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| author | Christian Brauner <brauner@kernel.org> | 2026-09-10 17:48:09 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2026-10-05 13:11:49 +0200 |
| commit | 5d075bd77ffbced7863d31e22cb2e7107e1ab957 (patch) | |
| tree | 38f5725d6ba552c45ef444091cd3088ace975c3c /include | |
| parent | c2fe52e23c12aef43c0522196c28f9e2721634ae (diff) | |
| download | linux-next-5d075bd77ffbced7863d31e22cb2e7107e1ab957.tar.gz linux-next-5d075bd77ffbced7863d31e22cb2e7107e1ab957.zip | |
sched: add wait_var_event_state()
All wait_var_event() sleep in a fixed task state. For coredumps we need
a variant that takes the state from the caller the way
wait_event_state() does. This allows us to continue sleeping with
TASK_FREEZABLE. That's certainly also a useful addition for other places.
Link: https://patch.msgid.link/20260910-work-coredump-unlock-self-v4-11-a5c1800dc930@kernel.org
Reviewed-by: NeilBrown <neil@brown.name>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/wait_bit.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/wait_bit.h b/include/linux/wait_bit.h index 553d7b23e3ad..af077ed4caf6 100644 --- a/include/linux/wait_bit.h +++ b/include/linux/wait_bit.h @@ -433,6 +433,32 @@ do { \ }) /** + * wait_var_event_state - wait for a variable to be updated and notified + * @var: the address of variable being waited on + * @condition: the condition to wait for + * @state: the task state to sleep in, %TASK_UNINTERRUPTIBLE etc. + * + * Wait for a @condition to be true, only re-checking when a wake up is + * received for the given @var (an arbitrary kernel address which need + * not be directly related to the given condition, but usually is). + * + * Returns 0 if the condition became true, or %-ERESTARTSYS if a signal + * arrived which @state allows to interrupt. + * + * The condition should normally use smp_load_acquire() or a similarly + * ordered access to ensure that any changes to memory made before the + * condition became true will be visible after the wait completes. + */ +#define wait_var_event_state(var, condition, state) \ +({ \ + int __ret = 0; \ + might_sleep(); \ + if (!(condition)) \ + __ret = ___wait_var_event(var, condition, (state), 0, 0, schedule()); \ + __ret; \ +}) + +/** * wait_var_event_any_lock - wait for a variable to be updated under a lock * @var: the address of the variable being waited on * @condition: condition to wait for |