Re: 3.7.8/amd64 full interrupt hangs due to iwlwifi under big nfs copies out
From: Eric Dumazet <hidden>
Date: 2013-02-20 15:11:07
Also in:
linux-wireless
Subsystem:
networking drivers (wireless), the rest · Maintainers:
Johannes Berg, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2013-06-19 · Re: 3.7.8/amd64 full interrupt hangs due to iwlwifi under big nfs copies out · Stanislaw Gruszka <hidden>
- 2013-06-18 · Re: 3.7.8/amd64 full interrupt hangs due to iwlwifi under big nfs copies out · Johannes Berg <johannes@sipsolutions.net>
- 2013-06-18 · Re: 3.7.8/amd64 full interrupt hangs due to iwlwifi under big nfs copies out · Eric Dumazet <hidden>
- 2013-02-20 · Re: 3.7.8/amd64 full interrupt hangs due to iwlwifi under big nfs copies out · Johannes Berg <johannes@sipsolutions.net>
- 2013-02-20 · Re: 3.7.8/amd64 full interrupt hangs due to iwlwifi under big nfs copies out · Eric Dumazet <hidden>
On Wed, 2013-02-20 at 10:15 +0100, Johannes Berg wrote:
OTOH, this affects the protocol, and when you really can't allocate any order-1 pages you pointed out yourself that many other things also won't work, so I'm not really sure it makes a big difference if we change the driver?
It will make a huge difference, even on non pressure mode, as TCP receive window will grow twice faster. Unless wifi speed reaches 10Gbps, following patch should do the trick
diff --git a/drivers/net/wireless/iwlwifi/dvm/rx.c b/drivers/net/wireless/iwlwifi/dvm/rx.c
index a4eed20..77a3ee3 100644
--- a/drivers/net/wireless/iwlwifi/dvm/rx.c
+++ b/drivers/net/wireless/iwlwifi/dvm/rx.c@@ -750,7 +750,12 @@ static void iwlagn_pass_packet_to_mac80211(struct iwl_priv *priv, /* Dont use dev_alloc_skb(), we'll have enough headroom once * ieee80211_hdr pulled. */ - skb = alloc_skb(128, GFP_ATOMIC); + fraglen = 128; + /* if we use order-1 pages, copy to get better TCP performance */ + if (rxb->truesize > PAGE_SIZE) + fraglen = max_t(unsigned, fraglen, len); + + skb = alloc_skb(fraglen, GFP_ATOMIC); if (!skb) { IWL_ERR(priv, "alloc_skb failed\n"); return;