sched: clean up some control group code

- replace "cont" with "cgrp" in a few places in the CFS cgroup code, 
- use write_uint rather than write for cpu.shares write function

Signed-off-by: Paul Menage <menage@google.com>
Acked-by : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 18 insertions, 35 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index d1e6663d3ab..cc9cd5b710a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -7124,25 +7124,25 @@ unsigned long sched_group_shares(struct task_group *tg)
 #ifdef CONFIG_FAIR_CGROUP_SCHED
 
 /* return corresponding task_group object of a cgroup */
-static inline struct task_group *cgroup_tg(struct cgroup *cont)
+static inline struct task_group *cgroup_tg(struct cgroup *cgrp)
 {
-        return container_of(cgroup_subsys_state(cont, cpu_cgroup_subsys_id),
-                                         struct task_group, css);
+        return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id),
+                            struct task_group, css);
 }
 
 static struct cgroup_subsys_state *
-cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
+cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp)
 {
         struct task_group *tg;
 
-        if (!cont->parent) {
+        if (!cgrp->parent) {
                 /* This is early initialization for the top cgroup */
-                init_task_group.css.cgroup = cont;
+                init_task_group.css.cgroup = cgrp;
                 return &init_task_group.css;
         }
 
         /* we support only 1-level deep hierarchical scheduler atm */
-        if (cont->parent->parent)
+        if (cgrp->parent->parent)
                 return ERR_PTR(-EINVAL);
 
         tg = sched_create_group();
@@ -7150,21 +7150,21 @@ cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
                 return ERR_PTR(-ENOMEM);
 
         /* Bind the cgroup to task_group object we just created */
-        tg->css.cgroup = cont;
+        tg->css.cgroup = cgrp;
 
         return &tg->css;
 }
 
 static void cpu_cgroup_destroy(struct cgroup_subsys *ss,
-                                        struct cgroup *cont)
+                               struct cgroup *cgrp)
 {
-        struct task_group *tg = cgroup_tg(cont);
+        struct task_group *tg = cgroup_tg(cgrp);
 
         sched_destroy_group(tg);
 }
 
 static int cpu_cgroup_can_attach(struct cgroup_subsys *ss,
-                             struct cgroup *cont, struct task_struct *tsk)
+                             struct cgroup *cgrp, struct task_struct *tsk)
 {
         /* We don't support RT-tasks being in separate groups */
         if (tsk->sched_class != &fair_sched_class)
@@ -7174,38 +7174,21 @@ static int cpu_cgroup_can_attach(struct cgroup_subsys *ss,
 }
 
 static void
-cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cont,
+cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
                         struct cgroup *old_cont, struct task_struct *tsk)
 {
         sched_move_task(tsk);
 }
 
-static ssize_t cpu_shares_write(struct cgroup *cont, struct cftype *cftype,
-                                struct file *file, const char __user *userbuf,
-                                size_t nbytes, loff_t *ppos)
+static int cpu_shares_write_uint(struct cgroup *cgrp, struct cftype *cftype,
+                                u64 shareval)
 {
-        unsigned long shareval;
-        struct task_group *tg = cgroup_tg(cont);
-        char buffer[2*sizeof(unsigned long) + 1];
-        int rc;
-
-        if (nbytes > 2*sizeof(unsigned long))   /* safety check */
-                return -E2BIG;
-
-        if (copy_from_user(buffer, userbuf, nbytes))
-                return -EFAULT;
-
-        buffer[nbytes] = 0;     /* nul-terminate */
-        shareval = simple_strtoul(buffer, NULL, 10);
-
-        rc = sched_group_set_shares(tg, shareval);
-
-        return (rc < 0 ? rc : nbytes);
+        return sched_group_set_shares(cgroup_tg(cgrp), shareval);
 }
 
-static u64 cpu_shares_read_uint(struct cgroup *cont, struct cftype *cft)
+static u64 cpu_shares_read_uint(struct cgroup *cgrp, struct cftype *cft)
 {
-        struct task_group *tg = cgroup_tg(cont);
+        struct task_group *tg = cgroup_tg(cgrp);
 
         return (u64) tg->shares;
 }
@@ -7213,7 +7196,7 @@ static u64 cpu_shares_read_uint(struct cgroup *cont, struct cftype *cft)
 static struct cftype cpu_shares = {
         .name = "shares",
         .read_uint = cpu_shares_read_uint,
-        .write = cpu_shares_write,
+        .write_uint = cpu_shares_write_uint,
 };
 
 static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont)