On Wed, Apr 25, 2007 at 01:45:19PM -0600, Eric W. Biederman wrote: > Andrew Morton <[EMAIL PROTECTED]> writes: > > > I note that the networking tree is adding new sysctls: > > > > <<<<<<< HEAD/include/linux/sysctl.h > > NET_IPV6_ACCEPT_SOURCE_ROUTE=25, > > ======= > > NET_IPV6_OPTIMISTIC_DAD=24, > > NET_IPV6_ACCEPT_SOURCE_ROUTE=25, > >>>>>>>> /include/linux/sysctl.h > > > > (Well, it's trying to - there are some git rejects in net-2.6.22) > > > > But we kind-of decided a while back to stop doing that and to > > use CTL_UNNUMBERED. > > > > Frankly, I don't 100% remember the thinking - Eric, can you please remind > > us? > > The thinking is this: > > Binary sysctl numbers are a problem because of patch conflicts like > the above, and the related user space breakage they cause. > > In practice no one uses binary sysctl numbers. > > So the policy should be to add new sysctl's using CTL_UNNUMBERED > (to prevent patch conflicts and user space breakage). > > There may be cases where someone actually needs the binary sysctl > interface. Once there is a demonstrated need we can go back > and very carefully add numbers for these very few cases, with > a strong review process. > > Adding binary sysctl numbers should be done as carefully as and with > as much review as adding syscall numbers, and distro kernels and other > stable kernels should never get a sysctl number backport until the > number first reaches Linus's tree. To avoid difference in meaning > between different kernels. > > Given that no one except on BSD uses the binary sysctl interface > anyway my personal preference is to just freeze it and to reduce the > number of binary sysctls we support if possible. > > Eric > - > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to [EMAIL PROTECTED] > More majordomo info at http://vger.kernel.org/majordomo-info.html
I did the optimistic dad sysctl, and have no strict use for numbered sysctls (I was just unaware of the policy). I'll work up a patch to use register_sysclt_table with CTL_UNNUMBERED in the next few days. Regards Neil - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
