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authorMarcel Ziswiler <marcel.ziswiler@toradex.com>2019-12-18 22:52:20 +0100
committerMarcel Ziswiler <marcel.ziswiler@toradex.com>2019-12-18 22:52:20 +0100
commit1ddf624b0b268fdc0b80b1de618b98f8d117afea (patch)
tree3d3218332bcb34cb0afa01d6ad996058a3dbcb77 /include/linux/cgroup.h
parent6b774eec1f9d3064e9b33634dfa99d5666d0a73a (diff)
parentbfb9e5c03076a446b1f4f6a523ddc8d723c907a6 (diff)
Merge tag 'v4.14.159' into 4.14-2.0.x-imx
This is the 4.14.159 stable release Conflicts: arch/arm/Kconfig.debug arch/arm/boot/dts/imx7s.dtsi arch/arm/mach-imx/cpuidle-imx6sx.c drivers/crypto/caam/caamalg.c drivers/crypto/mxs-dcp.c drivers/dma/imx-sdma.c drivers/input/keyboard/imx_keypad.c drivers/net/can/flexcan.c drivers/net/can/rx-offload.c drivers/net/wireless/ath/ath10k/pci.c drivers/pci/dwc/pci-imx6.c drivers/spi/spi-fsl-lpspi.c drivers/usb/dwc3/gadget.c
Diffstat (limited to 'include/linux/cgroup.h')
-rw-r--r--include/linux/cgroup.h14
1 files changed, 12 insertions, 2 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 8e83c9055ccb..0e21619f1c03 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -42,6 +42,9 @@
/* walk all threaded css_sets in the domain */
#define CSS_TASK_ITER_THREADED (1U << 1)
+/* internal flags */
+#define CSS_TASK_ITER_SKIPPED (1U << 16)
+
/* a css_task_iter should be treated as an opaque object */
struct css_task_iter {
struct cgroup_subsys *ss;
@@ -56,6 +59,7 @@ struct css_task_iter {
struct list_head *task_pos;
struct list_head *tasks_head;
struct list_head *mg_tasks_head;
+ struct list_head *dying_tasks_head;
struct css_set *cur_cset;
struct css_set *cur_dcset;
@@ -484,7 +488,7 @@ 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)
@@ -494,7 +498,13 @@ 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();
}