> -----Original Message----- > From: David S. Miller [mailto:[EMAIL PROTECTED] > Sent: Thursday, August 11, 2005 4:35 PM > To: [EMAIL PROTECTED] > Cc: Leonid Grossman; netdev@vger.kernel.org > Subject: Re: Super TSO performance drop > > From: Dmitry Yusupov <[EMAIL PROTECTED]> > Date: Thu, 11 Aug 2005 16:30:49 -0700 > > > But even with new TSO schema, this logic can not send more than > > MAX_SKB_FRAGS which at best case ~60K. With old TSO schema. > > I thought with SuperTSO we could send >> than 60K. And than > it could > > be very beneficial for us on some platforms where DMA setup is very > > cheap, since we could xmit up to 256 pages at once. > > Yes, MAX_SKB_FRAGS is the limit. We cannot build larger that > just under 64K frame due to IP header length field limitations. > > We have to encode the total length in the ipv4 header, so > there is no way to get around the 16-bit length limitation. >
Why the total length has to be in the header, there may be other ways to pass the total TSO length to the driver? MAX_SKB_FRAGS will be still a limitation though. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
