diff options
| author | Andrei Vagin <avagin@google.com> | 2023-03-07 23:31:58 -0800 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2023-07-17 16:08:08 -0700 |
| commit | 6f63904c8f3edb65bd85c1be01d69214ff8ca4c5 (patch) | |
| tree | 1411084a185f099140b25f05f0bbfd7104abf702 /include | |
| parent | ab83f455f04df5b2f7c6d4de03b6d2eaeaa27b8a (diff) | |
sched: add a few helpers to wake up tasks on the current cpu
Add complete_on_current_cpu, wake_up_poll_on_current_cpu helpers to wake
up tasks on the current CPU.
These two helpers are useful when the task needs to make a synchronous context
switch to another task. In this context, synchronous means it wakes up the
target task and falls asleep right after that.
One example of such workloads is seccomp user notifies. This mechanism allows
the supervisor process handles system calls on behalf of a target process.
While the supervisor is handling an intercepted system call, the target process
will be blocked in the kernel, waiting for a response to come back.
On-CPU context switches are much faster than regular ones.
Signed-off-by: Andrei Vagin <avagin@google.com>
Acked-by: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230308073201.3102738-4-avagin@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/completion.h | 1 | ||||
| -rw-r--r-- | include/linux/swait.h | 2 | ||||
| -rw-r--r-- | include/linux/wait.h | 3 |
3 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/completion.h b/include/linux/completion.h index 62b32b19e0a8..fb2915676574 100644 --- a/include/linux/completion.h +++ b/include/linux/completion.h @@ -116,6 +116,7 @@ extern bool try_wait_for_completion(struct completion *x); extern bool completion_done(struct completion *x); extern void complete(struct completion *); +extern void complete_on_current_cpu(struct completion *x); extern void complete_all(struct completion *); #endif diff --git a/include/linux/swait.h b/include/linux/swait.h index 6a8c22b8c2a5..d324419482a0 100644 --- a/include/linux/swait.h +++ b/include/linux/swait.h @@ -146,7 +146,7 @@ static inline bool swq_has_sleeper(struct swait_queue_head *wq) extern void swake_up_one(struct swait_queue_head *q); extern void swake_up_all(struct swait_queue_head *q); -extern void swake_up_locked(struct swait_queue_head *q); +extern void swake_up_locked(struct swait_queue_head *q, int wake_flags); extern void prepare_to_swait_exclusive(struct swait_queue_head *q, struct swait_queue *wait, int state); extern long prepare_to_swait_event(struct swait_queue_head *q, struct swait_queue *wait, int state); diff --git a/include/linux/wait.h b/include/linux/wait.h index a0307b516b09..5ec7739400f4 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -210,6 +210,7 @@ __remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq } int __wake_up(struct wait_queue_head *wq_head, unsigned int mode, int nr, void *key); +void __wake_up_on_current_cpu(struct wait_queue_head *wq_head, unsigned int mode, void *key); void __wake_up_locked_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); void __wake_up_locked_key_bookmark(struct wait_queue_head *wq_head, unsigned int mode, void *key, wait_queue_entry_t *bookmark); @@ -237,6 +238,8 @@ void __wake_up_pollfree(struct wait_queue_head *wq_head); #define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m)) #define wake_up_poll(x, m) \ __wake_up(x, TASK_NORMAL, 1, poll_to_key(m)) +#define wake_up_poll_on_current_cpu(x, m) \ + __wake_up_on_current_cpu(x, TASK_NORMAL, poll_to_key(m)) #define wake_up_locked_poll(x, m) \ __wake_up_locked_key((x), TASK_NORMAL, poll_to_key(m)) #define wake_up_interruptible_poll(x, m) \ |