Benchmark pread /proc/1/task/1/children 2^21 times on the same system: 6.766400479 s 4.328648442
-36% (need to remeasure on a controlled set of children) Signed-off-by: Alexey Dobriyan <adobri...@gmail.com> --- fs/proc/array.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/proc/array.c b/fs/proc/array.c index d0565527166a..045ce2cac1dd 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -710,9 +710,11 @@ get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos) static int children_seq_show(struct seq_file *seq, void *v) { struct inode *inode = file_inode(seq->file); + char buf[10 + 1], *p = buf + sizeof(buf); - seq_printf(seq, "%d ", pid_nr_ns(v, proc_pid_ns(inode))); - return 0; + *--p = ' '; + p = _print_integer_u32(p, pid_nr_ns(v, proc_pid_ns(inode))); + return seq_write(seq, p, buf + sizeof(buf) - p); } static void *children_seq_start(struct seq_file *seq, loff_t *pos) -- 2.16.4