diff options
Diffstat (limited to 'kernel/cgroup.c')
| -rw-r--r-- | kernel/cgroup.c | 99 |
1 files changed, 89 insertions, 10 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 0f2d00519d37..41ee01e392e6 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1757,11 +1757,85 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen) } EXPORT_SYMBOL_GPL(cgroup_path); +/* + * Control Group taskset + */ struct task_and_cgroup { struct task_struct *task; struct cgroup *cgrp; }; +struct cgroup_taskset { + struct task_and_cgroup single; + struct flex_array *tc_array; + int tc_array_len; + int idx; + struct cgroup *cur_cgrp; +}; + +/** + * cgroup_taskset_first - reset taskset and return the first task + * @tset: taskset of interest + * + * @tset iteration is initialized and the first task is returned. + */ +struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset) +{ + if (tset->tc_array) { + tset->idx = 0; + return cgroup_taskset_next(tset); + } else { + tset->cur_cgrp = tset->single.cgrp; + return tset->single.task; + } +} +EXPORT_SYMBOL_GPL(cgroup_taskset_first); + +/** + * cgroup_taskset_next - iterate to the next task in taskset + * @tset: taskset of interest + * + * Return the next task in @tset. Iteration must have been initialized + * with cgroup_taskset_first(). + */ +struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset) +{ + struct task_and_cgroup *tc; + + if (!tset->tc_array || tset->idx >= tset->tc_array_len) + return NULL; + + tc = flex_array_get(tset->tc_array, tset->idx++); + tset->cur_cgrp = tc->cgrp; + return tc->task; +} +EXPORT_SYMBOL_GPL(cgroup_taskset_next); + +/** + * cgroup_taskset_cur_cgroup - return the matching cgroup for the current task + * @tset: taskset of interest + * + * Return the cgroup for the current (last returned) task of @tset. This + * function must be preceded by either cgroup_taskset_first() or + * cgroup_taskset_next(). + */ +struct cgroup *cgroup_taskset_cur_cgroup(struct cgroup_taskset *tset) +{ + return tset->cur_cgrp; +} +EXPORT_SYMBOL_GPL(cgroup_taskset_cur_cgroup); + +/** + * cgroup_taskset_size - return the number of tasks in taskset + * @tset: taskset of interest + */ +int cgroup_taskset_size(struct cgroup_taskset *tset) +{ + return tset->tc_array ? tset->tc_array_len : 1; +} +EXPORT_SYMBOL_GPL(cgroup_taskset_size); + + /* * cgroup_task_migrate - move a task from one cgroup to another. * @@ -1842,6 +1916,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) struct cgroup_subsys *ss, *failed_ss = NULL; struct cgroup *oldcgrp; struct cgroupfs_root *root = cgrp->root; + struct cgroup_taskset tset = { }; /* @tsk either already exited or can't exit until the end */ if (tsk->flags & PF_EXITING) @@ -1852,9 +1927,12 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) if (cgrp == oldcgrp) return 0; + tset.single.task = tsk; + tset.single.cgrp = oldcgrp; + for_each_subsys(root, ss) { if (ss->can_attach) { - retval = ss->can_attach(ss, cgrp, tsk); + retval = ss->can_attach(ss, cgrp, &tset); if (retval) { /* * Remember on which subsystem the can_attach() @@ -1885,7 +1963,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) if (ss->attach_task) ss->attach_task(cgrp, tsk); if (ss->attach) - ss->attach(ss, cgrp, oldcgrp, tsk); + ss->attach(ss, cgrp, &tset); } synchronize_rcu(); @@ -1907,7 +1985,7 @@ out: */ break; if (ss->cancel_attach) - ss->cancel_attach(ss, cgrp, tsk); + ss->cancel_attach(ss, cgrp, &tset); } } return retval; @@ -2023,6 +2101,7 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) struct task_struct *tsk; struct task_and_cgroup *tc; struct flex_array *group; + struct cgroup_taskset tset = { }; /* * we need to make sure we have css_sets for all the tasks we're * going to move -before- we actually start moving them, so that in @@ -2089,6 +2168,8 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) } while_each_thread(leader, tsk); /* remember the number of threads in the array for later. */ group_size = i; + tset.tc_array = group; + tset.tc_array_len = group_size; read_unlock(&tasklist_lock); /* methods shouldn't be called if no task is actually migrating */ @@ -2101,7 +2182,7 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) */ for_each_subsys(root, ss) { if (ss->can_attach) { - retval = ss->can_attach(ss, cgrp, leader); + retval = ss->can_attach(ss, cgrp, &tset); if (retval) { failed_ss = ss; goto out_cancel_attach; @@ -2183,10 +2264,8 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) * being moved, this call will need to be reworked to communicate that. */ for_each_subsys(root, ss) { - if (ss->attach) { - tc = flex_array_get(group, 0); - ss->attach(ss, cgrp, tc->cgrp, tc->task); - } + if (ss->attach) + ss->attach(ss, cgrp, &tset); } /* @@ -2208,11 +2287,11 @@ out_cancel_attach: for_each_subsys(root, ss) { if (ss == failed_ss) { if (cancel_failed_ss && ss->cancel_attach) - ss->cancel_attach(ss, cgrp, leader); + ss->cancel_attach(ss, cgrp, &tset); break; } if (ss->cancel_attach) - ss->cancel_attach(ss, cgrp, leader); + ss->cancel_attach(ss, cgrp, &tset); } } out_put_tasks: |