diff options
| author | Tejun Heo <tj@kernel.org> | 2014-11-18 02:49:51 -0500 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2014-11-18 02:49:51 -0500 |
| commit | 56c807ba4e91f0980567b6a69de239677879b17f (patch) | |
| tree | 509bdb009fdd4cbc87c75b2138e07600afc357ac | |
| parent | 7d172cc89b8589e4173d0c73a1ddaae408f29c9d (diff) | |
cgroup: add cgroup_subsys->css_e_css_changed()
Add a new cgroup_subsys operatoin ->css_e_css_changed(). This is
invoked if any of the effective csses seen from the css's cgroup may
have changed. This will be used to implement cgroup writeback
support.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Zefan Li <lizefan@huawei.com>
| -rw-r--r-- | include/linux/cgroup.h | 1 | ||||
| -rw-r--r-- | kernel/cgroup.c | 18 |
2 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index e717a39f22ea..3a04aeb8b5a1 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -615,6 +615,7 @@ struct cgroup_subsys { void (*css_released)(struct cgroup_subsys_state *css); void (*css_free)(struct cgroup_subsys_state *css); void (*css_reset)(struct cgroup_subsys_state *css); + void (*css_e_css_changed)(struct cgroup_subsys_state *css); int (*can_attach)(struct cgroup_subsys_state *css, struct cgroup_taskset *tset); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index c8558693102b..69f033582a1a 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2836,6 +2836,24 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, } } + /* + * The effective csses of all the descendants (excluding @cgrp) may + * have changed. Subsystems can optionally subscribe to this event + * by implementing ->css_e_css_changed() which is invoked if any of + * the effective csses seen from the css's cgroup may have changed. + */ + for_each_subsys(ss, ssid) { + struct cgroup_subsys_state *this_css = cgroup_css(cgrp, ss); + struct cgroup_subsys_state *css; + + if (!ss->css_e_css_changed || !this_css) + continue; + + css_for_each_descendant_pre(css, this_css) + if (css != this_css) + ss->css_e_css_changed(css); + } + kernfs_activate(cgrp->kn); ret = 0; out_unlock: |