From 8e65b5649a761f0ff399bf09f40df3dc45941a43 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 8 Dec 2011 15:42:35 +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/core.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 8f630cec906e..fda00810a6d4 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 *); @@ -1626,7 +1628,8 @@ 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; @@ -1641,7 +1644,8 @@ 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 1b7f9d525013..0731c6bf96c7 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 d9d5648f3cdc..ba8f3ebeb046 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 fcb93fca782d..43e76144b01c 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -181,7 +181,8 @@ 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) { return cgroup_freezing(tsk) ? -EBUSY : 0; } diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 793eca605d5c..163b16ed81e3 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1404,7 +1404,8 @@ 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); } @@ -1432,7 +1433,8 @@ 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 2f8f3f103cb4..4eafb1b9f9f8 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6938,7 +6938,8 @@ 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); } @@ -6954,7 +6955,7 @@ 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/core.c b/kernel/sched/core.c index e1aa1f994bdf..cdd11484d94f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7531,7 +7531,8 @@ 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) { /* * kthreadd can fork workers for an RT workqueue in a cgroup @@ -7554,7 +7555,8 @@ 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); } -- 2.39.2