sched: add fair-user scheduler
Enable user-id based fair group scheduling. This is useful for anyone
who wants to test the group scheduler w/o having to enable
CONFIG_CGROUPS.
A separate scheduling group (i.e struct task_grp) is automatically created for
every new user added to the system. Upon uid change for a task, it is made to
move to the corresponding scheduling group.
A /proc tunable (/proc/root_user_share) is also provided to tune root
user's quota of cpu bandwidth.
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/sched.c b/kernel/sched.c
index e10c403..f33608e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -200,7 +200,12 @@
.cfs_rq = init_cfs_rq_p,
};
+#ifdef CONFIG_FAIR_USER_SCHED
+#define INIT_TASK_GRP_LOAD 2*NICE_0_LOAD
+#else
#define INIT_TASK_GRP_LOAD NICE_0_LOAD
+#endif
+
static int init_task_grp_load = INIT_TASK_GRP_LOAD;
/* return group to which a task belongs */
@@ -208,7 +213,11 @@
{
struct task_grp *tg;
+#ifdef CONFIG_FAIR_USER_SCHED
+ tg = p->user->tg;
+#else
tg = &init_task_grp;
+#endif
return tg;
}
