On Mon, Sep 13, 2021 at 10:13:54AM +0200, Peter Zijlstra wrote: > On Sun, Sep 12, 2021 at 04:12:23AM +0000, cgel.zte@xxxxxxxxx wrote: > > From: Yang Yang <yang.yang29@xxxxxxxxxx> > > > > The old version sysctl has some problems. First, it allows set value > > bigger than 1, which is unnecessary. Second, it didn't follow the > > rule of capabilities. Thirdly, it didn't use static key. This new > > version fixes all the problems. > > Does any of that actually matter? For the first problem, I think the reason why sysctl_schedstats() only accepts 0 or 1, is suitbale for sysctl_child_runs_first(). Since task_fork_fair() only need sysctl_sched_child_runs_first to be zero or non-zero. For the second problem, I remember there is a rule: try to administration system through capilities but not depends on root identity. Just like sysctl_schedstats() or other sysctl_xx(). For the thirdly problem, sysctl_child_runs_first maynot changes often, but may accessed often, like static_key delayacct_key controlled by sysctl_delayacct(). Thanks!
