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From: Frederic Weisbecker <frederic@kernel.org>
To: LKML <linux-kernel@vger.kernel.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>,
	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>,
	Steven Rostedt <rostedt@goodmis.org>,
	Uladzislau Rezki <urezki@gmail.com>,
	Zqiang <qiang.zhang1211@gmail.com>, rcu <rcu@vger.kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Andrii Nakryiko <andrii@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Kent Overstreet <kent.overstreet@linux.dev>,
	bpf@vger.kernel.org, Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>,
	Frederic Weisbecker <frederic@kernel.org>
Subject: [PATCH 04/16] srcu: Renaming in preparation for additional reader flavor
Date: Tue, 12 Nov 2024 15:51:47 +0100	[thread overview]
Message-ID: <20241112145159.23032-5-frederic@kernel.org> (raw)
In-Reply-To: <20241112145159.23032-1-frederic@kernel.org>

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

Currently, there are only two flavors of readers, normal and NMI-safe.
A number of fields, functions, and types reflect this restriction.
This renaming-only commit prepares for the addition of light-weight
(as in memory-barrier-free) readers.  OK, OK, there is also a drive-by
white-space fixeup!

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: <bpf@vger.kernel.org>
Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
---
 include/linux/srcu.h     | 21 ++++++++++-----------
 include/linux/srcutree.h |  2 +-
 kernel/rcu/srcutree.c    | 22 +++++++++++-----------
 3 files changed, 22 insertions(+), 23 deletions(-)

diff --git a/include/linux/srcu.h b/include/linux/srcu.h
index 835bbb2d1f88..06728ef6f32a 100644
--- a/include/linux/srcu.h
+++ b/include/linux/srcu.h
@@ -181,10 +181,9 @@ static inline int srcu_read_lock_held(const struct srcu_struct *ssp)
 #define SRCU_NMI_SAFE		0x2
 
 #if defined(CONFIG_PROVE_RCU) && defined(CONFIG_TREE_SRCU)
-void srcu_check_nmi_safety(struct srcu_struct *ssp, bool nmi_safe);
+void srcu_check_read_flavor(struct srcu_struct *ssp, int read_flavor);
 #else
-static inline void srcu_check_nmi_safety(struct srcu_struct *ssp,
-					 bool nmi_safe) { }
+static inline void srcu_check_read_flavor(struct srcu_struct *ssp, int read_flavor) { }
 #endif
 
 
@@ -245,7 +244,7 @@ static inline int srcu_read_lock(struct srcu_struct *ssp) __acquires(ssp)
 {
 	int retval;
 
-	srcu_check_nmi_safety(ssp, false);
+	srcu_check_read_flavor(ssp, false);
 	retval = __srcu_read_lock(ssp);
 	srcu_lock_acquire(&ssp->dep_map);
 	return retval;
@@ -262,7 +261,7 @@ static inline int srcu_read_lock_nmisafe(struct srcu_struct *ssp) __acquires(ssp
 {
 	int retval;
 
-	srcu_check_nmi_safety(ssp, true);
+	srcu_check_read_flavor(ssp, true);
 	retval = __srcu_read_lock_nmisafe(ssp);
 	rcu_try_lock_acquire(&ssp->dep_map);
 	return retval;
@@ -274,7 +273,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) __acquires(ssp)
 {
 	int retval;
 
-	srcu_check_nmi_safety(ssp, false);
+	srcu_check_read_flavor(ssp, false);
 	retval = __srcu_read_lock(ssp);
 	return retval;
 }
@@ -303,7 +302,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) __acquires(ssp)
 static inline int srcu_down_read(struct srcu_struct *ssp) __acquires(ssp)
 {
 	WARN_ON_ONCE(in_nmi());
-	srcu_check_nmi_safety(ssp, false);
+	srcu_check_read_flavor(ssp, false);
 	return __srcu_read_lock(ssp);
 }
 
@@ -318,7 +317,7 @@ static inline void srcu_read_unlock(struct srcu_struct *ssp, int idx)
 	__releases(ssp)
 {
 	WARN_ON_ONCE(idx & ~0x1);
-	srcu_check_nmi_safety(ssp, false);
+	srcu_check_read_flavor(ssp, false);
 	srcu_lock_release(&ssp->dep_map);
 	__srcu_read_unlock(ssp, idx);
 }
@@ -334,7 +333,7 @@ static inline void srcu_read_unlock_nmisafe(struct srcu_struct *ssp, int idx)
 	__releases(ssp)
 {
 	WARN_ON_ONCE(idx & ~0x1);
-	srcu_check_nmi_safety(ssp, true);
+	srcu_check_read_flavor(ssp, true);
 	rcu_lock_release(&ssp->dep_map);
 	__srcu_read_unlock_nmisafe(ssp, idx);
 }
@@ -343,7 +342,7 @@ static inline void srcu_read_unlock_nmisafe(struct srcu_struct *ssp, int idx)
 static inline notrace void
 srcu_read_unlock_notrace(struct srcu_struct *ssp, int idx) __releases(ssp)
 {
-	srcu_check_nmi_safety(ssp, false);
+	srcu_check_read_flavor(ssp, false);
 	__srcu_read_unlock(ssp, idx);
 }
 
@@ -360,7 +359,7 @@ static inline void srcu_up_read(struct srcu_struct *ssp, int idx)
 {
 	WARN_ON_ONCE(idx & ~0x1);
 	WARN_ON_ONCE(in_nmi());
-	srcu_check_nmi_safety(ssp, false);
+	srcu_check_read_flavor(ssp, false);
 	__srcu_read_unlock(ssp, idx);
 }
 
diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h
index ed57598394de..ab7d8d215b84 100644
--- a/include/linux/srcutree.h
+++ b/include/linux/srcutree.h
@@ -25,7 +25,7 @@ struct srcu_data {
 	/* Read-side state. */
 	atomic_long_t srcu_lock_count[2];	/* Locks per CPU. */
 	atomic_long_t srcu_unlock_count[2];	/* Unlocks per CPU. */
-	int srcu_nmi_safety;			/* NMI-safe srcu_struct structure? */
+	int srcu_reader_flavor;			/* Reader flavor for srcu_struct structure? */
 
 	/* Update-side state. */
 	spinlock_t __private lock ____cacheline_internodealigned_in_smp;
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index 5b1a315f77bc..f259dd834272 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -460,7 +460,7 @@ static unsigned long srcu_readers_unlock_idx(struct srcu_struct *ssp, int idx)
 
 		sum += atomic_long_read(&cpuc->srcu_unlock_count[idx]);
 		if (IS_ENABLED(CONFIG_PROVE_RCU))
-			mask = mask | READ_ONCE(cpuc->srcu_nmi_safety);
+			mask = mask | READ_ONCE(cpuc->srcu_reader_flavor);
 	}
 	WARN_ONCE(IS_ENABLED(CONFIG_PROVE_RCU) && (mask & (mask >> 1)),
 		  "Mixed NMI-safe readers for srcu_struct at %ps.\n", ssp);
@@ -699,25 +699,25 @@ EXPORT_SYMBOL_GPL(cleanup_srcu_struct);
 
 #ifdef CONFIG_PROVE_RCU
 /*
- * Check for consistent NMI safety.
+ * Check for consistent reader flavor.
  */
-void srcu_check_nmi_safety(struct srcu_struct *ssp, bool nmi_safe)
+void srcu_check_read_flavor(struct srcu_struct *ssp, int read_flavor)
 {
-	int nmi_safe_mask = 1 << nmi_safe;
-	int old_nmi_safe_mask;
+	int reader_flavor_mask = 1 << read_flavor;
+	int old_reader_flavor_mask;
 	struct srcu_data *sdp;
 
 	/* NMI-unsafe use in NMI is a bad sign */
-	WARN_ON_ONCE(!nmi_safe && in_nmi());
+	WARN_ON_ONCE(!read_flavor && in_nmi());
 	sdp = raw_cpu_ptr(ssp->sda);
-	old_nmi_safe_mask = READ_ONCE(sdp->srcu_nmi_safety);
-	if (!old_nmi_safe_mask) {
-		WRITE_ONCE(sdp->srcu_nmi_safety, nmi_safe_mask);
+	old_reader_flavor_mask = READ_ONCE(sdp->srcu_reader_flavor);
+	if (!old_reader_flavor_mask) {
+		WRITE_ONCE(sdp->srcu_reader_flavor, reader_flavor_mask);
 		return;
 	}
-	WARN_ONCE(old_nmi_safe_mask != nmi_safe_mask, "CPU %d old state %d new state %d\n", sdp->cpu, old_nmi_safe_mask, nmi_safe_mask);
+	WARN_ONCE(old_reader_flavor_mask != reader_flavor_mask, "CPU %d old state %d new state %d\n", sdp->cpu, old_reader_flavor_mask, reader_flavor_mask);
 }
-EXPORT_SYMBOL_GPL(srcu_check_nmi_safety);
+EXPORT_SYMBOL_GPL(srcu_check_read_flavor);
 #endif /* CONFIG_PROVE_RCU */
 
 /*
-- 
2.46.0


  parent reply	other threads:[~2024-11-12 14:52 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-11-12 14:51 [PATCH 00/16] SRCU for v6.13 Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 01/16] srcu: Replace WARN_ON_ONCE() with BUILD_BUG_ON() if possible Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 02/16] srcu: Rename srcu_might_be_idle() to srcu_should_expedite() Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 03/16] srcu: Introduce srcu_gp_is_expedited() helper function Frederic Weisbecker
2024-11-12 14:51 ` Frederic Weisbecker [this message]
2024-11-12 14:51 ` [PATCH 05/16] srcu: Bit manipulation changes for additional reader flavor Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 06/16] srcu: Standardize srcu_data pointers to "sdp" and similar Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 07/16] srcu: Improve srcu_read_lock{,_nmisafe}() comments Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 08/16] srcu: Create CPP macros for normal and NMI-safe SRCU readers Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 09/16] srcu: Add srcu_read_lock_lite() and srcu_read_unlock_lite() Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 10/16] srcu: Allow inlining of __srcu_read_{,un}lock_lite() Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 11/16] rcutorture: Expand RCUTORTURE_RDR_MASK_[12] to eight bits Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 12/16] rcutorture: Add reader_flavor parameter for SRCU readers Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 13/16] rcutorture: Add srcu_read_lock_lite() support to rcutorture.reader_flavor Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 14/16] rcutorture: Add light-weight SRCU scenario Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 15/16] refscale: Add srcu_read_lock_lite() support using "srcu-lite" Frederic Weisbecker
2024-11-12 14:51 ` [PATCH 16/16] srcu: Improve srcu_read_lock_lite() kernel-doc comment Frederic Weisbecker

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