On Tue, Nov 13, 2018 at 10:08:36AM -0800, Masami Hiramatsu wrote:
> On Sun, 11 Nov 2018 19:19:16 -0800
> "Paul E. McKenney" <paul...@linux.ibm.com> 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" <paul...@linux.ibm.com> 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 <mhira...@kernel.org>
Applied, thank you!
Thanx, Paul
> 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 <paul...@linux.ibm.com>
> > > > Cc: "Naveen N. Rao" <naveen.n....@linux.ibm.com>
> > > > Cc: Anil S Keshavamurthy <anil.s.keshavamur...@intel.com>
> > > > Cc: "David S. Miller" <da...@davemloft.net>
> > > > Cc: Masami Hiramatsu <mhira...@kernel.org>
> > > > ---
> > > > 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 <mhira...@kernel.org>
> > >
> >
>
>
> --
> Masami Hiramatsu <mhira...@kernel.org>
>
