From: Lai Jiangshan <laijs@cn.fujitsu.com>
To: <linux-kernel@vger.kernel.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>,
Josh Triplett <josh@joshtriplett.org>,
Steven Rostedt <rostedt@goodmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Subject: [PATCH] rcu_tree: avoid touch rnp->completed when starts a new GP
Date: Tue, 13 Jan 2015 15:30:34 +0800 [thread overview]
Message-ID: <1421134234-3418-1-git-send-email-laijs@cn.fujitsu.com> (raw)
In rcu_gp_init(), rnp->completed equals to rsp->completed in THEORY,
we don't need to touch it normally. If something goes wrong,
it will complain and fixup rnp->completed and avoid oops.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
kernel/rcu/tree.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 7680fc2..ea6dc28 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1639,8 +1639,8 @@ static int rcu_gp_init(struct rcu_state *rsp)
rcu_preempt_check_blocked_tasks(rnp);
rnp->qsmask = rnp->qsmaskinit;
ACCESS_ONCE(rnp->gpnum) = rsp->gpnum;
- WARN_ON_ONCE(rnp->completed != rsp->completed);
- ACCESS_ONCE(rnp->completed) = rsp->completed;
+ if (WARN_ON_ONCE(rnp->completed != rsp->completed))
+ ACCESS_ONCE(rnp->completed) = rsp->completed;
if (rnp == rdp->mynode)
(void)__note_gp_changes(rsp, rnp, rdp);
rcu_preempt_boost_start_gp(rnp);
--
2.1.0
next reply other threads:[~2015-01-13 7:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-13 7:30 Lai Jiangshan [this message]
2015-01-13 9:36 ` 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=1421134234-3418-1-git-send-email-laijs@cn.fujitsu.com \
--to=laijs@cn.fujitsu.com \
--cc=josh@joshtriplett.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=rostedt@goodmis.org \
/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
all inboxes | Powered by JetHome®