On Sun, 11 Nov 2018 19:19:16 -0800 "Paul E. McKenney" <[email protected]> wrote:
> On Mon, Nov 12, 2018 at 12:00:48PM +0900, Masami Hiramatsu wrote: > > On Sun, 11 Nov 2018 11:43:49 -0800 > > "Paul E. McKenney" <[email protected]> wrote: > > > > > Now that synchronize_rcu() waits for preempt-disable regions of code > > > as well as RCU read-side critical sections, synchronize_sched() can be > > > replaced by synchronize_rcu(). This commit therefore makes this change. > > > > Would you mean synchronize_rcu() can ensure that any interrupt handler > > (which should run under preempt-disable state) run out (even on > > non-preemptive > > kernel)? > > Yes, but only as of this merge window. See this commit: > > 3e3100989869 ("rcu: Defer reporting RCU-preempt quiescent states when > disabled") OK, I also found that now those are same. 45975c7d21a1 ("rcu: Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds") Acked-by: Masami Hiramatsu <[email protected]> Thank you! > > Don't try this in v4.19 or earlier, but v4.20 and later is OK. ;-) > > Thanx, Paul > > > If so, I agree with these changes. > > > > Thank you, > > > > > > > > Signed-off-by: Paul E. McKenney <[email protected]> > > > Cc: "Naveen N. Rao" <[email protected]> > > > Cc: Anil S Keshavamurthy <[email protected]> > > > Cc: "David S. Miller" <[email protected]> > > > Cc: Masami Hiramatsu <[email protected]> > > > --- > > > kernel/kprobes.c | 10 +++++----- > > > 1 file changed, 5 insertions(+), 5 deletions(-) > > > > > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > > > index 90e98e233647..08e31d863191 100644 > > > --- a/kernel/kprobes.c > > > +++ b/kernel/kprobes.c > > > @@ -229,7 +229,7 @@ static int collect_garbage_slots(struct > > > kprobe_insn_cache *c) > > > struct kprobe_insn_page *kip, *next; > > > > > > /* Ensure no-one is interrupted on the garbages */ > > > - synchronize_sched(); > > > + synchronize_rcu(); > > > > > > list_for_each_entry_safe(kip, next, &c->pages, list) { > > > int i; > > > @@ -1382,7 +1382,7 @@ static int register_aggr_kprobe(struct kprobe > > > *orig_p, struct kprobe *p) > > > if (ret) { > > > ap->flags |= KPROBE_FLAG_DISABLED; > > > list_del_rcu(&p->list); > > > - synchronize_sched(); > > > + synchronize_rcu(); > > > } > > > } > > > } > > > @@ -1597,7 +1597,7 @@ int register_kprobe(struct kprobe *p) > > > ret = arm_kprobe(p); > > > if (ret) { > > > hlist_del_rcu(&p->hlist); > > > - synchronize_sched(); > > > + synchronize_rcu(); > > > goto out; > > > } > > > } > > > @@ -1776,7 +1776,7 @@ void unregister_kprobes(struct kprobe **kps, int > > > num) > > > kps[i]->addr = NULL; > > > mutex_unlock(&kprobe_mutex); > > > > > > - synchronize_sched(); > > > + synchronize_rcu(); > > > for (i = 0; i < num; i++) > > > if (kps[i]->addr) > > > __unregister_kprobe_bottom(kps[i]); > > > @@ -1966,7 +1966,7 @@ void unregister_kretprobes(struct kretprobe **rps, > > > int num) > > > rps[i]->kp.addr = NULL; > > > mutex_unlock(&kprobe_mutex); > > > > > > - synchronize_sched(); > > > + synchronize_rcu(); > > > for (i = 0; i < num; i++) { > > > if (rps[i]->kp.addr) { > > > __unregister_kprobe_bottom(&rps[i]->kp); > > > -- > > > 2.17.1 > > > > > > > > > -- > > Masami Hiramatsu <[email protected]> > > > -- Masami Hiramatsu <[email protected]>
