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author | rwatson <rwatson@FreeBSD.org> | 2004-08-28 15:11:13 +0000 |
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committer | rwatson <rwatson@FreeBSD.org> | 2004-08-28 15:11:13 +0000 |
commit | 69e658ec5ae80337e0ce0fd7124b7a4344161a9c (patch) | |
tree | 6ad9ef1cb5054a0cc25ff444831031fb77cb783f /sys/conf/options | |
parent | bb60ef092768837ab9067cd484bec4f3c179c5a5 (diff) | |
download | FreeBSD-src-69e658ec5ae80337e0ce0fd7124b7a4344161a9c.zip FreeBSD-src-69e658ec5ae80337e0ce0fd7124b7a4344161a9c.tar.gz |
Change the default disposition of debug.mpsafenet from 0 to 1, which
will cause the network stack to operate without the Giant lock by
default. This change has the potential to improve performance by
increasing parallelism and decreasing latency in network processing.
Due to the potential exposure of existing or new bugs, the following
compatibility functionality is maintained:
- It is still possible to disable Giant-free operation by setting
debug.mpsafenet to 0 in loader.conf.
- Add "options NET_WITH_GIANT", which will restore the default value of
debug.mpsafenet to 0, and is intended for use on systems compiled with
known unsafe components, or where a more conservative configuration is
desired.
- Add a new declaration, NET_NEEDS_GIANT("componentname"), which permits
kernel components to declare dependence on Giant over the network
stack. If the declaration is made by a preloaded module or a compiled
in component, the disposition of debug.mpsafenet will be set to 0 and
a warning concerning performance degraded operation printed to the
console. If it is declared by a loadable kernel module after boot, a
warning is displayed but the disposition cannot be changed. This is
implemented by defining a new SYSINIT() value, SI_SUB_SETTINGS, which
is intended for the processing of configuration choices after tunables
are read in and the console is available to generate errors, but
before much else gets going.
This compatibility behavior will go away when we've finished the last
of the locking work and are confident that operation is correct.
Diffstat (limited to 'sys/conf/options')
-rw-r--r-- | sys/conf/options | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/sys/conf/options b/sys/conf/options index d0d7990..2ef8b20 100644 --- a/sys/conf/options +++ b/sys/conf/options @@ -361,6 +361,7 @@ LIBMCHAIN MBUF_STRESS_TEST opt_mbuf_stress_test.h NCP NETATALK opt_atalk.h +NET_WITH_GIANT opt_net.h PPP_BSDCOMP opt_ppp.h PPP_DEFLATE opt_ppp.h PPP_FILTER opt_ppp.h |