From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jouni Malinen Date: Tue, 25 Jan 2011 00:51:35 +0200 Subject: [ath9k-devel] Paged SKBs v/s copybreak. In-Reply-To: <4D3DFE49.7050500@candelatech.com> References: <4D3DFE49.7050500@candelatech.com> Message-ID: <1295909495.4581.50.camel@jm-desktop> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org On Mon, 2011-01-24 at 14:33 -0800, Ben Greear wrote: > So, I am hoping for some guidance from the core ath9k folks. Should > I attempt to fix my copybreak patch for non pci busses and re-post > it? My preference would be to use multiple RX buffers to receive long frames (chain RX descriptors with rs_more). I sent a preliminary patch for doing that. Unfortunately, I have not had time to complete this and probably in the near future. However, if someone has time available, it should be simple to get the initial version into suitable condition (just add support for the EDMA case where there may extra meta data in the beginning of the first RX buffer). That should already be enough to get the patch in and handle skb taking more than a page allocation issue. As the next step, mac80211 could be optimized to be able to handle A-MSDU RX without having to re-allocate and copy the received long buffers. The main benefit of this approach is that only the really long frames (A-MSDU RX) would suffer from the need to re-allocate and copy and even that A-MSDU RX case can be optimized by extending mac80211. In addition, this should make it easy to take larger A-MSDU size limit into use without extra cost for throughput reasons in the future. - Jouni