On Monday, December 01, 2014 07:19:13 AM Alfred Perlstein wrote: > John, > > Will work on a new revision based on feedback. > > Two things to note however: > > Already explored the idea of using kernel_sysctlbyname but rejected due to > following: > > It makes little sense to have a rw sysctl that only takes effect "some > times". This violates POLA at the expense of making code appear cleaner. > Expectation is that writable sysctls take effect or are read only. They are > not to be "write sometimes" unless we are to introduce a new flag. Instead > of going to a confusing model we consider some form of rw sysctl that can > set itself ro somehow. Otherwise people will be confused as to why nic > queues says N while actually M. What the rw->ro api would look like I have > no idea. Suggestions?
This is only somewhat true. In the near distant future we will have a devctl tool which would let you do 'devctl detach igb0 && devctl attach igb0' which would honor your post-boot setting of hw.igb.num_queues. Instead what is important to understand about this particular sysctl node is that it only takes affect when a device is attached. However, there are other control knobs that also only affect future operations and not existing instances of objects, so I don't think this is that big of a leap. -- John Baldwin _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
