diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2021-08-15 23:28:11 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2021-08-17 17:21:09 +0200 |
| commit | 456cfbc65cd072f4f53936ee5a37eb1447a7d3ba (patch) | |
| tree | b567f3f01eebfe206b5f355d5f9941a38fbee88c /kernel/locking/rtmutex_common.h | |
| parent | 7980aa397cc0968ea3ffee7a985c31c92ad84f81 (diff) | |
locking/rtmutex: Prepare RT rt_mutex_wake_q for RT locks
Add an rtlock_task pointer to rt_mutex_wake_q, which allows to handle the RT
specific wakeup for spin/rwlock waiters. The pointer is just consuming 4/8
bytes on the stack so it is provided unconditionaly to avoid #ifdeffery all
over the place.
This cannot use a regular wake_q, because a task can have concurrent wakeups which
would make it miss either lock or the regular wakeups, depending on what gets
queued first, unless task struct gains a separate wake_q_node for this, which
would be overkill, because there can only be a single task which gets woken
up in the spin/rw_lock unlock path.
No functional change for non-RT enabled kernels.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211303.253614678@linutronix.de
Diffstat (limited to 'kernel/locking/rtmutex_common.h')
| -rw-r--r-- | kernel/locking/rtmutex_common.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h index ff36316003d8..424ee0f5e5a4 100644 --- a/kernel/locking/rtmutex_common.h +++ b/kernel/locking/rtmutex_common.h @@ -42,15 +42,18 @@ struct rt_mutex_waiter { /** * rt_wake_q_head - Wrapper around regular wake_q_head to support * "sleeping" spinlocks on RT - * @head: The regular wake_q_head for sleeping lock variants + * @head: The regular wake_q_head for sleeping lock variants + * @rtlock_task: Task pointer for RT lock (spin/rwlock) wakeups */ struct rt_wake_q_head { struct wake_q_head head; + struct task_struct *rtlock_task; }; #define DEFINE_RT_WAKE_Q(name) \ struct rt_wake_q_head name = { \ .head = WAKE_Q_HEAD_INITIALIZER(name.head), \ + .rtlock_task = NULL, \ } /* |