From aa1ea0ccb030a6a765cc7b0808213ddc80a03a4d Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 5 Oct 2011 11:43:46 +1100 Subject: [PATCH] cgroups: add previous cgroup in can_attach_task/attach_task callbacks This is to prepare the integration of a new max number of proc cgroup subsystem. We'll need to release some resources from the previous cgroup. Signed-off-by: Frederic Weisbecker Acked-by: Paul Menage Cc: Li Zefan Cc: Johannes Weiner Cc: Aditya Kali Cc: Oleg Nesterov Cc: Kay Sievers Cc: Tim Hockin Cc: Tejun Heo Acked-by: Kirill A. Shutemov Signed-off-by: Andrew Morton --- Documentation/cgroups/cgroups.txt | 6 ++++-- block/blk-cgroup.c | 12 ++++++++---- include/linux/cgroup.h | 6 ++++-- kernel/cgroup.c | 11 +++++++---- kernel/cgroup_freezer.c | 3 ++- kernel/cpuset.c | 6 ++++-- kernel/events/core.c | 5 +++-- kernel/sched.c | 6 ++++-- 8 files changed, 36 insertions(+), 19 deletions(-) diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 9c452ef2328c..f5a0e9111d49 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -605,7 +605,8 @@ called on a fork. If this method returns 0 (success) then this should remain valid while the caller holds cgroup_mutex and it is ensured that either attach() or cancel_attach() will be called in future. -int can_attach_task(struct cgroup *cgrp, struct task_struct *tsk); +int can_attach_task(struct cgroup *cgrp, struct cgroup *old_cgrp, + struct task_struct *tsk); (cgroup_mutex held by caller) As can_attach, but for operations that must be run once per task to be @@ -635,7 +636,8 @@ void attach(struct cgroup_subsys *ss, struct cgroup *cgrp, Called after the task has been attached to the cgroup, to allow any post-attachment activity that requires memory allocations or blocking. -void attach_task(struct cgroup *cgrp, struct task_struct *tsk); +void attach_task(struct cgroup *cgrp, struct cgroup *old_cgrp, + struct task_struct *tsk); (cgroup_mutex held by caller) As attach, but for operations that must be run once per task to be attached, diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index b596e54ddd71..c8ec781bb268 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_task(struct cgroup *, struct cgroup *, + struct task_struct *); +static void blkiocg_attach_task(struct cgroup *, struct cgroup *, + struct task_struct *); static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *); static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *); @@ -1609,7 +1611,8 @@ 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_task(struct cgroup *cgrp, struct cgroup *old_cgrp, + struct task_struct *tsk) { struct io_context *ioc; int ret = 0; @@ -1624,7 +1627,8 @@ static int blkiocg_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) return ret; } -static void blkiocg_attach_task(struct cgroup *cgrp, struct task_struct *tsk) +static void blkiocg_attach_task(struct cgroup *cgrp, struct cgroup *old_cgrp, + struct task_struct *tsk) { struct io_context *ioc; diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index da7e4bc34e8c..ed34eb8ca43c 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -468,11 +468,13 @@ struct cgroup_subsys { void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp); int (*can_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp, struct task_struct *tsk); - int (*can_attach_task)(struct cgroup *cgrp, struct task_struct *tsk); + int (*can_attach_task)(struct cgroup *cgrp, struct cgroup *old_cgrp, + struct task_struct *tsk); void (*cancel_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp, struct task_struct *tsk); void (*pre_attach)(struct cgroup *cgrp); - void (*attach_task)(struct cgroup *cgrp, struct task_struct *tsk); + void (*attach_task)(struct cgroup *cgrp, struct cgroup *old_cgrp, + struct task_struct *tsk); void (*attach)(struct cgroup_subsys *ss, struct cgroup *cgrp, struct cgroup *old_cgrp, struct task_struct *tsk); void (*fork)(struct cgroup_subsys *ss, struct task_struct *task); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 8386b21224ef..90b508d36674 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1844,7 +1844,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) } } if (ss->can_attach_task) { - retval = ss->can_attach_task(cgrp, tsk); + retval = ss->can_attach_task(cgrp, oldcgrp, tsk); if (retval) { failed_ss = ss; goto out; @@ -1860,7 +1860,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) if (ss->pre_attach) ss->pre_attach(cgrp); if (ss->attach_task) - ss->attach_task(cgrp, tsk); + ss->attach_task(cgrp, oldcgrp, tsk); if (ss->attach) ss->attach(ss, cgrp, oldcgrp, tsk); } @@ -2075,7 +2075,10 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) /* run on each task in the threadgroup. */ for (i = 0; i < group_size; i++) { tsk = flex_array_get_ptr(group, i); - retval = ss->can_attach_task(cgrp, tsk); + oldcgrp = task_cgroup_from_root(tsk, root); + + retval = ss->can_attach_task(cgrp, + oldcgrp, tsk); if (retval) { failed_ss = ss; cancel_failed_ss = true; @@ -2141,7 +2144,7 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) /* attach each task to each subsystem */ for_each_subsys(root, ss) { if (ss->attach_task) - ss->attach_task(cgrp, tsk); + ss->attach_task(cgrp, oldcgrp, tsk); } } else { BUG_ON(retval != -ESRCH); diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index 5e828a2ca8e6..ee34627c4408 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -175,7 +175,8 @@ static int freezer_can_attach(struct cgroup_subsys *ss, return 0; } -static int freezer_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) +static int freezer_can_attach_task(struct cgroup *cgrp, struct cgroup *old_cgrp, + struct task_struct *tsk) { rcu_read_lock(); if (__cgroup_freezing_or_frozen(tsk)) { diff --git a/kernel/cpuset.c b/kernel/cpuset.c index d970fb508e34..9ec7cc79e6e8 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1390,7 +1390,8 @@ static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont, return 0; } -static int cpuset_can_attach_task(struct cgroup *cgrp, struct task_struct *task) +static int cpuset_can_attach_task(struct cgroup *cgrp, struct cgroup *old_cgrp, + struct task_struct *task) { return security_task_setscheduler(task); } @@ -1418,7 +1419,8 @@ static void cpuset_pre_attach(struct cgroup *cont) } /* Per-thread attachment work. */ -static void cpuset_attach_task(struct cgroup *cont, struct task_struct *tsk) +static void cpuset_attach_task(struct cgroup *cont, struct cgroup *old, + struct task_struct *tsk) { int err; struct cpuset *cs = cgroup_cs(cont); diff --git a/kernel/events/core.c b/kernel/events/core.c index 69e5b4064b97..3e8b1c9710b0 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7138,7 +7138,8 @@ static int __perf_cgroup_move(void *info) } static void -perf_cgroup_attach_task(struct cgroup *cgrp, struct task_struct *task) +perf_cgroup_attach_task(struct cgroup *cgrp, struct cgroup *old_cgrp, + struct task_struct *task) { task_function_call(task, __perf_cgroup_move, task); } @@ -7154,7 +7155,7 @@ static void perf_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp, if (!(task->flags & PF_EXITING)) return; - perf_cgroup_attach_task(cgrp, task); + perf_cgroup_attach_task(cgrp, old_cgrp, task); } struct cgroup_subsys perf_subsys = { diff --git a/kernel/sched.c b/kernel/sched.c index 6c8cb8addb16..4c61617eb962 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -9128,7 +9128,8 @@ cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) } static int -cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) +cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct cgroup *old_cgrp, + struct task_struct *tsk) { #ifdef CONFIG_RT_GROUP_SCHED if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) @@ -9142,7 +9143,8 @@ cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) } static void -cpu_cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) +cpu_cgroup_attach_task(struct cgroup *cgrp, struct cgroup *old_cgrp, + struct task_struct *tsk) { sched_move_task(tsk); } -- 2.39.5