linux-kernel - [PATCH 5/5] lib/nodemask: inline next_node_in() and node

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Message-Id: <20220711044711.466822-6-yury.norov@gmail.com>
Date:   Sun, 10 Jul 2022 21:47:11 -0700
From:   Yury Norov <yury.norov@...il.com>
To:     linux-kernel@...r.kernel.org,
        Alexander Lobakin <alexandr.lobakin@...el.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Arnd Bergmann <arnd@...db.de>, David Gow <davidgow@...gle.com>,
        Eric Dumazet <edumazet@...gle.com>,
        Isabella Basso <isabbasso@...eup.net>,
        Kees Cook <keescook@...omium.org>,
        Keith Busch <kbusch@...nel.org>,
        Kumar Kartikeya Dwivedi <memxor@...il.com>,
        Marco Elver <elver@...gle.com>,
        Mark Rutland <mark.rutland@....com>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        Steven Rostedt <rostedt@...dmis.org>,
        Toke Høiland-Jørgensen <toke@...hat.com>
Cc:     Yury Norov <yury.norov@...il.com>
Subject: [PATCH 5/5] lib/nodemask: inline next_node_in() and node_random()

The functions are pretty thin wrappers around find_bit engine, and
keeping them in c-file prevents compiler from small_const_nbits()
optimization, which must take place for all systems with MAX_NUMNODES
less than BITS_PER_LONG (default is 16 for me).

Moving them in header file doesn't blow up the kernel size:
add/remove: 1/2 grow/shrink: 9/5 up/down: 968/-88 (880)

Signed-off-by: Yury Norov <yury.norov@...il.com>
---
 MAINTAINERS              |  1 -
 include/linux/nodemask.h | 27 ++++++++++++++++++++++-----
 lib/Makefile             |  2 +-
 lib/nodemask.c           | 30 ------------------------------
 4 files changed, 23 insertions(+), 37 deletions(-)
 delete mode 100644 lib/nodemask.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 7c0b8f28aa25..19c8d0ef1177 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3540,7 +3540,6 @@ F:	lib/bitmap.c
 F:	lib/cpumask.c
 F:	lib/find_bit.c
 F:	lib/find_bit_benchmark.c
-F:	lib/nodemask.c
 F:	lib/test_bitmap.c
 F:	tools/include/linux/bitmap.h
 F:	tools/include/linux/find.h
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 0f233b76c9ce..48ebe4007955 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -94,6 +94,7 @@
 #include <linux/bitmap.h>
 #include <linux/minmax.h>
 #include <linux/numa.h>
+#include <linux/random.h>
 
 typedef struct { DECLARE_BITMAP(bits, MAX_NUMNODES); } nodemask_t;
 extern nodemask_t _unused_nodemask_arg_;
@@ -276,7 +277,14 @@ static inline unsigned int __next_node(int n, const nodemask_t *srcp)
  * the first node in src if needed.  Returns MAX_NUMNODES if src is empty.
  */
 #define next_node_in(n, src) __next_node_in((n), &(src))
-unsigned int __next_node_in(int node, const nodemask_t *srcp);
+static inline unsigned int __next_node_in(int node, const nodemask_t *srcp)
+{
+	unsigned int ret = __next_node(node, srcp);
+
+	if (ret == MAX_NUMNODES)
+		ret = __first_node(srcp);
+	return ret;
+}
 
 static inline void init_nodemask_of_node(nodemask_t *mask, int node)
 {
@@ -493,14 +501,23 @@ static inline int num_node_state(enum node_states state)
 
 #endif
 
+/*
+ * Return the bit number of a random bit set in the nodemask.
+ * (returns NUMA_NO_NODE if nodemask is empty)
+ */
+static inline int node_random(const nodemask_t *maskp)
+{
 #if defined(CONFIG_NUMA) && (MAX_NUMNODES > 1)
-extern int node_random(const nodemask_t *maskp);
+	int w, bit = NUMA_NO_NODE;
+
+	w = nodes_weight(*maskp);
+	if (w)
+		bit = find_nth_bit(maskp->bits, MAX_NUMNODES, get_random_int() % w);
+	return bit;
 #else
-static inline int node_random(const nodemask_t *mask)
-{
 	return 0;
-}
 #endif
+}
 
 #define node_online_map 	node_states[N_ONLINE]
 #define node_possible_map 	node_states[N_POSSIBLE]
diff --git a/lib/Makefile b/lib/Makefile
index f99bf61f8bbc..731cea0342d1 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -33,7 +33,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
 	 flex_proportions.o ratelimit.o show_mem.o \
 	 is_single_threaded.o plist.o decompress.o kobject_uevent.o \
 	 earlycpio.o seq_buf.o siphash.o dec_and_lock.o \
-	 nmi_backtrace.o nodemask.o win_minmax.o memcat_p.o \
+	 nmi_backtrace.o win_minmax.o memcat_p.o \
 	 buildid.o
 
 lib-$(CONFIG_PRINTK) += dump_stack.o
diff --git a/lib/nodemask.c b/lib/nodemask.c
deleted file mode 100644
index 7dad4ce8ff59..000000000000
--- a/lib/nodemask.c
+++ /dev/null
@@ -1,30 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include <linux/nodemask.h>
-#include <linux/module.h>
-#include <linux/random.h>
-
-unsigned int __next_node_in(int node, const nodemask_t *srcp)
-{
-	unsigned int ret = __next_node(node, srcp);
-
-	if (ret == MAX_NUMNODES)
-		ret = __first_node(srcp);
-	return ret;
-}
-EXPORT_SYMBOL(__next_node_in);
-
-#ifdef CONFIG_NUMA
-/*
- * Return the bit number of a random bit set in the nodemask.
- * (returns NUMA_NO_NODE if nodemask is empty)
- */
-int node_random(const nodemask_t *maskp)
-{
-	int w, bit = NUMA_NO_NODE;
-
-	w = nodes_weight(*maskp);
-	if (w)
-		bit = find_nth_bit(maskp->bits, MAX_NUMNODES, get_random_int() % w);
-	return bit;
-}
-#endif
-- 
2.34.1