From: Lai Jiangshan <jiangshanlai@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: rcu@vger.kernel.org, x86@kernel.org,
Lai Jiangshan <jiangshan.ljs@antgroup.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Frederic Weisbecker <frederic@kernel.org>,
Neeraj Upadhyay <quic_neeraju@quicinc.com>,
Joel Fernandes <joel@joelfernandes.org>,
Josh Triplett <josh@joshtriplett.org>,
Boqun Feng <boqun.feng@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Zqiang <qiang.zhang1211@gmail.com>
Subject: [PATCH V2 05/11] rcu: Make rcu_read_unlock_special() global
Date: Sun, 7 Apr 2024 17:05:52 +0800 [thread overview]
Message-ID: <20240407090558.3395-6-jiangshanlai@gmail.com> (raw)
In-Reply-To: <20240407090558.3395-1-jiangshanlai@gmail.com>
From: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Make it global so that it can be used in the future inlined rcu_read_unlock().
Make it exported so that the inlined rcu_read_unlock() can be used in modules.
Make it taking a void-argument so that the caller can reduce instructions
obtaining the "current" task and it can be used in THUNK later.
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
---
include/linux/rcupdate.h | 2 ++
kernel/rcu/tree_plugin.h | 7 ++++---
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index ebe9bfc700bb..328667ae8086 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -68,6 +68,8 @@ static inline bool same_state_synchronize_rcu(unsigned long oldstate1, unsigned
#ifdef CONFIG_PREEMPT_RCU
+void rcu_read_unlock_special(void);
+
void __rcu_read_lock(void);
void __rcu_read_unlock(void);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 3dbd5609185e..880b3fef1158 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -104,7 +104,6 @@ static void __init rcu_bootup_announce_oddness(void)
static void rcu_report_exp_rnp(struct rcu_node *rnp, bool wake);
static bool sync_rcu_exp_done(struct rcu_node *rnp);
-static void rcu_read_unlock_special(struct task_struct *t);
#define set_rcu_preempt_special(reason) do { \
WRITE_ONCE(current->rcu_read_unlock_special.b.reason, true); \
@@ -427,7 +426,7 @@ void __rcu_read_unlock(void)
if (rcu_preempt_read_exit() == 0) {
barrier(); // critical-section exit before .s check.
if (unlikely(READ_ONCE(t->rcu_read_unlock_special.s)))
- rcu_read_unlock_special(t);
+ rcu_read_unlock_special();
}
if (IS_ENABLED(CONFIG_PROVE_LOCKING)) {
int rrln = rcu_preempt_depth();
@@ -627,8 +626,9 @@ static void rcu_preempt_deferred_qs_handler(struct irq_work *iwp)
* notify RCU core processing or task having blocked during the RCU
* read-side critical section.
*/
-static void rcu_read_unlock_special(struct task_struct *t)
+void rcu_read_unlock_special(void)
{
+ struct task_struct *t = current;
unsigned long flags;
bool irqs_were_disabled;
bool preempt_bh_were_disabled =
@@ -684,6 +684,7 @@ static void rcu_read_unlock_special(struct task_struct *t)
}
rcu_preempt_deferred_qs_irqrestore(t, flags);
}
+EXPORT_SYMBOL_GPL(rcu_read_unlock_special);
/*
* Check that the list of blocked tasks for the newly completed grace
--
2.19.1.6.gb485710b
next prev parent reply other threads:[~2024-04-07 9:03 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-07 9:05 [PATCH V2 00/11] rcu/x86: Use per-cpu rcu preempt count Lai Jiangshan
2024-04-07 9:05 ` [PATCH V2 01/11] lib: Use rcu_preempt_depth() to replace current->rcu_read_lock_nesting Lai Jiangshan
2024-04-07 9:05 ` [PATCH V2 02/11] rcu: Move rcu_preempt_depth_set() to rcupdate.h Lai Jiangshan
2024-04-07 9:05 ` [PATCH V2 03/11] rcu: Reorder tree_exp.h after tree_plugin.h Lai Jiangshan
2024-04-23 17:58 ` Joel Fernandes
2024-04-24 2:47 ` Lai Jiangshan
2024-04-07 9:05 ` [PATCH V2 04/11] rcu: Add macros set_rcu_preempt_special() and clear_rcu_preempt_special() Lai Jiangshan
2024-04-07 9:05 ` Lai Jiangshan [this message]
2024-04-07 9:05 ` [PATCH V2 06/11] rcu: Rename marco __LINUX_RCU_H to __KERNEL_RCU_H Lai Jiangshan
2024-04-07 9:05 ` [PATCH V2 07/11] sched/core: Add rcu_preempt_switch() Lai Jiangshan
2024-04-07 9:05 ` [PATCH V2 08/11] x86/entry: Merge thunk_64.S and thunk_32.S into thunk.S Lai Jiangshan
2024-04-07 9:05 ` [PATCH V2 09/11] rcu: Implement PCPU_RCU_PREEMPT_COUNT framework Lai Jiangshan
2024-04-23 18:19 ` Joel Fernandes
2024-04-24 3:02 ` Lai Jiangshan
2024-04-07 9:05 ` [PATCH V2 10/11] x86/rcu: Add rcu_preempt_count Lai Jiangshan
2024-04-23 18:09 ` Joel Fernandes
2024-04-24 2:53 ` Lai Jiangshan
2024-04-07 9:05 ` [PATCH V2 11/11] x86/rcu: Add THUNK rcu_read_unlock_special_thunk Lai Jiangshan
2024-04-23 17:26 ` Joel Fernandes
2024-04-24 2:43 ` Lai Jiangshan
2024-05-20 20:03 ` [PATCH V2 00/11] rcu/x86: Use per-cpu rcu preempt count 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=20240407090558.3395-6-jiangshanlai@gmail.com \
--to=jiangshanlai@gmail.com \
--cc=boqun.feng@gmail.com \
--cc=frederic@kernel.org \
--cc=jiangshan.ljs@antgroup.com \
--cc=joel@joelfernandes.org \
--cc=josh@joshtriplett.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=paulmck@kernel.org \
--cc=peterz@infradead.org \
--cc=qiang.zhang1211@gmail.com \
--cc=quic_neeraju@quicinc.com \
--cc=rcu@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=x86@kernel.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;
as well as URLs for NNTP newsgroup(s).