3.16.39-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Zefan Li <[email protected]> commit 06f4e94898918bcad00cdd4d349313a439d6911e upstream. A new task inherits cpus_allowed and mems_allowed masks from its parent, but if someone changes cpuset's config by writing to cpuset.cpus/cpuset.mems before this new task is inserted into the cgroup's task list, the new task won't be updated accordingly. Signed-off-by: Zefan Li <[email protected]> Signed-off-by: Tejun Heo <[email protected]> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <[email protected]> --- kernel/cpuset.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1963,6 +1963,20 @@ static void cpuset_css_free(struct cgrou kfree(cs); } +/* + * Make sure the new task conform to the current state of its parent, + * which could have been changed by cpuset just after it inherits the + * state from the parent and before it sits on the cgroup's task list. + */ +void cpuset_fork(struct task_struct *task) +{ + if (task_css_is_root(task, cpuset_cgrp_id)) + return; + + set_cpus_allowed_ptr(task, ¤t->cpus_allowed); + task->mems_allowed = current->mems_allowed; +} + struct cgroup_subsys cpuset_cgrp_subsys = { .css_alloc = cpuset_css_alloc, .css_online = cpuset_css_online, @@ -1971,6 +1985,7 @@ struct cgroup_subsys cpuset_cgrp_subsys .can_attach = cpuset_can_attach, .cancel_attach = cpuset_cancel_attach, .attach = cpuset_attach, + .fork = cpuset_fork, .base_cftypes = files, .early_init = 1, };
