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authorDario Faggioli <raistlin@linux.it>2010-11-30 19:51:33 +0100
committerIngo Molnar <mingo@elte.hu>2010-12-08 20:16:00 +0100
commit806c09a7db457be3758e14b1f152761135d89af5 (patch)
treeb0fafff45634be80f3caf7227c5d47317f26e0e9
parent8e9255e6a2141e050d51bc4d96dbef494a87d653 (diff)
sched: Make pushable_tasks CONFIG_SMP dependant
As noted by Peter Zijlstra at https://lkml.org/lkml/2010/11/10/391 (while reviewing other stuff, though), tracking pushable tasks only makes sense on SMP systems. Signed-off-by: Dario Faggioli <raistlin@linux.it> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1291143093.2697.298.camel@Palantir> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--include/linux/init_task.h9
-rw-r--r--include/linux/sched.h2
-rw-r--r--kernel/sched.c2
3 files changed, 12 insertions, 1 deletions
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 1f8c06ce0fa6..6ed8812bfe2d 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -12,6 +12,13 @@
#include <linux/securebits.h>
#include <net/net_namespace.h>
+#ifdef CONFIG_SMP
+# define INIT_PUSHABLE_TASKS(tsk) \
+ .pushable_tasks = PLIST_NODE_INIT(tsk.pushable_tasks, MAX_PRIO),
+#else
+# define INIT_PUSHABLE_TASKS(tsk)
+#endif
+
extern struct files_struct init_files;
extern struct fs_struct init_fs;
@@ -137,7 +144,7 @@ extern struct cred init_cred;
.nr_cpus_allowed = NR_CPUS, \
}, \
.tasks = LIST_HEAD_INIT(tsk.tasks), \
- .pushable_tasks = PLIST_NODE_INIT(tsk.pushable_tasks, MAX_PRIO), \
+ INIT_PUSHABLE_TASKS(tsk) \
.ptraced = LIST_HEAD_INIT(tsk.ptraced), \
.ptrace_entry = LIST_HEAD_INIT(tsk.ptrace_entry), \
.real_parent = &tsk, \
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 9c2d46da486e..4f92a239c14d 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1240,7 +1240,9 @@ struct task_struct {
#endif
struct list_head tasks;
+#ifdef CONFIG_SMP
struct plist_node pushable_tasks;
+#endif
struct mm_struct *mm, *active_mm;
#if defined(SPLIT_RSS_COUNTING)
diff --git a/kernel/sched.c b/kernel/sched.c
index b646dad4a40e..3925a1bbf5dd 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2595,7 +2595,9 @@ void sched_fork(struct task_struct *p, int clone_flags)
/* Want to start with kernel preemption disabled. */
task_thread_info(p)->preempt_count = 1;
#endif
+#ifdef CONFIG_SMP
plist_node_init(&p->pushable_tasks, MAX_PRIO);
+#endif
put_cpu();
}