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From: Peter Zijlstra <peterz@infradead.org>
To: linux-kernel@vger.kernel.org, mingo@kernel.org
Cc: jasonbaron0@gmail.com, bp@alien8.de, luto@amacapital.net,
	tglx@linutronix.de, rostedt@goodmis.org, will.deacon@arm.com,
	liuj97@gmail.com, rabin@rab.in, ralf@linux-mips.org,
	ddaney@caviumnetworks.com, benh@kernel.crashing.org,
	michael@ellerman.id.au, heiko.carstens@de.ibm.com,
	davem@davemloft.net, peterz@infradead.org, vbabka@suse.cz
Subject: [PATCH -v2 4/8] jump_label: Add static_key_{en,dis}able() helpers
Date: Tue, 28 Jul 2015 15:20:59 +0200	[thread overview]
Message-ID: <20150728132312.955575171@infradead.org> (raw)
In-Reply-To: <20150728132055.203176565@infradead.org>

[-- Attachment #1: peterz-static-key-bool.patch --]
[-- Type: text/plain, Size: 1485 bytes --]

Add two helpers to make it easier to treat the refcount as boolean.

Suggested-by: Jason Baron <jasonbaron0@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 include/linux/jump_label.h |   20 ++++++++++++++++++++
 kernel/sched/core.c        |    6 ++----
 2 files changed, 22 insertions(+), 4 deletions(-)

--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -198,6 +198,26 @@ static inline bool static_key_enabled(st
 	return static_key_count(key) > 0;
 }
 
+static inline void static_key_enable(struct static_key *key)
+{
+	int count = static_key_count(key);
+
+	WARN_ON_ONCE(count < 0 || count > 1);
+
+	if (!count)
+		static_key_slow_inc(key);
+}
+
+static inline void static_key_disable(struct static_key *key)
+{
+	int count = static_key_count(key);
+
+	WARN_ON_ONCE(count < 0 || count > 1);
+
+	if (count)
+		static_key_slow_dec(key);
+}
+
 #endif	/* _LINUX_JUMP_LABEL_H */
 
 #endif /* __ASSEMBLY__ */
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -164,14 +164,12 @@ struct static_key sched_feat_keys[__SCHE
 
 static void sched_feat_disable(int i)
 {
-	if (static_key_enabled(&sched_feat_keys[i]))
-		static_key_slow_dec(&sched_feat_keys[i]);
+	static_key_disable(&sched_feat_keys[i]);
 }
 
 static void sched_feat_enable(int i)
 {
-	if (!static_key_enabled(&sched_feat_keys[i]))
-		static_key_slow_inc(&sched_feat_keys[i]);
+	static_key_enable(&sched_feat_keys[i]);
 }
 #else
 static void sched_feat_disable(int i) { };



  parent reply	other threads:[~2015-07-28 13:26 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-28 13:20 [PATCH -v2 0/8] jump_label: Another (better) static_key interface Peter Zijlstra
2015-07-28 13:20 ` [PATCH -v2 1/8] jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE Peter Zijlstra
2015-07-28 13:20 ` [PATCH -v2 2/8] jump_label: Rename JUMP_LABEL_TYPE_* Peter Zijlstra
2015-07-29 12:58   ` Borislav Petkov
2015-07-28 13:20 ` [PATCH -v2 3/8] jump_label: Add jump_entry_key() helper Peter Zijlstra
2015-07-28 13:20 ` Peter Zijlstra [this message]
2015-07-28 13:21 ` [PATCH -v2 5/8] jump_label: Rework update logic Peter Zijlstra
2015-07-28 13:21 ` [PATCH -v2 6/8] jump_label: Add a new static_key interface Peter Zijlstra
2015-07-28 17:00   ` Rabin Vincent
2015-07-28 17:20     ` Peter Zijlstra
2015-07-29  6:43   ` Heiko Carstens
2015-07-29  7:19   ` Vlastimil Babka
2015-07-29  8:49     ` Peter Zijlstra
2015-08-03 19:03       ` Steven Rostedt
2015-08-03 19:18         ` Peter Zijlstra
2015-08-03 19:28           ` Steven Rostedt
2015-08-03 20:00             ` Peter Zijlstra
2015-08-03 21:57               ` Steven Rostedt
2015-08-04  3:37                 ` Borislav Petkov
2015-08-04  4:07                   ` Andy Lutomirski
2015-08-04  4:21                     ` Borislav Petkov
2015-08-04 12:06                   ` Steven Rostedt
2015-08-04 14:33                     ` Borislav Petkov
2015-08-04 14:41                       ` Steven Rostedt
2015-08-04 14:51                       ` Andy Lutomirski
2015-07-30 12:18   ` Michael Ellerman
2015-08-04  6:50   ` yalin wang
2015-08-04  9:15     ` Peter Zijlstra
2015-07-28 13:21 ` [PATCH -v2 7/8] jump_label: Add selftest Peter Zijlstra
2015-07-28 21:46   ` Jason Baron
2015-07-29  8:53     ` Peter Zijlstra
2015-07-28 13:21 ` [PATCH -v2 8/8] x86, tsc: Employ static_branch_likely() Peter Zijlstra
2015-07-29 14:07   ` Borislav Petkov
2015-07-29  6:46 ` [PATCH -v2 0/8] jump_label: Another (better) static_key interface Heiko Carstens
2015-07-29  8:58   ` Peter Zijlstra
2015-08-03 17:03   ` [tip:locking/core] s390/uaccess, locking/static_keys: employ static_branch_likely() tip-bot for Heiko Carstens

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