[PATCH 06/13] proc: convert /proc/self to _print_integer()

[Alexey Dobriyan]

Benchmark readlink("/proc/self") 2^23 times:

        8.205992458 seconds time elapsed ( +-  0.15% )
        7.535168869 seconds time elapsed ( +-  0.09% )

        -8.2%

Signed-off-by: Alexey Dobriyan <adobri...@gmail.com>
---
 fs/proc/self.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/proc/self.c b/fs/proc/self.c
index 127265e5c55f..b2279412237b 100644
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -14,6 +14,7 @@ static const char *proc_self_get_link(struct dentry *dentry,
 {
        struct pid_namespace *ns = proc_pid_ns(inode);
        pid_t tgid = task_tgid_nr_ns(current, ns);
+       char buf[10], *p = buf + sizeof(buf);
        char *name;
 
        if (!tgid)
@@ -22,7 +23,11 @@ static const char *proc_self_get_link(struct dentry *dentry,
        name = kmalloc(10 + 1, dentry ? GFP_KERNEL : GFP_ATOMIC);
        if (unlikely(!name))
                return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
-       sprintf(name, "%u", tgid);
+
+       p = _print_integer_u32(p, tgid);
+       memcpy(name, p, buf + sizeof(buf) - p);
+       name[buf + sizeof(buf) - p] = '\0';
+
        set_delayed_call(done, kfree_link, name);
        return name;
 }
-- 
2.16.4