From: Frederic Weisbecker <frederic@kernel.org>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Michal Schmidt <mschmidt@redhat.com>,
Boqun Feng <boqun.feng@gmail.com>,
Joel Fernandes <joel@joelfernandes.org>,
Josh Triplett <josh@joshtriplett.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Neeraj Upadhyay <neeraj.upadhyay@amd.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Uladzislau Rezki <urezki@gmail.com>,
Zqiang <qiang.zhang1211@gmail.com>, rcu <rcu@vger.kernel.org>,
Frederic Weisbecker <frederic@kernel.org>
Subject: [PATCH 7/8] rcu/srcutiny: don't return before reenabling preemption
Date: Wed, 6 Nov 2024 15:59:10 +0100 [thread overview]
Message-ID: <20241106145911.35503-8-frederic@kernel.org> (raw)
In-Reply-To: <20241106145911.35503-1-frederic@kernel.org>
From: Michal Schmidt <mschmidt@redhat.com>
Code after the return statement is dead. Enable preemption before
returning from srcu_drive_gp().
This will be important when/if PREEMPT_AUTO (lazy resched) gets merged.
Fixes: 65b4a59557f6 ("srcu: Make Tiny SRCU explicitly disable preemption")
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
---
kernel/rcu/srcutiny.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c
index 549c03336ee9..4dcbf8aa80ff 100644
--- a/kernel/rcu/srcutiny.c
+++ b/kernel/rcu/srcutiny.c
@@ -122,8 +122,8 @@ void srcu_drive_gp(struct work_struct *wp)
ssp = container_of(wp, struct srcu_struct, srcu_work);
preempt_disable(); // Needed for PREEMPT_AUTO
if (ssp->srcu_gp_running || ULONG_CMP_GE(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max))) {
+ preempt_enable();
return; /* Already running or nothing to do. */
- preempt_enable();
}
/* Remove recently arrived callbacks and wait for readers. */
--
2.46.0
next prev parent reply other threads:[~2024-11-06 14:59 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-06 14:59 [PATCH 0/8] RCU fixes for v6.13 Frederic Weisbecker
2024-11-06 14:59 ` [PATCH 1/8] doc: Add rcuog kthreads to kernel-per-CPU-kthreads.rst Frederic Weisbecker
2024-11-06 14:59 ` [PATCH 2/8] rcu: Allow short-circuiting of synchronize_rcu_tasks_rude() Frederic Weisbecker
2024-11-06 14:59 ` [PATCH 3/8] rcu: Permit start_poll_synchronize_rcu*() with interrupts disabled Frederic Weisbecker
2024-11-06 14:59 ` [PATCH 4/8] rcutorture: Test start-poll primitives " Frederic Weisbecker
2024-11-06 14:59 ` [PATCH 5/8] doc: Remove kernel-parameters.txt entry for rcutorture.read_exit Frederic Weisbecker
2024-11-06 14:59 ` [PATCH 6/8] rcu-tasks: Remove open-coded one-byte cmpxchg() emulation Frederic Weisbecker
2024-11-06 14:59 ` Frederic Weisbecker [this message]
2024-11-06 14:59 ` [PATCH 8/8] rcu/kvfree: Fix data-race in __mod_timer / kvfree_call_rcu Frederic Weisbecker
2024-11-11 17:32 ` [PATCH 0/8] RCU fixes for v6.13 Neeraj Upadhyay
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=20241106145911.35503-8-frederic@kernel.org \
--to=frederic@kernel.org \
--cc=boqun.feng@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=mschmidt@redhat.com \
--cc=neeraj.upadhyay@amd.com \
--cc=paulmck@kernel.org \
--cc=qiang.zhang1211@gmail.com \
--cc=rcu@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=urezki@gmail.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.