Messages in this thread | | | From | Wander Lairson Costa <> | Subject | [PATCH v2 0/4] Fix put_task_struct() calls under PREEMPT_RT | Date | Fri, 20 Jan 2023 12:02:38 -0300 |
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put_task_struct() decrements a usage counter and calls __put_task_struct() if the counter reaches zero.
__put_task_struct() indirectly acquires a spinlock, which is a sleeping lock under PREEMPT_RT. Therefore, we can't call put_task_struct() in an atomic context in RT kernels.
This patch series introduces put_task_struct_atomic_safe(), which defers the call to __put_task_struct() to a process context when compiled with PREEMPT_RT.
It also fixes known problematic call sites.
Changelog: ==========
v2: * Add the put_task_struct_atomic_safe() function that is responsible for handling the conditions to call put_task_struct(). * Replace put_task_struct() by put_task_struct_atomic_safe() in known atomic call sites.
Wander Lairson Costa (4): sched/task: Add the put_task_struct_atomic_safe function sched/deadline: fix inactive_task_timer splat sched/rt: use put_task_struct_atomic_safe() to avoid potential splat sched/core: use put_task_struct_atomic_safe() to avoid potential splat
include/linux/sched/task.h | 21 +++++++++++++++++++++ kernel/fork.c | 8 ++++++++ kernel/sched/core.c | 2 +- kernel/sched/deadline.c | 2 +- kernel/sched/rt.c | 4 ++-- 5 files changed, 33 insertions(+), 4 deletions(-)
-- 2.39.0
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