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| author | Tejun Heo <tj@kernel.org> | 2017-05-15 15:34:01 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2017-07-21 17:14:51 +0200 |
| commit | bc2fb7ed089ffd16d26e1d95b898a37d2b37d201 (patch) | |
| tree | 87675b436609b0a31ffde08798c761876e6c4db0 /kernel/cgroup/cgroup-v1.c | |
| parent | cgroup: reorganize cgroup.procs / task write path (diff) | |
| download | linux-bc2fb7ed089ffd16d26e1d95b898a37d2b37d201.tar.xz linux-bc2fb7ed089ffd16d26e1d95b898a37d2b37d201.zip | |
cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS
css_task_iter currently always walks all tasks. With the scheduled
cgroup v2 thread support, the iterator would need to handle multiple
types of iteration. As a preparation, add @flags to
css_task_iter_start() and implement CSS_TASK_ITER_PROCS. If the flag
is not specified, it walks all tasks as before. When asserted, the
iterator only walks the group leaders.
For now, the only user of the flag is cgroup v2 "cgroup.procs" file
which no longer needs to skip non-leader tasks in cgroup_procs_next().
Note that cgroup v1 "cgroup.procs" can't use the group leader walk as
v1 "cgroup.procs" doesn't mean "list all thread group leaders in the
cgroup" but "list all thread group id's with any threads in the
cgroup".
While at it, update cgroup_procs_show() to use task_pid_vnr() instead
of task_tgid_vnr(). As the iteration guarantees that the function
only sees group leaders, this doesn't change the output and will allow
sharing the function for thread iteration.
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/cgroup/cgroup-v1.c')
| -rw-r--r-- | kernel/cgroup/cgroup-v1.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index 60f72475863e..167aaab04bf9 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -121,7 +121,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) * ->can_attach() fails. */ do { - css_task_iter_start(&from->self, &it); + css_task_iter_start(&from->self, 0, &it); task = css_task_iter_next(&it); if (task) get_task_struct(task); @@ -373,7 +373,7 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type, if (!array) return -ENOMEM; /* now, populate the array */ - css_task_iter_start(&cgrp->self, &it); + css_task_iter_start(&cgrp->self, 0, &it); while ((tsk = css_task_iter_next(&it))) { if (unlikely(n == length)) break; @@ -749,7 +749,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry) } rcu_read_unlock(); - css_task_iter_start(&cgrp->self, &it); + css_task_iter_start(&cgrp->self, 0, &it); while ((tsk = css_task_iter_next(&it))) { switch (tsk->state) { case TASK_RUNNING: |