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From: Christian Brauner <[email protected]>
To: [email protected]
Cc: Christoph Hellwig <[email protected]>, Jan Kara <[email protected]>,
	 Vitaly Kuznetsov <[email protected]>,
	 Sean Christopherson <[email protected]>,
	 Paolo Bonzini <[email protected]>,
	Thomas Gleixner <[email protected]>,
	 Ingo Molnar <[email protected]>, Borislav Petkov <[email protected]>,
	 Dave Hansen <[email protected]>,
	[email protected],  David Woodhouse <[email protected]>,
	Paul Durrant <[email protected]>,  Oded Gabbay <[email protected]>,
	Wu Hao <[email protected]>,  Tom Rix <[email protected]>,
	Moritz Fischer <[email protected]>,  Xu Yilun <[email protected]>,
	Zhenyu Wang <[email protected]>,
	 Zhi Wang <[email protected]>,
	Jani Nikula <[email protected]>,
	 Joonas Lahtinen <[email protected]>,
	 Rodrigo Vivi <[email protected]>,
	 Tvrtko Ursulin <[email protected]>,
	 David Airlie <[email protected]>,
	Daniel Vetter <[email protected]>,
	 Leon Romanovsky <[email protected]>,
	Jason Gunthorpe <[email protected]>,
	 Frederic Barrat <[email protected]>,
	 Andrew Donnellan <[email protected]>,
	Arnd Bergmann <[email protected]>,
	 Greg Kroah-Hartman <[email protected]>,
	 Eric Farman <[email protected]>,
	Matthew Rosato <[email protected]>,
	 Halil Pasic <[email protected]>,
	Vineeth Vijayan <[email protected]>,
	 Peter Oberparleiter <[email protected]>,
	 Heiko Carstens <[email protected]>,
	Vasily Gorbik <[email protected]>,
	 Alexander Gordeev <[email protected]>,
	 Christian Borntraeger <[email protected]>,
	 Sven Schnelle <[email protected]>,
	Tony Krowiak <[email protected]>,
	 Jason Herne <[email protected]>,
	 Harald Freudenberger <[email protected]>,
	 "Michael S. Tsirkin" <[email protected]>,
	Jason Wang <[email protected]>,
	 Xuan Zhuo <[email protected]>,
	 Diana Craciun <[email protected]>,
	 Alex Williamson <[email protected]>,
	 Eric Auger <[email protected]>, Fei Li <[email protected]>,
	 Benjamin LaHaise <[email protected]>,
	Christian Brauner <[email protected]>,
	 Johannes Weiner <[email protected]>,
	Michal Hocko <[email protected]>,
	 Roman Gushchin <[email protected]>,
	 Shakeel Butt <[email protected]>,
	Muchun Song <[email protected]>,
	 Kirti Wankhede <[email protected]>,
	[email protected],  [email protected],
	[email protected],  [email protected],
	[email protected],
	 [email protected], [email protected],
	 [email protected], [email protected],
	 [email protected],
	[email protected],
	 [email protected], [email protected],
	[email protected],  [email protected],
	Jens Axboe <[email protected]>,
	 Pavel Begunkov <[email protected]>,
	[email protected]
Subject: [PATCH v2 4/4] eventfd: make eventfd_signal{_mask}() void
Date: Wed, 22 Nov 2023 13:48:25 +0100	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

No caller care about the return value.

Signed-off-by: Christian Brauner <[email protected]>
---
 fs/eventfd.c            | 40 +++++++++++++++-------------------------
 include/linux/eventfd.h | 16 +++++++---------
 2 files changed, 22 insertions(+), 34 deletions(-)

diff --git a/fs/eventfd.c b/fs/eventfd.c
index a9a6de920fb4..13be2fb7fc96 100644
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -43,10 +43,19 @@ struct eventfd_ctx {
 	int id;
 };
 
-__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
+/**
+ * eventfd_signal - Adds @n to the eventfd counter.
+ * @ctx: [in] Pointer to the eventfd context.
+ * @mask: [in] poll mask
+ *
+ * This function is supposed to be called by the kernel in paths that do not
+ * allow sleeping. In this function we allow the counter to reach the ULLONG_MAX
+ * value, and we signal this as overflow condition by returning a EPOLLERR
+ * to poll(2).
+ */
+void eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
 {
 	unsigned long flags;
-	__u64 n = 1;
 
 	/*
 	 * Deadlock or stack overflow issues can happen if we recurse here
@@ -57,37 +66,18 @@ __u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
 	 * safe context.
 	 */
 	if (WARN_ON_ONCE(current->in_eventfd))
-		return 0;
+		return;
 
 	spin_lock_irqsave(&ctx->wqh.lock, flags);
 	current->in_eventfd = 1;
-	if (ULLONG_MAX - ctx->count < n)
-		n = ULLONG_MAX - ctx->count;
-	ctx->count += n;
+	if (ctx->count < ULLONG_MAX)
+		ctx->count++;
 	if (waitqueue_active(&ctx->wqh))
 		wake_up_locked_poll(&ctx->wqh, EPOLLIN | mask);
 	current->in_eventfd = 0;
 	spin_unlock_irqrestore(&ctx->wqh.lock, flags);
-
-	return n == 1;
-}
-
-/**
- * eventfd_signal - Adds @n to the eventfd counter.
- * @ctx: [in] Pointer to the eventfd context.
- *
- * This function is supposed to be called by the kernel in paths that do not
- * allow sleeping. In this function we allow the counter to reach the ULLONG_MAX
- * value, and we signal this as overflow condition by returning a EPOLLERR
- * to poll(2).
- *
- * Returns the amount by which the counter was incremented.
- */
-__u64 eventfd_signal(struct eventfd_ctx *ctx)
-{
-	return eventfd_signal_mask(ctx, 0);
 }
-EXPORT_SYMBOL_GPL(eventfd_signal);
+EXPORT_SYMBOL_GPL(eventfd_signal_mask);
 
 static void eventfd_free_ctx(struct eventfd_ctx *ctx)
 {
diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h
index 4f8aac7eb62a..fea7c4eb01d6 100644
--- a/include/linux/eventfd.h
+++ b/include/linux/eventfd.h
@@ -35,8 +35,7 @@ void eventfd_ctx_put(struct eventfd_ctx *ctx);
 struct file *eventfd_fget(int fd);
 struct eventfd_ctx *eventfd_ctx_fdget(int fd);
 struct eventfd_ctx *eventfd_ctx_fileget(struct file *file);
-__u64 eventfd_signal(struct eventfd_ctx *ctx);
-__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask);
+void eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask);
 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);
@@ -58,14 +57,8 @@ static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd)
 	return ERR_PTR(-ENOSYS);
 }
 
-static inline int eventfd_signal(struct eventfd_ctx *ctx)
+static inline void eventfd_signal_mask(struct eventfd_ctx *ctx, unsigned mask)
 {
-	return -ENOSYS;
-}
-
-static inline int eventfd_signal_mask(struct eventfd_ctx *ctx, unsigned mask)
-{
-	return -ENOSYS;
 }
 
 static inline void eventfd_ctx_put(struct eventfd_ctx *ctx)
@@ -91,5 +84,10 @@ static inline void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt)
 
 #endif
 
+static inline void eventfd_signal(struct eventfd_ctx *ctx)
+{
+	eventfd_signal_mask(ctx, 0);
+}
+
 #endif /* _LINUX_EVENTFD_H */
 

-- 
2.42.0


  parent reply	other threads:[~2023-11-22 12:50 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-22 12:48 [PATCH v2 0/4] eventfd: simplify signal helpers Christian Brauner
2023-11-22 12:48 ` [PATCH v2 1/4] i915: make inject_virtual_interrupt() void Christian Brauner
2023-11-22 15:05   ` Jan Kara
2023-11-23  0:24   ` Zhenyu Wang
2023-11-23 13:11     ` Christian Brauner
2023-11-22 12:48 ` [PATCH v2 2/4] eventfd: simplify eventfd_signal() Christian Brauner
2023-11-22 14:49   ` Xu Yilun
2023-11-22 15:05   ` Jan Kara
2023-11-22 15:19   ` Jani Nikula
2023-11-23 13:18     ` Christian Brauner
2023-11-24  2:02   ` Andrew Donnellan
2023-11-27 16:17   ` Eric Farman
2024-02-06 19:44   ` Stefan Hajnoczi
2024-02-07 14:33     ` Anthony Krowiak
2024-02-07 14:34   ` Paolo Bonzini
2024-02-08  9:02     ` Christian Brauner
2023-11-22 12:48 ` [PATCH v2 3/4] eventfd: simplify eventfd_signal_mask() Christian Brauner
2023-11-22 15:05   ` Jan Kara
2023-11-22 12:48 ` Christian Brauner [this message]
2023-11-22 15:06   ` [PATCH v2 4/4] eventfd: make eventfd_signal{_mask}() void Jan Kara
2023-11-23 19:43 ` [PATCH v2 0/4] eventfd: simplify signal helpers Jens Axboe
2023-11-24  7:47 ` Christian Brauner

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