From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next] asix: asix_rx_fixup surgery to reduce skb truesizes Date: Fri, 16 Mar 2012 01:52:30 -0700 (PDT) Message-ID: <20120316.015230.503523246344631871.davem@davemloft.net> References: <1331792312.2543.16.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, aurel-U/apLSaFET4dnm+yROfE0A@public.gmane.org, trond-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, grundler-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, pstew-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org To: eric.dumazet-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Return-path: In-Reply-To: <1331792312.2543.16.camel@edumazet-laptop> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org From: Eric Dumazet Date: Wed, 14 Mar 2012 23:18:32 -0700 > asix_rx_fixup() is complex, and does some unnecessary memory copies (at > least on x86 where NET_IP_ALIGN is 0) > > Also, it tends to provide skbs with a big truesize (4096+256 with > MTU=1500) to upper stack, so incoming trafic consume a lot of memory and > I noticed early packet drops because we hit socket rcvbuf too fast. > > Switch to a different strategy, using copybreak so that we provide nice > skbs to upper stack (including the NET_SKB_PAD to avoid future head > reallocations in some paths) > > With this patch, I no longer see packets drops or tcp collapses on > various tcp workload with a AX88772 adapter. > > Signed-off-by: Eric Dumazet Applied. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html