rcu.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: paulmck@kernel.org
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
	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,
	"Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH tip/core/rcu 5/5] rcu: Update __call_rcu() comments
Date: Fri, 14 Feb 2020 16:18:45 -0800	[thread overview]
Message-ID: <20200215001845.15432-5-paulmck@kernel.org> (raw)
In-Reply-To: <20200215001816.GA15284@paulmck-ThinkPad-P72>

From: "Paul E. McKenney" <paulmck@kernel.org>

The __call_rcu() function's header comment refers to a cpu argument
that no longer exists, and the comment of the return path from
rcu_nocb_try_bypass() ignores the non-no-CBs CPU case.  This comit
therefore update both comments.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/tree.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 48fba22..0a9de9f 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2642,12 +2642,7 @@ static void check_cb_ovld(struct rcu_data *rdp)
 	raw_spin_unlock_rcu_node(rnp);
 }
 
-/*
- * Helper function for call_rcu() and friends.  The cpu argument will
- * normally be -1, indicating "currently running CPU".  It may specify
- * a CPU only if that CPU is a no-CBs CPU.  Currently, only rcu_barrier()
- * is expected to specify a CPU.
- */
+/* Helper function for call_rcu() and friends.  */
 static void
 __call_rcu(struct rcu_head *head, rcu_callback_t func)
 {
@@ -2688,7 +2683,7 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func)
 	check_cb_ovld(rdp);
 	if (rcu_nocb_try_bypass(rdp, head, &was_alldone, flags))
 		return; // Enqueued onto ->nocb_bypass, so just leave.
-	/* If we get here, rcu_nocb_try_bypass() acquired ->nocb_lock. */
+	// If no-CBs CPU gets here, rcu_nocb_try_bypass() acquired ->nocb_lock.
 	rcu_segcblist_enqueue(&rdp->cblist, head);
 	if (__is_kfree_rcu_offset((unsigned long)func))
 		trace_rcu_kfree_callback(rcu_state.name, head,
-- 
2.9.5


      parent reply	other threads:[~2020-02-15  0:19 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-15  0:18 [PATCH tip/core/rcu 0/5] Callback-overload update for v5.7 Paul E. McKenney
2020-02-15  0:18 ` [PATCH tip/core/rcu 1/5] rcu: Clear ->core_needs_qs at GP end or self-reported QS paulmck
2020-02-15  0:18 ` [PATCH tip/core/rcu 2/5] rcu: React to callback overload by aggressively seeking quiescent states paulmck
2020-02-15  0:18 ` [PATCH tip/core/rcu 3/5] rcu: React to callback overload by boosting RCU readers paulmck
2020-02-15  0:18 ` [PATCH tip/core/rcu 4/5] rcu: Fix spelling mistake "leval" -> "level" paulmck
2020-02-15  0:18 ` paulmck [this message]

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=20200215001845.15432-5-paulmck@kernel.org \
    --to=paulmck@kernel.org \
    --cc=akpm@linux-foundation.org \
    --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=kernel-team@fb.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=mingo@kernel.org \
    --cc=oleg@redhat.com \
    --cc=peterz@infradead.org \
    --cc=rcu@vger.kernel.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).