From: Frederic Weisbecker <frederic@kernel.org>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>,
Boqun Feng <boqun.feng@gmail.com>,
Joel Fernandes <joel@joelfernandes.org>,
Neeraj Upadhyay <neeraj.upadhyay@amd.com>,
Uladzislau Rezki <urezki@gmail.com>,
Zqiang <qiang.zhang1211@gmail.com>, rcu <rcu@vger.kernel.org>,
"Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH 1/3] rcu: Rename jiffies_till_flush to jiffies_lazy_flush
Date: Wed, 15 Nov 2023 14:11:26 -0500 [thread overview]
Message-ID: <20231115191128.15615-2-frederic@kernel.org> (raw)
In-Reply-To: <20231115191128.15615-1-frederic@kernel.org>
The variable name jiffies_till_flush is too generic and therefore:
* It may shadow a global variable
* It doesn't tell on what it operates
Make the name more precise, along with the related APIs.
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
---
kernel/rcu/rcu.h | 8 ++++----
kernel/rcu/rcuscale.c | 6 +++---
kernel/rcu/tree_nocb.h | 22 +++++++++++-----------
3 files changed, 18 insertions(+), 18 deletions(-)
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index b531c33e9545..ff41423cd61c 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -541,11 +541,11 @@ enum rcutorture_type {
};
#if defined(CONFIG_RCU_LAZY)
-unsigned long rcu_lazy_get_jiffies_till_flush(void);
-void rcu_lazy_set_jiffies_till_flush(unsigned long j);
+unsigned long rcu_get_jiffies_lazy_flush(void);
+void rcu_set_jiffies_lazy_flush(unsigned long j);
#else
-static inline unsigned long rcu_lazy_get_jiffies_till_flush(void) { return 0; }
-static inline void rcu_lazy_set_jiffies_till_flush(unsigned long j) { }
+static inline unsigned long rcu_get_jiffies_lazy_flush(void) { return 0; }
+static inline void rcu_set_jiffies_lazy_flush(unsigned long j) { }
#endif
#if defined(CONFIG_TREE_RCU)
diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
index ffdb30495e3c..8db4fedaaa1e 100644
--- a/kernel/rcu/rcuscale.c
+++ b/kernel/rcu/rcuscale.c
@@ -764,9 +764,9 @@ kfree_scale_init(void)
if (kfree_by_call_rcu) {
/* do a test to check the timeout. */
- orig_jif = rcu_lazy_get_jiffies_till_flush();
+ orig_jif = rcu_get_jiffies_lazy_flush();
- rcu_lazy_set_jiffies_till_flush(2 * HZ);
+ rcu_set_jiffies_lazy_flush(2 * HZ);
rcu_barrier();
jif_start = jiffies;
@@ -775,7 +775,7 @@ kfree_scale_init(void)
smp_cond_load_relaxed(&rcu_lazy_test1_cb_called, VAL == 1);
- rcu_lazy_set_jiffies_till_flush(orig_jif);
+ rcu_set_jiffies_lazy_flush(orig_jif);
if (WARN_ON_ONCE(jiffies_at_lazy_cb - jif_start < 2 * HZ)) {
pr_alert("ERROR: call_rcu() CBs are not being lazy as expected!\n");
diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index 4efbf7333d4e..aecef51166c7 100644
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -256,6 +256,7 @@ static bool wake_nocb_gp(struct rcu_data *rdp, bool force)
return __wake_nocb_gp(rdp_gp, rdp, force, flags);
}
+#ifdef CONFIG_RCU_LAZY
/*
* LAZY_FLUSH_JIFFIES decides the maximum amount of time that
* can elapse before lazy callbacks are flushed. Lazy callbacks
@@ -264,21 +265,20 @@ static bool wake_nocb_gp(struct rcu_data *rdp, bool force)
* left unsubmitted to RCU after those many jiffies.
*/
#define LAZY_FLUSH_JIFFIES (10 * HZ)
-static unsigned long jiffies_till_flush = LAZY_FLUSH_JIFFIES;
+static unsigned long jiffies_lazy_flush = LAZY_FLUSH_JIFFIES;
-#ifdef CONFIG_RCU_LAZY
// To be called only from test code.
-void rcu_lazy_set_jiffies_till_flush(unsigned long jif)
+void rcu_set_jiffies_lazy_flush(unsigned long jif)
{
- jiffies_till_flush = jif;
+ jiffies_lazy_flush = jif;
}
-EXPORT_SYMBOL(rcu_lazy_set_jiffies_till_flush);
+EXPORT_SYMBOL(rcu_set_jiffies_lazy_flush);
-unsigned long rcu_lazy_get_jiffies_till_flush(void)
+unsigned long rcu_get_jiffies_lazy_flush(void)
{
- return jiffies_till_flush;
+ return jiffies_lazy_flush;
}
-EXPORT_SYMBOL(rcu_lazy_get_jiffies_till_flush);
+EXPORT_SYMBOL(rcu_get_jiffies_lazy_flush);
#endif
/*
@@ -299,7 +299,7 @@ static void wake_nocb_gp_defer(struct rcu_data *rdp, int waketype,
*/
if (waketype == RCU_NOCB_WAKE_LAZY &&
rdp->nocb_defer_wakeup == RCU_NOCB_WAKE_NOT) {
- mod_timer(&rdp_gp->nocb_timer, jiffies + jiffies_till_flush);
+ mod_timer(&rdp_gp->nocb_timer, jiffies + rcu_get_jiffies_lazy_flush());
WRITE_ONCE(rdp_gp->nocb_defer_wakeup, waketype);
} else if (waketype == RCU_NOCB_WAKE_BYPASS) {
mod_timer(&rdp_gp->nocb_timer, jiffies + 2);
@@ -482,7 +482,7 @@ static bool rcu_nocb_try_bypass(struct rcu_data *rdp, struct rcu_head *rhp,
// flush ->nocb_bypass to ->cblist.
if ((ncbs && !bypass_is_lazy && j != READ_ONCE(rdp->nocb_bypass_first)) ||
(ncbs && bypass_is_lazy &&
- (time_after(j, READ_ONCE(rdp->nocb_bypass_first) + jiffies_till_flush))) ||
+ (time_after(j, READ_ONCE(rdp->nocb_bypass_first) + rcu_get_jiffies_lazy_flush()))) ||
ncbs >= qhimark) {
rcu_nocb_lock(rdp);
*was_alldone = !rcu_segcblist_pend_cbs(&rdp->cblist);
@@ -723,7 +723,7 @@ static void nocb_gp_wait(struct rcu_data *my_rdp)
lazy_ncbs = READ_ONCE(rdp->lazy_len);
if (bypass_ncbs && (lazy_ncbs == bypass_ncbs) &&
- (time_after(j, READ_ONCE(rdp->nocb_bypass_first) + jiffies_till_flush) ||
+ (time_after(j, READ_ONCE(rdp->nocb_bypass_first) + rcu_get_jiffies_lazy_flush()) ||
bypass_ncbs > 2 * qhimark)) {
flush_bypass = true;
} else if (bypass_ncbs && (lazy_ncbs != bypass_ncbs) &&
--
2.42.1
next prev parent reply other threads:[~2023-11-15 19:11 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-15 19:11 [PATCH 0/3] rcu/nocb updates v2 Frederic Weisbecker
2023-11-15 19:11 ` Frederic Weisbecker [this message]
2023-11-15 19:11 ` [PATCH 2/3] rcu/nocb: Remove needless LOAD-ACQUIRE Frederic Weisbecker
2023-11-15 19:11 ` [PATCH 3/3] rcu/nocb: Remove needless full barrier after callback advancing Frederic Weisbecker
2023-12-05 4:20 ` [PATCH 0/3] rcu/nocb updates v2 Paul E. McKenney
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