From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Berg Subject: handing cloned frames to netif_rx()? Date: Fri, 11 Jan 2008 02:17:26 +0100 Message-ID: <1200014246.3861.148.camel@johannes.berg> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-otqGlbx99hSwJc/dvnvo" Cc: Ron Rindjunsky , linux-wireless To: netdev Return-path: Sender: linux-wireless-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org --=-otqGlbx99hSwJc/dvnvo Content-Type: text/plain Content-Transfer-Encoding: quoted-printable In 802.11n, there is a case where multiple data frames are received aggregated into a single frame (A-MSDU). Currently, we copy each of these frames out into their own skb, but because of the alignment with that etc. I started to think that we could simply pass up a clone of the original skb with start/length adjusted properly so that it windows only the contained packet. The buffer would be shared but the data within the original window (starting with the 802.3 header) could even be written to, it won't be needed again by mac80211 once it's handed off to netif_rx(). The skb will obviously have lots of head- and tailroom but that space would be part of other packets. Is it ok to do this? Will something freak out if we pass a cloned skb to netif_rx()? johannes --=-otqGlbx99hSwJc/dvnvo Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIVAwUAR4bDpKVg1VMiehFYAQLI7g/+PrcQAuCq/4RbYeU1yfqLEzHnbCtNjpMQ +5qBaZLcAi5AzpHqaR/7z3Ea39ciwSxhT3v3WCEPMZyPjP78efLFNKoZ5TCvVvFs eOsgQHzq+POAvZ2fCjINXKFab35O4W2RejHMLlBDG62adh2LL8XRUnIvItQrqLc8 oXYSGahleuSIC4mBg4mGAOKPHZbJkrPmDLGQEqywAgPziMGIyv/uLkiCsOjr43yk nFjLFzkPz1wQMrpbYcVKfu0JYaVVtVcUYS9RqPKMAKgmyTuh5mrt3j0kV7zjKZsO MnewOAa9EX98wXvhx0Se6ofz7rtFlSI3bTLWDo55CzczhUX9EayGohLZtypatEs0 xG1j+lKRiW48n6KkSvmOLQJxZ+7bTlOBebSuqjDOBrjye3zBU0oiQ7xjL2I5Q0Nu LB3W/+EybkSnC4DG9CGoCzW/4L+wontSmny1l75MyCPTf3Yxi151nJf4E/e/JhAa bu86f0MFdXEDX8sTc3Lm+46MQJnUj4yKvBqoG6ob1VTWV7Ce4MJazRqymRBiZPUa 8KdCbq5XkDaphqkEiJ85/BlRr86Wa13DvP6jxJ8A3+NNGthg3acB+Nizmku+L1Hd sEIpREIjHVwCbCX0BR1+anKZoog6ncahsUTIq92KH8A0tv1AObyhJTX2DVDuhu5v VtAMrnTa9o8= =9bzi -----END PGP SIGNATURE----- --=-otqGlbx99hSwJc/dvnvo--