On Wed, 2013-02-20 at 08:55 -0800, Eric Dumazet wrote: > > > It will make a huge difference, even on non pressure mode, as TCP > > > receive window will grow twice faster. > > > > Hmm, why does that depend on the allocation size? > > I guess you missed all the patches about skb->truesize on netdev Yeah, I don't follow netdev much any more... > > > - 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); > > > > Hmm, I don't quite understand -- that's not doing any copy? > > > > FWIW if you do the copy you should not "steal" the pages, then they'd be > > recycled in the RX ring right away. > > Code should just works, please read the following lines in the same > function.... > > /* If frame is small enough to fit in skb->head, pull it completely. > * If not, only pull ieee80211_hdr so that splice() or TCP coalesce > * are more efficient. > */ Oh, right, though I guess the comment is now wrong since practically every packet will be copied either here or in mac80211 (A-MSDUs are split up there) johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
