From 1c99315bb36b5d776210546d438ca928dc9b1f22 Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@redhat.com>
Date: Thu, 9 Apr 2009 09:50:36 -0600
Subject: [PATCH] kthread: move sched-realeted initialization from kthreadd
context
kthreadd is the single thread which implements ths "create" request, move
sched_setscheduler/etc from create_kthread() to kthread_create() to
improve the scalability.
We should be careful with sched_setscheduler(), use _nochek helper.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Vitaliy Gusev <vgusev@openvz.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
kernel/kthread.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/kernel/kthread.c b/kernel/kthread.c
index c013bf000ce67..4ebaf8519abf6 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -97,19 +97,10 @@ static void create_kthread(struct kthread_create_info *create)
/* We want our own signal handler (we take no signals by default). */
pid = kernel_thread(kthread, create, CLONE_FS | CLONE_FILES | SIGCHLD);
- if (pid < 0) {
+ if (pid < 0)
create->result = ERR_PTR(pid);
- } else {
- struct sched_param param = { .sched_priority = 0 };
+ else
wait_for_completion(&create->started);
- /*
- * root may have changed our (kthreadd's) priority or CPU mask.
- * The kernel thread should not inherit these properties.
- */
- sched_setscheduler(create->result, SCHED_NORMAL, ¶m);
- set_user_nice(create->result, KTHREAD_NICE_LEVEL);
- set_cpus_allowed_ptr(create->result, cpu_all_mask);
- }
complete(&create->done);
}
@@ -152,11 +143,20 @@ struct task_struct *kthread_create(int (*threadfn)(void *data),
wait_for_completion(&create.done);
if (!IS_ERR(create.result)) {
+ struct sched_param param = { .sched_priority = 0 };
va_list args;
+
va_start(args, namefmt);
vsnprintf(create.result->comm, sizeof(create.result->comm),
namefmt, args);
va_end(args);
+ /*
+ * root may have changed our (kthreadd's) priority or CPU mask.
+ * The kernel thread should not inherit these properties.
+ */
+ sched_setscheduler_nocheck(create.result, SCHED_NORMAL, ¶m);
+ set_user_nice(create.result, KTHREAD_NICE_LEVEL);
+ set_cpus_allowed_ptr(create.result, cpu_all_mask);
}
return create.result;
}
--
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