From bb9d97b6dffa10cec5e1ce9adbce60f3c2b5eabc Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 12 Dec 2011 18:12:21 -0800 Subject: cgroup: don't use subsys->can_attach_task() or ->attach_task() Now that subsys->can_attach() and attach() take @tset instead of @task, they can handle per-task operations. Convert ->can_attach_task() and ->attach_task() users to use ->can_attach() and attach() instead. Most converions are straight-forward. Noteworthy changes are, * In cgroup_freezer, remove unnecessary NULL assignments to unused methods. It's useless and very prone to get out of sync, which already happened. * In cpuset, PF_THREAD_BOUND test is checked for each task. This doesn't make any practical difference but is conceptually cleaner. Signed-off-by: Tejun Heo Reviewed-by: KAMEZAWA Hiroyuki Reviewed-by: Frederic Weisbecker Acked-by: Li Zefan Cc: Paul Menage Cc: Balbir Singh Cc: Daisuke Nishimura Cc: James Morris Cc: Ingo Molnar Cc: Peter Zijlstra --- block/blk-cgroup.c | 45 ++++++++++++++++++++++++++++----------------- 1 file changed, 28 insertions(+), 17 deletions(-) (limited to 'block') diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 8f630cec906e..b8c143d68ee0 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -30,8 +30,10 @@ EXPORT_SYMBOL_GPL(blkio_root_cgroup); static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *, struct cgroup *); -static int blkiocg_can_attach_task(struct cgroup *, struct task_struct *); -static void blkiocg_attach_task(struct cgroup *, struct task_struct *); +static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *, + struct cgroup_taskset *); +static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *, + struct cgroup_taskset *); static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *); static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *); @@ -44,8 +46,8 @@ static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *); struct cgroup_subsys blkio_subsys = { .name = "blkio", .create = blkiocg_create, - .can_attach_task = blkiocg_can_attach_task, - .attach_task = blkiocg_attach_task, + .can_attach = blkiocg_can_attach, + .attach = blkiocg_attach, .destroy = blkiocg_destroy, .populate = blkiocg_populate, #ifdef CONFIG_BLK_CGROUP @@ -1626,30 +1628,39 @@ done: * of the main cic data structures. For now we allow a task to change * its cgroup only if it's the only owner of its ioc. */ -static int blkiocg_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) +static int blkiocg_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, + struct cgroup_taskset *tset) { + struct task_struct *task; struct io_context *ioc; int ret = 0; /* task_lock() is needed to avoid races with exit_io_context() */ - task_lock(tsk); - ioc = tsk->io_context; - if (ioc && atomic_read(&ioc->nr_tasks) > 1) - ret = -EINVAL; - task_unlock(tsk); - + cgroup_taskset_for_each(task, cgrp, tset) { + task_lock(task); + ioc = task->io_context; + if (ioc && atomic_read(&ioc->nr_tasks) > 1) + ret = -EINVAL; + task_unlock(task); + if (ret) + break; + } return ret; } -static void blkiocg_attach_task(struct cgroup *cgrp, struct task_struct *tsk) +static void blkiocg_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, + struct cgroup_taskset *tset) { + struct task_struct *task; struct io_context *ioc; - task_lock(tsk); - ioc = tsk->io_context; - if (ioc) - ioc->cgroup_changed = 1; - task_unlock(tsk); + cgroup_taskset_for_each(task, cgrp, tset) { + task_lock(task); + ioc = task->io_context; + if (ioc) + ioc->cgroup_changed = 1; + task_unlock(task); + } } void blkio_policy_register(struct blkio_policy_type *blkiop) -- cgit v1.2.3-70-g09d2