[PATCH 09/13] proc: convert dentry flushing on exit to _print_integer()

[Alexey Dobriyan]

Benchmark fork+exit+waitpid 2^16 times:

        6.579161299 seconds time elapsed ( +-  0.24% )
        6.482729157 seconds time elapsed ( +-  0.42% )

        -1.5%

Dentry flushing is very small part of exit(2), effects should be more
visible on a tiny 1-page process which doesn't uses libc.

Signed-off-by: Alexey Dobriyan <adobri...@gmail.com>
---
 fs/proc/base.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 17666bd61ac8..79d2f7d72ad1 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -3022,11 +3022,11 @@ static const struct inode_operations 
proc_tgid_base_inode_operations = {
 static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
 {
        struct dentry *dentry, *leader, *dir;
-       char buf[10 + 1];
+       char buf[10];
        struct qstr name;
 
-       name.name = buf;
-       name.len = snprintf(buf, sizeof(buf), "%u", pid);
+       name.name = _print_integer_u32(buf + sizeof(buf), pid);
+       name.len = buf + sizeof(buf) - (char *)name.name;
        /* no ->d_hash() rejects on procfs */
        dentry = d_hash_and_lookup(mnt->mnt_root, &name);
        if (dentry) {
@@ -3037,8 +3037,8 @@ static void proc_flush_task_mnt(struct vfsmount *mnt, 
pid_t pid, pid_t tgid)
        if (pid == tgid)
                return;
 
-       name.name = buf;
-       name.len = snprintf(buf, sizeof(buf), "%u", tgid);
+       name.name = _print_integer_u32(buf + sizeof(buf), tgid);
+       name.len = buf + sizeof(buf) - (char *)name.name;
        leader = d_hash_and_lookup(mnt->mnt_root, &name);
        if (!leader)
                goto out;
@@ -3049,8 +3049,8 @@ static void proc_flush_task_mnt(struct vfsmount *mnt, 
pid_t pid, pid_t tgid)
        if (!dir)
                goto out_put_leader;
 
-       name.name = buf;
-       name.len = snprintf(buf, sizeof(buf), "%u", pid);
+       name.name = _print_integer_u32(buf + sizeof(buf), pid);
+       name.len = buf + sizeof(buf) - (char *)name.name;
        dentry = d_hash_and_lookup(dir, &name);
        if (dentry) {
                d_invalidate(dentry);
-- 
2.16.4