Date: Thu, 16 Aug 2007 20:23:02 GMT From: Andrew Gallatin <gallatin@cs.duke.edu> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/115586: options IPSEC disables TSO Message-ID: <200708162023.l7GKN2kM088100@www.freebsd.org> Resent-Message-ID: <200708162030.l7GKU2mB062981@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
>Number: 115586
>Category: kern
>Synopsis: options IPSEC disables TSO
>Confidential: no
>Severity: serious
>Priority: high
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Thu Aug 16 20:30:02 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator: Andrew Gallatin
>Release: 7.0-CURRENT
>Organization:
Myricom
>Environment:
FreeBSD venice 7.0-CURRENT FreeBSD 7.0-CURRENT #4: Thu Aug 16 15:46:45 EDT 2007 gallatin@venice:/usr/src/sys/amd64/compile/IPSEC amd64
>Description:
Simply compiling IPSEC into the kernel causes TCP Segmentation Offload
to be silently disabled for all connections, not just connections using IPSEC.
This causes a severe performance loss, especially on 10GbE networks.
>How-To-Repeat:
- Compile a kernel with 'options IPSEC' and device crypto
- boot the kernel
- notice that TSO stops working (can be verified by watching
the number of packets sent via systat -tcp 1)
>Fix:
A *hack*, not a fix, is attached. The hack enables normal connections to do TSO even when IPSEC is compiled in. Essentially, the TSO code needs to be a bit smarter, and check for more than just a null tp->t_inpcb->inp_sp. I know nothing about IPSEC, so I'm not able to propose a real fix.
Patch attached with submission follows:
Index: netinet/tcp_output.c
===================================================================
RCS file: /home/ncvs/src/sys/netinet/tcp_output.c,v
retrieving revision 1.140
diff -u -r1.140 tcp_output.c
--- netinet/tcp_output.c 3 Jul 2007 12:13:43 -0000 1.140
+++ netinet/tcp_output.c 16 Aug 2007 19:46:09 -0000
@@ -459,8 +459,8 @@
((tp->t_flags & TF_SIGNATURE) == 0) &&
tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
tp->t_inpcb->inp_options == NULL &&
- tp->t_inpcb->in6p_options == NULL &&
- tp->t_inpcb->inp_sp == NULL) {
+ tp->t_inpcb->in6p_options == NULL /* &&
+ tp->t_inpcb->inp_sp == NULL*/) {
tso = 1;
} else {
len = tp->t_maxseg;
>Release-Note:
>Audit-Trail:
>Unformatted:
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200708162023.l7GKN2kM088100>