[PATCH 1/2] proc: uninline name_to_int()

[PATCH 1/2] proc: uninline name_to_int()

[Alexey Dobriyan]

Save ~360 bytes.

	add/remove: 1/0 grow/shrink: 0/4 up/down: 104/-463 (-359)
	function                                     old     new   delta
	name_to_int                                    -     104    +104
	proc_pid_lookup                              217     126     -91
	proc_lookupfd_common                         212     121     -91
	proc_task_lookup                             289     194     -95
	__proc_create                                588     402    -186

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

 fs/proc/Makefile   |    1 +
 fs/proc/internal.h |   23 +----------------------
 fs/proc/util.c     |   23 +++++++++++++++++++++++
 3 files changed, 25 insertions(+), 22 deletions(-)

--- a/fs/proc/Makefile
+++ b/fs/proc/Makefile
@@ -20,6 +20,7 @@ proc-y	+= loadavg.o
 proc-y	+= meminfo.o
 proc-y	+= stat.o
 proc-y	+= uptime.o
+proc-y	+= util.o
 proc-y	+= version.o
 proc-y	+= softirqs.o
 proc-y	+= namespaces.o
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -103,28 +103,7 @@ static inline struct task_struct *get_proc_task(struct inode *inode)
 void task_dump_owner(struct task_struct *task, mode_t mode,
 		     kuid_t *ruid, kgid_t *rgid);
 
-static inline unsigned name_to_int(const struct qstr *qstr)
-{
-	const char *name = qstr->name;
-	int len = qstr->len;
-	unsigned n = 0;
-
-	if (len > 1 && *name == '0')
-		goto out;
-	while (len-- > 0) {
-		unsigned c = *name++ - '0';
-		if (c > 9)
-			goto out;
-		if (n >= (~0U-9)/10)
-			goto out;
-		n *= 10;
-		n += c;
-	}
-	return n;
-out:
-	return ~0U;
-}
-
+unsigned name_to_int(const struct qstr *qstr);
 /*
  * Offset of the first process in the /proc root directory..
  */
--- /dev/null
+++ b/fs/proc/util.c
@@ -0,0 +1,23 @@
+#include <linux/dcache.h>
+
+unsigned name_to_int(const struct qstr *qstr)
+{
+	const char *name = qstr->name;
+	int len = qstr->len;
+	unsigned n = 0;
+
+	if (len > 1 && *name == '0')
+		goto out;
+	while (len-- > 0) {
+		unsigned c = *name++ - '0';
+		if (c > 9)
+			goto out;
+		if (n >= (~0U-9)/10)
+			goto out;
+		n *= 10;
+		n += c;
+	}
+	return n;
+out:
+	return ~0U;
+}

[PATCH 2/2] proc: use do-while in name_to_int()

[Alexey Dobriyan]

Gcc doesn't know that "len" is guaranteed to be >=1 by dcache and
generates standard while-loop prologue duplicating loop condition.

	add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-27 (-27)
	function                                     old     new   delta
	name_to_int                                  104      77     -27


Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

 fs/proc/util.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/proc/util.c
+++ b/fs/proc/util.c
@@ -8,7 +8,7 @@ unsigned name_to_int(const struct qstr *qstr)
 
 	if (len > 1 && *name == '0')
 		goto out;
-	while (len-- > 0) {
+	do {
 		unsigned c = *name++ - '0';
 		if (c > 9)
 			goto out;
@@ -16,7 +16,7 @@ unsigned name_to_int(const struct qstr *qstr)
 			goto out;
 		n *= 10;
 		n += c;
-	}
+	} while (--len > 0);
 	return n;
 out:
 	return ~0U;