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| author | Otavio Salvador <otavio@ossystems.com.br> | 2020-05-20 08:43:03 -0300 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2020-05-20 08:43:03 -0300 |
| commit | 1279cd128bba968ebe0a2df7f7ae38bae90250ef (patch) | |
| tree | df6b1a190760f51465122ca4c13492d5ac5984c6 /include/linux/cgroup.h | |
| parent | 0a8ab17689e628c84a666195bfc6ab85d11cf057 (diff) | |
| parent | 2ae782ca839e0ee07de37122ddea362adff2e975 (diff) | |
Merge pull request #76 from toradex/4.9-2.3.x-imx
4.9 2.3.x imx
Diffstat (limited to 'include/linux/cgroup.h')
| -rw-r--r-- | include/linux/cgroup.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 7620a8bc0493..8be03520995c 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -462,7 +462,7 @@ static inline struct cgroup_subsys_state *task_css(struct task_struct *task, * * Find the css for the (@task, @subsys_id) combination, increment a * reference on and return it. This function is guaranteed to return a - * valid css. + * valid css. The returned css may already have been offlined. */ static inline struct cgroup_subsys_state * task_get_css(struct task_struct *task, int subsys_id) @@ -472,7 +472,13 @@ task_get_css(struct task_struct *task, int subsys_id) rcu_read_lock(); while (true) { css = task_css(task, subsys_id); - if (likely(css_tryget_online(css))) + /* + * Can't use css_tryget_online() here. A task which has + * PF_EXITING set may stay associated with an offline css. + * If such task calls this function, css_tryget_online() + * will keep failing. + */ + if (likely(css_tryget(css))) break; cpu_relax(); } |