From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felix Fietkau Date: Mon, 24 Jan 2011 23:59:12 +0100 Subject: [ath9k-devel] Paged SKBs v/s copybreak. In-Reply-To: <4D3DFE49.7050500@candelatech.com> References: <4D3DFE49.7050500@candelatech.com> Message-ID: <4D3E0440.2000506@openwrt.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org On 2011-01-24 11:33 PM, Ben Greear wrote: > Some time back, I posted a patch to implement rx-copybreak for > ath9k. There were some other alternative patches that implemented > paged skbs. > > My patch had at least one real problem in that it needs to handle > arbitrary busses, not just pci. Seems that wouldn't be too hard > to implement, but I haven't bothered to date. It has been stable > for several weeks of testing on various pci-e and pci ath9k NICs. > > There was also a worry that for more normal use cases a paged skb > approach might be preferred over the skb-copybreak approach. > > I, and a few others, liked pure copybreak because it might work > around DMA start/stop issues in ath9k by ensuring that the hardware > never scribbles on packets handed up the stack. To me, this is > more important than performance, but then again, I have plenty of > CPU resources available on my systems. > > 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? > > Or should someone fix up the paged skb approach? I think finishing Jouni's patch and using that instead of the copybreak changes is the way to go, as it fixes the order-1 allocations without unnecessary data copying. - Felix