From: Yajun Deng <yajun.deng@linux.dev>
To: will@kernel.org, peterz@infradead.org, boqun.feng@gmail.com
Cc: linux-kernel@vger.kernel.org, Yajun Deng <yajun.deng@linux.dev>
Subject: [PATCH] refcount: introduce refcount_is_one() helper function
Date: Thu, 18 Nov 2021 11:53:28 +0800 [thread overview]
Message-ID: <20211118035328.5730-1-yajun.deng@linux.dev> (raw)
There are many cases where it is necessary to determine if refcount is one,
introduce refcount_is_one() helper function for these cases.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
---
include/linux/refcount.h | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/include/linux/refcount.h b/include/linux/refcount.h
index b8a6e387f8f9..1cc23c0e7454 100644
--- a/include/linux/refcount.h
+++ b/include/linux/refcount.h
@@ -147,6 +147,11 @@ static inline unsigned int refcount_read(const refcount_t *r)
return atomic_read(&r->refs);
}
+static inline bool refcount_is_one(const refcount_t *r)
+{
+ return refcount_read(r) == 1;
+}
+
static inline __must_check bool __refcount_add_not_zero(int i, refcount_t *r, int *oldp)
{
int old = refcount_read(r);
--
2.32.0
next reply other threads:[~2021-11-18 3:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-18 3:53 Yajun Deng [this message]
2021-11-18 7:42 ` [PATCH] refcount: introduce refcount_is_one() helper function Peter Zijlstra
2021-11-18 8:12 ` yajun.deng
2021-11-18 8:44 ` Peter Zijlstra
2021-11-18 10:34 ` yajun.deng
2021-11-18 10:49 ` Peter Zijlstra
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