On 06/03/13 23:00, Andre Oppermann wrote: > Author: andre > Date: Mon Jun 3 13:00:33 2013 > New Revision: 251297 > URL: http://svnweb.freebsd.org/changeset/base/251297 > > Log: > Specify a maximum TSO length limiting the segment chain to what the > Xen host side can handle after defragmentation. > > This prevents the driver from throwing away too long TSO chains and > improves the performance on Amazon AWS instances with 10GigE virtual > interfaces to the normally expected throughput. > > Submitted by: cperciva (earlier version) > Reviewed by: cperciva > Tested by: cperciva > MFC after: 1 week > > Modified: > head/sys/dev/xen/netfront/netfront.c > > Modified: head/sys/dev/xen/netfront/netfront.c > ============================================================================== > --- head/sys/dev/xen/netfront/netfront.c Mon Jun 3 12:55:13 2013 > (r251296) > +++ head/sys/dev/xen/netfront/netfront.c Mon Jun 3 13:00:33 2013 > (r251297) > @@ -134,6 +134,7 @@ static const int MODPARM_rx_flip = 0; > * to mirror the Linux MAX_SKB_FRAGS constant. > */ > #define MAX_TX_REQ_FRAGS (65536 / PAGE_SIZE + 2) > +#define NF_TSO_MAXBURST ((IP_MAXPACKET / PAGE_SIZE) * MCLBYTES)
For posterity's sake, can you and/or Colin please elaborate on how this value was determined and what it is dependent upon? Could a newer version of Xen remove the need for this reduced limit? Cheers, Lawrence _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"