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Subject[PATCH 06/13] proc: convert /proc/self to _print_integer()
Date
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 <adobriyan@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
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