegacy/3945.c | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/drivers/net/wireless/iwlegacy/3945.c b/drivers/net/wireless/iwlegacy/3945.c index dc1e6da9976..9a5f36e5c86 100644 --- a/drivers/net/wireless/iwlegacy/3945.c +++ b/drivers/net/wireless/iwlegacy/3945.c @@ -462,6 +462,8 @@ il3945_is_network_packet(struct il_priv *il, struct ieee80211_hdr *header) } } +#define SMALL_PACKET_SIZE 256 + static void il3945_pass_packet_to_mac80211(struct il_priv *il, struct il_rx_buf *rxb, struct ieee80211_rx_status *stats) @@ -470,14 +472,13 @@ il3945_pass_packet_to_mac80211(struct il_priv *il, struct il_rx_buf *rxb, struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)IL_RX_DATA(pkt); struct il3945_rx_frame_hdr *rx_hdr = IL_RX_HDR(pkt); struct il3945_rx_frame_end *rx_end = IL_RX_END(pkt); - u16 len = le16_to_cpu(rx_hdr->len); + u32 len = le16_to_cpu(rx_hdr->len); struct sk_buff *skb; __le16 fc = hdr->frame_control; + u32 fraglen = PAGE_SIZE << il->hw_params.rx_page_order; /* We received data from the HW, so stop the watchdog */ - if (unlikely - (len + IL39_RX_FRAME_SIZE > - PAGE_SIZE << il->hw_params.rx_page_order)) { + if (unlikely(len + IL39_RX_FRAME_SIZE > fraglen)) { D_DROP("Corruption detected!\n"); return; } @@ -488,26 +489,32 @@ il3945_pass_packet_to_mac80211(struct il_priv *il, struct il_rx_buf *rxb, return; } - skb = dev_alloc_skb(128); + skb = dev_alloc_skb(SMALL_PACKET_SIZE); if (!skb) { IL_ERR("dev_alloc_skb failed\n"); return; } if (!il3945_mod_params.sw_crypto) - il_set_decrypted_flag(il, (struct ieee80211_hdr *)rxb_addr(rxb), + il_set_decrypted_flag(il, (struct ieee80211_hdr *)pkt, le32_to_cpu(rx_end->status), stats); - skb_add_rx_frag(skb, 0, rxb->page, - (void *)rx_hdr->payload - (void *)pkt, len, - len); - + /* If frame is small enough to fit into skb->head, copy it + * and do not consume a full page + */ + if (len <= SMALL_PACKET_SIZE) { + memcpy(skb_put(skb, len), rx_hdr->payload, len); + } else { + skb_add_rx_frag(skb, 0, rxb->page, + (void *)rx_hdr->payload - (void *)pkt, len, + fraglen); + il->alloc_rxb_page--; + rxb->page = NULL; + } il_update_stats(il, false, fc, len); memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats)); ieee80211_rx(il->hw, skb); - il->alloc_rxb_page--; - rxb->page = NULL; } #define IL_DELAY_NEXT_SCAN_AFTER_ASSOC (HZ*6) |