On Wednesday, December 07, 2016 02:15:49 PM Mark Johnston wrote: > On Wed, Dec 07, 2016 at 01:26:47PM -0800, Gleb Smirnoff wrote: > > On Tue, Dec 06, 2016 at 10:52:45PM +0000, Mark Johnston wrote: > > M> Author: markj > > M> Date: Tue Dec 6 22:52:45 2016 > > M> New Revision: 309658 > > M> URL: https://svnweb.freebsd.org/changeset/base/309658 > > M> > > M> Log: > > M> Provide dummy sysctls for v_cache_count and v_tcached. > > M> > > M> Some utilities (notably top(1)) exit if any of their input sysctls > > don't > > M> exist, and the removal of the above-mentioned PG_CACHE-related sysctls > > M> makes it difficult to run such utilities on different versions of the > > M> kernel without recompiling. > > M> > > M> Requested by: bde > > M> > > M> Modified: > > M> head/sys/vm/vm_meter.c > > M> > > M> Modified: head/sys/vm/vm_meter.c > > M> > > ============================================================================== > > M> --- head/sys/vm/vm_meter.c Tue Dec 6 22:48:28 2016 > > (r309657) > > M> +++ head/sys/vm/vm_meter.c Tue Dec 6 22:52:45 2016 > > (r309658) > > M> @@ -314,3 +314,14 @@ VM_STATS_VM(v_forkpages, "VM pages affec > > M> VM_STATS_VM(v_vforkpages, "VM pages affected by vfork()"); > > M> VM_STATS_VM(v_rforkpages, "VM pages affected by rfork()"); > > M> VM_STATS_VM(v_kthreadpages, "VM pages affected by fork() by kernel"); > > M> + > > M> +#ifndef BURN_BRIDGES > > M> +/* > > M> + * Provide compatibility sysctls for the benefit of old utilities which > > exit > > M> + * with an error if they cannot be found. > > M> + */ > > M> +SYSCTL_UINT(_vm_stats_vm, OID_AUTO, v_cache_count, CTLFLAG_RD, > > M> + (u_int *)NULL, 0, "Dummy for compatibility"); > > M> +SYSCTL_UINT(_vm_stats_vm, OID_AUTO, v_tcached, CTLFLAG_RD, > > M> + (u_int *)NULL, 0, "Dummy for compatibility"); > > M> +#endif > > > > IMHO, there should be some garbage collecting timeout for them. I'd suggest > > to > > delete them from head after stable/12 branch is forked. > > The intent was to improve compatibility with old userlands, not just to > help bridge the transition from 11.0 to 12.0. In general I'm all for > removing cruft, but these sysctls are unobtrusive and I don't see any > reason to remove them in a specific time frame provided that nothing > else breaks compatibility for top(1) (and vmstat(8)). Please feel free > to add a timeout if you still disagree, though.
I would suggest sticking them under COMPAT_FREEBSD11 then. That would give users control via the COMPAT_FREEBSD<x> options the way we do with other compat shims. The only nit is you need to add the COMPAT_FREEBSD11 option first (probably in a separate commit). -- John Baldwin _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"