lkml.org 
[lkml]   [2011]   [Nov]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 10/10] cgroup: kill subsys->can_attach_task(), pre_attach() and attach_task()
Date
These three methods are no longer used.  Kill them.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Paul Menage <paul@paulmenage.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
---
Documentation/cgroups/cgroups.txt | 20 --------------
include/linux/cgroup.h | 3 --
kernel/cgroup.c | 53 +++---------------------------------
3 files changed, 5 insertions(+), 71 deletions(-)

diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt
index bf5d6c9..eb1b609 100644
--- a/Documentation/cgroups/cgroups.txt
+++ b/Documentation/cgroups/cgroups.txt
@@ -615,13 +615,6 @@ 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);
-(cgroup_mutex held by caller)
-
-As can_attach, but for operations that must be run once per task to be
-attached (possibly many when using cgroup_attach_proc). Called after
-can_attach.
-
void cancel_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
struct cgroup_taskset *tset)
(cgroup_mutex held by caller)
@@ -632,12 +625,6 @@ function, so that the subsystem can implement a rollback. If not, not necessary.
This will be called only about subsystems whose can_attach() operation have
succeeded. The parameters are identical to can_attach().

-void pre_attach(struct cgroup *cgrp);
-(cgroup_mutex held by caller)
-
-For any non-per-thread attachment work that needs to happen before
-attach_task. Needed by cpuset.
-
void attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
struct cgroup_taskset *tset)
(cgroup_mutex held by caller)
@@ -646,13 +633,6 @@ Called after the task has been attached to the cgroup, to allow any
post-attachment activity that requires memory allocations or blocking.
The parameters are identical to can_attach().

-void attach_task(struct cgroup *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,
-like can_attach_task. Called before attach. Currently does not support any
-subsystem that might need the old_cgrp for every thread in the group.
-
void fork(struct cgroup_subsy *ss, struct task_struct *task)

Called when a task is forked into a cgroup.
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 2470c8e..5659d37 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -490,11 +490,8 @@ struct cgroup_subsys {
void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp);
int (*can_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,
struct cgroup_taskset *tset);
- int (*can_attach_task)(struct cgroup *cgrp, struct task_struct *tsk);
void (*cancel_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,
struct cgroup_taskset *tset);
- void (*pre_attach)(struct cgroup *cgrp);
- void (*attach_task)(struct cgroup *cgrp, struct task_struct *tsk);
void (*attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,
struct cgroup_taskset *tset);
void (*fork)(struct cgroup_subsys *ss, struct task_struct *task);
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 0bb7927..d2b3697 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1944,13 +1944,6 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
goto out;
}
}
- if (ss->can_attach_task) {
- retval = ss->can_attach_task(cgrp, tsk);
- if (retval) {
- failed_ss = ss;
- goto out;
- }
- }
}

retval = cgroup_task_migrate(cgrp, oldcgrp, tsk, false);
@@ -1958,10 +1951,6 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
goto out;

for_each_subsys(root, ss) {
- if (ss->pre_attach)
- ss->pre_attach(cgrp);
- if (ss->attach_task)
- ss->attach_task(cgrp, tsk);
if (ss->attach)
ss->attach(ss, cgrp, &tset);
}
@@ -2093,7 +2082,6 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
{
int retval, i, group_size, nr_migrating_tasks;
struct cgroup_subsys *ss, *failed_ss = NULL;
- bool cancel_failed_ss = false;
/* guaranteed to be initialized later, but the compiler needs this */
struct css_set *oldcg;
struct cgroupfs_root *root = cgrp->root;
@@ -2188,21 +2176,6 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
goto out_cancel_attach;
}
}
- /* a callback to be run on every thread in the threadgroup. */
- if (ss->can_attach_task) {
- /* run on each task in the threadgroup. */
- for (i = 0; i < group_size; i++) {
- tc = flex_array_get(group, i);
- if (tc->cgrp == cgrp)
- continue;
- retval = ss->can_attach_task(cgrp, tc->task);
- if (retval) {
- failed_ss = ss;
- cancel_failed_ss = true;
- goto out_cancel_attach;
- }
- }
- }
}

/*
@@ -2234,15 +2207,10 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
}

/*
- * step 3: now that we're guaranteed success wrt the css_sets, proceed
- * to move all tasks to the new cgroup, calling ss->attach_task for each
- * one along the way. there are no failure cases after here, so this is
- * the commit point.
+ * step 3: now that we're guaranteed success wrt the css_sets,
+ * proceed to move all tasks to the new cgroup. There are no
+ * failure cases after here, so this is the commit point.
*/
- for_each_subsys(root, ss) {
- if (ss->pre_attach)
- ss->pre_attach(cgrp);
- }
for (i = 0; i < group_size; i++) {
tc = flex_array_get(group, i);
/* leave current thread as it is if it's already there */
@@ -2251,19 +2219,11 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)

retval = cgroup_task_migrate(cgrp, tc->cgrp, tc->task, true);
BUG_ON(retval != 0);
-
- /* attach each task to each subsystem */
- for_each_subsys(root, ss) {
- if (ss->attach_task)
- ss->attach_task(cgrp, tc->task);
- }
}
/* nothing is sensitive to fork() after this point. */

/*
- * step 4: do expensive, non-thread-specific subsystem callbacks.
- * TODO: if ever a subsystem needs to know the oldcgrp for each task
- * being moved, this call will need to be reworked to communicate that.
+ * step 4: do subsystem attach callbacks.
*/
for_each_subsys(root, ss) {
if (ss->attach)
@@ -2287,11 +2247,8 @@ out_cancel_attach:
/* same deal as in cgroup_attach_task */
if (retval) {
for_each_subsys(root, ss) {
- if (ss == failed_ss) {
- if (cancel_failed_ss && ss->cancel_attach)
- ss->cancel_attach(ss, cgrp, &tset);
+ if (ss == failed_ss)
break;
- }
if (ss->cancel_attach)
ss->cancel_attach(ss, cgrp, &tset);
}
--
1.7.3.1


\
 
 \ /
  Last update: 2011-11-02 00:51    [W:0.200 / U:4.276 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site