![]() | |||||||||||||
Messages in this thread |
On Wed, 10 Jan 2007, Patrick McHardy wrote: > > In the x_tables case it really caused a lot of unnecessary confusion, > the recent connection tracking changes however needed new config > options since we're keeping the old implementation around for a few more > releases. It's too late now, but it _could_ have fairly easily been handled totally differently: namely by having the user-visible config options be INDEPENDENT of the actual back-end. The Kconfig language is actually pretty powerful for configuration issues, and the way to do this is relatively straightforward: config CONNTRACK tristate "Netfilter support" ... config NEW_CONTRACK_SUPPORT bool "Layer 3 Independent Connection tracking" ... config CONNTRACK_MARK bool 'Connection mark tracking support' depends on CONNTRACK ... config OLD_CONNTRACK_MARK bool depends on CONNTRACK_MARK && CONNTRACK && !NEW_CONTRACK_SUPPORT default y config NEW_CONNTRACK_MARK bool depends on CONNTRACK_MARK && CONNTRACK && NEW_CONTRACK_SUPPORT default y See? The _user_ just sees a single "CONNTRACK_MARK" option (that just depends on the *generic* CONNTRACK config option), but then the Kconfig file splits that into "OLD_CONNTRACK_MARK" or "NEW_CONNTRACK_MARK" depending on whether "NEW_CONTRACK_SUPPORT" was set or not. > It probably won't be necessary anymore to make changes like this in > the future, but in case it is I'll make sure to at least provide > compatibility options for a few releases. In general, I'd much rather see the config options impact what the "user experience" should be. Notice how the above does exactly that: all the USER really cares about whether the connection marks are enabled or not, and the "NEW_CONTRACK_SUPPORT" is _not_ part of the user-visible config (apart from the _one_ question that asks about which implementation you want to pick), but it is only used to pick which _implementation_ to choose. So making the Kconfig files more user-oriented and less implementation- oriented automatically solves the problem with config options that change names (because if the effect is the same, it should have the same name - regardless of how it is implemented!). Linus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
| Last update: 2007-01-10 18:01 [from the cache] ©2003-2008 | |||||||||||||