diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2020-10-27 13:55:21 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-11-15 09:49:10 -0500 |
| commit | 28f1326710555bbe666f64452d08f2d7dd657cae (patch) | |
| tree | 0500d5c7ff66eda5051b0221b04c73b28c8d8942 /include/linux | |
| parent | e8dbf19508a112d125190df77ee0464b7ba56192 (diff) | |
eventfd: Export eventfd_ctx_do_read()
Where events are consumed in the kernel, for example by KVM's
irqfd_wakeup() and VFIO's virqfd_wakeup(), they currently lack a
mechanism to drain the eventfd's counter.
Since the wait queue is already locked while the wakeup functions are
invoked, all they really need to do is call eventfd_ctx_do_read().
Add a check for the lock, and export it for them.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20201027135523.646811-2-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/eventfd.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h index dc4fd8a6644d..fa0a524baed0 100644 --- a/include/linux/eventfd.h +++ b/include/linux/eventfd.h @@ -41,6 +41,7 @@ struct eventfd_ctx *eventfd_ctx_fileget(struct file *file); __u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n); int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait, __u64 *cnt); +void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt); DECLARE_PER_CPU(int, eventfd_wake_count); @@ -82,6 +83,11 @@ static inline bool eventfd_signal_count(void) return false; } +static inline void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt) +{ + +} + #endif #endif /* _LINUX_EVENTFD_H */ |