lkml.org 
[lkml]   [2016]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.4 048/118] cpuset: make sure new tasks conform to the current config of the cpuset
    Date
    4.4-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Zefan Li <lizefan@huawei.com>

    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 <lizefan@huawei.com>
    Signed-off-by: Tejun Heo <tj@kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    kernel/cpuset.c | 15 +++++++++++++++
    1 file changed, 15 insertions(+)

    --- a/kernel/cpuset.c
    +++ b/kernel/cpuset.c
    @@ -2074,6 +2074,20 @@ static void cpuset_bind(struct cgroup_su
    mutex_unlock(&cpuset_mutex);
    }

    +/*
    + * 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, &current->cpus_allowed);
    + task->mems_allowed = current->mems_allowed;
    +}
    +
    struct cgroup_subsys cpuset_cgrp_subsys = {
    .css_alloc = cpuset_css_alloc,
    .css_online = cpuset_css_online,
    @@ -2084,6 +2098,7 @@ struct cgroup_subsys cpuset_cgrp_subsys
    .attach = cpuset_attach,
    .post_attach = cpuset_post_attach,
    .bind = cpuset_bind,
    + .fork = cpuset_fork,
    .legacy_cftypes = files,
    .early_init = 1,
    };

    \
     
     \ /
      Last update: 2016-09-23 00:04    [W:2.737 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site