On Tue 24-10-17 03:02:09, tip-bot for Paul E. McKenney wrote: > Commit-ID: f79c3ad6189624c3de0ad5521610c9e22a1c33cf > Gitweb: > https://git.kernel.org/tip/f79c3ad6189624c3de0ad5521610c9e22a1c33cf > Author: Paul E. McKenney <paul...@linux.vnet.ibm.com> > AuthorDate: Wed, 30 Nov 2016 06:24:30 -0800 > Committer: Paul E. McKenney <paul...@linux.vnet.ibm.com> > CommitDate: Mon, 9 Oct 2017 14:25:17 -0700 > > sched,rcu: Make cond_resched() provide RCU quiescent state > > There is some confusion as to which of cond_resched() or > cond_resched_rcu_qs() should be added to long in-kernel loops. > This commit therefore eliminates the decision by adding RCU quiescent > states to cond_resched(). This commit also simplifies the code that > used to interact with cond_resched_rcu_qs(), and that now interacts with > cond_resched(), to reduce its overhead. This reduction is necessary to > allow the heavier-weight cond_resched_rcu_qs() mechanism to be invoked > everywhere that cond_resched() is invoked. > > Part of that reduction in overhead converts the jiffies_till_sched_qs > kernel parameter to read-only at runtime, thus eliminating the need for > bounds checking.
Thanks a lot Paul! I have just one question. Does the above mean that we can drop cond_resched_rcu_qs? Or there are still some scenarios when this is a better option? -- Michal Hocko SUSE Labs
