From: "Paul E. McKenney" <paulmck@linux.ibm.com>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
jiangshanlai@gmail.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org,
"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH tip/core/rcu 20/41] kprobes: eplace synchronize_sched() with synchronize_rcu()
Date: Sun, 11 Nov 2018 19:19:16 -0800 [thread overview]
Message-ID: <20181112031916.GF4170@linux.ibm.com> (raw)
In-Reply-To: <20181112120048.12b3fb7549f4b292fea1eefd@kernel.org>
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" <paulmck@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")
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 <paulmck@linux.ibm.com>
> > Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
> > Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: Masami Hiramatsu <mhiramat@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 <mhiramat@kernel.org>
>
next prev parent reply other threads:[~2018-11-12 3:24 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-11 19:41 [PATCH tip/core/rcu 0/41] More RCU flavor consolidation cleanup for v4.21/v5.0 Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 01/41] rcu: Remove unused rcu_state externs Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 02/41] rcu: Fix rcu_{node,data} comments about gp_seq_needed Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 03/41] rcu: Eliminate synchronize_rcu_mult() Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 04/41] rcu: Consolidate the RCU update functions invoked by sync.c Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 05/41] sched/membarrier: Replace synchronize_sched() with synchronize_rcu() Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 06/41] sparc/oprofile: Convert timer_stop() to use synchronize_rcu() Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 07/41] s390/mm: Convert tlb_table_flush() to use call_rcu() Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 08/41] powerpc: Convert hugepd_free() " Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 09/41] crypto/pcrypt: Replace synchronize_rcu_bh() with synchronize_rcu() Paul E. McKenney
2018-11-16 5:56 ` Herbert Xu
2018-11-27 17:19 ` Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 10/41] drivers/ipmi: Replace synchronize_sched() " Paul E. McKenney
2018-11-12 15:38 ` Corey Minyard
2018-11-12 16:04 ` Paul E. McKenney
2018-11-12 16:15 ` Corey Minyard
2018-11-12 16:28 ` Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 11/41] ethernet/sis: " Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 12/41] ethernet/realtek: " Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 13/41] ethernet/intel/ixgbe: " Paul E. McKenney
2018-11-13 16:54 ` [Intel-wired-lan] " Bowers, AndrewX
2018-11-11 19:43 ` [PATCH tip/core/rcu 14/41] drivers/vhost: Replace synchronize_rcu_bh() " Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 15/41] cpufreq/intel_pstate: Replace synchronize_sched() " Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 16/41] cpufreq/cpufreq_governor: " Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 17/41] fs/file: " Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 18/41] tracing: Replace synchronize_sched() and call_rcu_sched() Paul E. McKenney
2018-11-12 2:09 ` Steven Rostedt
2018-11-11 19:43 ` [PATCH tip/core/rcu 19/41] main: Replace rcu_barrier_sched() with rcu_barrier() Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 20/41] kprobes: eplace synchronize_sched() with synchronize_rcu() Paul E. McKenney
2018-11-12 3:00 ` Masami Hiramatsu
2018-11-12 3:19 ` Paul E. McKenney [this message]
2018-11-13 18:08 ` Masami Hiramatsu
2018-11-13 19:22 ` Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 21/41] lockdep: Replace " Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 22/41] sched/membarrier: " Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 23/41] sched: Replace " Paul E. McKenney
2018-11-12 0:12 ` Peter Zijlstra
2018-11-12 0:45 ` Paul E. McKenney
2018-11-12 0:53 ` Peter Zijlstra
2018-11-12 1:47 ` Paul E. McKenney
2018-11-12 2:07 ` Peter Zijlstra
2018-11-12 2:24 ` Paul E. McKenney
2018-11-12 9:00 ` Peter Zijlstra
2018-11-12 13:28 ` Paul E. McKenney
2018-11-12 18:17 ` Peter Zijlstra
2018-11-12 20:20 ` Steven Rostedt
2018-11-12 22:21 ` Paul E. McKenney
2018-11-26 19:59 ` Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 24/41] modules: Replace synchronize_sched() and call_rcu_sched() Paul E. McKenney
2018-11-12 12:48 ` Jessica Yu
2018-11-12 16:31 ` Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 25/41] workqueue: Replace call_rcu_sched() with call_rcu() Paul E. McKenney
2018-11-13 15:48 ` Tejun Heo
2018-11-13 19:21 ` Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 26/41] events: Replace synchronize_sched() with synchronize_rcu() Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 27/41] percpu-refcount: Replace call_rcu_sched() with call_rcu() Paul E. McKenney
2018-11-13 15:48 ` Tejun Heo
2018-11-11 19:43 ` [PATCH tip/core/rcu 28/41] slab: Replace synchronize_sched() with synchronize_rcu() Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 29/41] mm: Replace call_rcu_sched() with call_rcu() Paul E. McKenney
2018-11-11 19:43 ` [PATCH tip/core/rcu 30/41] netfilter: Replace call_rcu_bh(), rcu_barrier_bh(), and synchronize_rcu_bh() Paul E. McKenney
2018-12-01 11:35 ` Pablo Neira Ayuso
2018-11-11 19:44 ` [PATCH tip/core/rcu 31/41] net/sched: Replace call_rcu_bh() and rcu_barrier_bh() Paul E. McKenney
2018-11-11 19:44 ` [PATCH tip/core/rcu 32/41] net/core: Replace call_rcu_bh() and synchronize_rcu_bh() Paul E. McKenney
2018-11-11 19:44 ` [PATCH tip/core/rcu 33/41] net/bridge: Replace call_rcu_bh() and rcu_barrier_bh() Paul E. McKenney
2018-11-13 0:29 ` Nikolay Aleksandrov
2018-11-11 19:44 ` [PATCH tip/core/rcu 34/41] percpu-rwsem: Replace synchronize_sched() with synchronize_rcu() Paul E. McKenney
2018-11-13 15:49 ` Tejun Heo
2018-11-11 19:44 ` [PATCH tip/core/rcu 35/41] types: Remove call_rcu_bh() and call_rcu_sched() Paul E. McKenney
2018-11-11 19:44 ` [PATCH tip/core/rcu 36/41] cgroups: Replace synchronize_sched() with synchronize_rcu() Paul E. McKenney
2018-11-13 15:50 ` Tejun Heo
2018-11-11 19:44 ` [PATCH tip/core/rcu 37/41] livepatch: " Paul E. McKenney
2018-11-11 19:44 ` [PATCH tip/core/rcu 38/41] net/core/skmsg: Replace call_rcu_sched() with call_rcu() Paul E. McKenney
2018-11-11 19:44 ` [PATCH tip/core/rcu 39/41] net/decnet: Replace rcu_barrier_bh() with rcu_barrier() Paul E. McKenney
2018-11-11 19:44 ` [PATCH tip/core/rcu 40/41] tools/kernel.h: Replace synchronize_sched() with synchronize_rcu() Paul E. McKenney
2018-11-11 19:44 ` [PATCH tip/core/rcu 41/41] rcutorture/formal: " Paul E. McKenney
2018-11-12 14:07 ` [PATCH tip/core/rcu 0/41] More RCU flavor consolidation cleanup for v4.21/v5.0 Mathieu Desnoyers
2018-11-12 16:01 ` Paul E. McKenney
2018-11-12 21:40 ` Sasha Levin
2018-11-12 22:16 ` Paul E. McKenney
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181112031916.GF4170@linux.ibm.com \
--to=paulmck@linux.ibm.com \
--cc=akpm@linux-foundation.org \
--cc=anil.s.keshavamurthy@intel.com \
--cc=davem@davemloft.net \
--cc=dhowells@redhat.com \
--cc=dipankar@in.ibm.com \
--cc=edumazet@google.com \
--cc=fweisbec@gmail.com \
--cc=jiangshanlai@gmail.com \
--cc=joel@joelfernandes.org \
--cc=josh@joshtriplett.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=mhiramat@kernel.org \
--cc=mingo@kernel.org \
--cc=naveen.n.rao@linux.ibm.com \
--cc=oleg@redhat.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).