freebsd-dev/sys/modules/cc/Makefile
Jonathan T. Looney bd79708dbf In the TCP stack, the hhook(9) framework provides hooks for kernel modules
to add actions that run when a TCP frame is sent or received on a TCP
session in the ESTABLISHED state. In the base tree, this functionality is
only used for the h_ertt module, which is used by the cc_cdg, cc_chd, cc_hd,
and cc_vegas congestion control modules.

Presently, we incur overhead to check for hooks each time a TCP frame is
sent or received on an ESTABLISHED TCP session.

This change adds a new compile-time option (TCP_HHOOK) to determine whether
to include the hhook(9) framework for TCP. To retain backwards
compatibility, I added the TCP_HHOOK option to every configuration file that
already defined "options INET". (Therefore, this patch introduces no
functional change. In order to see a functional difference, you need to
compile a custom kernel without the TCP_HHOOK option.) This change will
allow users to easily exclude this functionality from their kernel, should
they wish to do so.

Note that any users who use a custom kernel configuration and use one of the
congestion control modules listed above will need to add the TCP_HHOOK
option to their kernel configuration.

Reviewed by:	rrs, lstewart, hiren (previous version), sjg (makefiles only)
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D8185
2016-10-12 02:16:42 +00:00

21 lines
432 B
Makefile

# $FreeBSD$
SUBDIR= cc_cubic \
cc_dctcp \
cc_htcp
# Do we have the TCP_HHOOK symbol defined? If not, there is no point in
# building these modules by default.
# We will default to building these modules unless $OPT_INET is defined
# and does not contain the TCP_HHOOK option.
.if defined(ALL_MODULES) || ${OPT_INET:UTCP_HHOOK:MTCP_HHOOK} != ""
SUBDIR+= \
cc_cdg \
cc_chd \
cc_hd \
cc_vegas
.endif
.include <bsd.subdir.mk>