diff options
| author |   Thomas Gleixner <tglx@linutronix.de> | 2021-03-09 09:42:06 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2021-03-17 16:33:52 +0100 |
| commit | ca5f625118955fc544c3cb3dee7055d33ecadafb (patch) | |
| tree | 49314867119ecf8952eb9a06d0a0ee220b708ff9 /include/linux/interrupt.h | |
| parent | tasklets: Use static inlines for stub implementations (diff) | |
| download | wireguard-linux-ca5f625118955fc544c3cb3dee7055d33ecadafb.tar.xz wireguard-linux-ca5f625118955fc544c3cb3dee7055d33ecadafb.zip | |
tasklets: Provide tasklet_disable_in_atomic()
Replacing the spin wait loops in tasklet_unlock_wait() with
wait_var_event() is not possible as a handful of tasklet_disable()
invocations are happening in atomic context. All other invocations are in
teardown paths which can sleep.
Provide tasklet_disable_in_atomic() and tasklet_unlock_spin_wait() to
convert the few atomic use cases over, which allows to change
tasklet_disable() and tasklet_unlock_wait() in a later step.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309084241.563164193@linutronix.de
Diffstat (limited to 'include/linux/interrupt.h')
| -rw-r--r-- | include/linux/interrupt.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 0a4ce25c1464..3c8a29176258 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -675,10 +675,21 @@ static inline void tasklet_unlock_wait(struct tasklet_struct *t) while (test_bit(TASKLET_STATE_RUN, &t->state)) cpu_relax(); } + +/* + * Do not use in new code. Waiting for tasklets from atomic contexts is + * error prone and should be avoided. + */ +static inline void tasklet_unlock_spin_wait(struct tasklet_struct *t) +{ + while (test_bit(TASKLET_STATE_RUN, &t->state)) + cpu_relax(); +} #else static inline int tasklet_trylock(struct tasklet_struct *t) { return 1; } static inline void tasklet_unlock(struct tasklet_struct *t) { } static inline void tasklet_unlock_wait(struct tasklet_struct *t) { } +static inline void tasklet_unlock_spin_wait(struct tasklet_struct *t) { } #endif extern void __tasklet_schedule(struct tasklet_struct *t); @@ -703,6 +714,17 @@ static inline void tasklet_disable_nosync(struct tasklet_struct *t) smp_mb__after_atomic(); } +/* + * Do not use in new code. Disabling tasklets from atomic contexts is + * error prone and should be avoided. + */ +static inline void tasklet_disable_in_atomic(struct tasklet_struct *t) +{ + tasklet_disable_nosync(t); + tasklet_unlock_spin_wait(t); + smp_mb(); +} + static inline void tasklet_disable(struct tasklet_struct *t) { tasklet_disable_nosync(t); |