From: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Date: Sat, 17 Sep 2005 02:27:40 +0000 (-0700)
Subject: [PATCH] CPU hotplug breaks wake_up_new_task
X-Git-Tag: v2.6.14-rc2~5^2~50
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=26ff6ad9786abf6f40a6d3cbb89753b4fa50cb00;p=~shefty%2Frdma-dev.git

[PATCH] CPU hotplug breaks wake_up_new_task

Fix a problem wherein a new-born task is added to a dead CPU.

Signed-off-by: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Acked-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/kernel/fork.c b/kernel/fork.c
index 8149f360288..533ce27f4b2 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1062,7 +1062,8 @@ static task_t *copy_process(unsigned long clone_flags,
 	 * parent's CPU). This avoids alot of nasty races.
 	 */
 	p->cpus_allowed = current->cpus_allowed;
-	if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed)))
+	if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) ||
+			!cpu_online(task_cpu(p))))
 		set_task_cpu(p, smp_processor_id());
 
 	/*