[PATCH 2/4] proc: change first_tid() to use while_each_thread() rather than next_thread()

Oleg Nesterov
2013-11-20T18:29:10Z

Rerwrite the main loop to use while_each_thread() instead of
next_thread(). We are going to fix or replace while_each_thread(),
next_thread() should be avoided whenever possible.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
fs/proc/base.c | 20 ++++++++++----------
1 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index da12c5c..7ab3785 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -3100,23 +3100,23 @@ static struct task_struct *first_tid(struct task_struct *leader,
}

/* If nr exceeds the number of threads there is nothing todo */
- pos = NULL;
if (nr && nr >= get_nr_threads(leader))
- goto out;
+ goto fail;
/* It could be unhashed before we take rcu lock */
if (!pid_alive(leader))
- goto out;
+ goto fail;

/* If we haven't found our starting place yet start
* with the leader and walk nr threads forward.
*/
- for (pos = leader; nr > 0; --nr) {
- pos = next_thread(pos);
- if (pos == leader) {
- pos = NULL;
- goto out;
- }
- }
+ pos = leader;
+ do {
+ if (nr-- <= 0)
+ goto found;
+ } while_each_thread(leader, pos);
+fail:
+ pos = NULL;
+ goto out;
found:
get_task_struct(pos);
out:
--
1.5.5.1