mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
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
Subject: [RFC][PATCH 4/7] jump_label: Add static_key_{en,dis}able() helpers
Date: Fri, 24 Jul 2015 19:52:13 +0200	[thread overview]
Message-ID: <20150724175822.885518244@infradead.org> (raw)
In-Reply-To: <20150724175209.814173117@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:[~2015-07-24 18:01 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-24 17:52 [RFC][PATCH 0/7] jump_label: Another (better) static_key interface Peter Zijlstra
2015-07-24 17:52 ` [RFC][PATCH 1/7] jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE Peter Zijlstra
2015-07-24 17:52 ` [RFC][PATCH 2/7] jump_label: Rename JUMP_LABEL_TYPE_* Peter Zijlstra
2015-07-24 17:52 ` [RFC][PATCH 3/7] jump_label: Add jump_entry_key() helper Peter Zijlstra
2015-07-24 17:52 ` Peter Zijlstra [this message]
2015-07-24 17:52 ` [RFC][PATCH 5/7] jump_label: Rework update logic Peter Zijlstra
2015-07-27  9:07   ` Peter Zijlstra
2015-07-27 10:47   ` Peter Zijlstra
2015-07-27 16:30     ` Peter Zijlstra
2015-07-28  5:54       ` Heiko Carstens
2015-07-24 17:52 ` [RFC][PATCH 6/7] jump_label: Add a new static_key interface Peter Zijlstra
2015-07-27  9:24   ` Peter Zijlstra
2015-07-27  9:52   ` Peter Zijlstra
2015-07-27 10:20     ` Heiko Carstens
2015-07-27 10:47       ` Peter Zijlstra
2015-07-27 10:50         ` Peter Zijlstra
2015-07-27 10:52           ` Heiko Carstens
2015-07-27 11:03             ` Peter Zijlstra
2015-07-27 14:39             ` Peter Zijlstra
2015-07-27 10:45   ` Peter Zijlstra
2015-07-27 10:51     ` Heiko Carstens
2015-07-24 17:52 ` [RFC][PATCH 7/7] x86, tsc: Employ static_branch_likely() Peter Zijlstra

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20150724175822.885518244@infradead.org \
    --to=peterz@infradead.org \
    --cc=benh@kernel.crashing.org \
    --cc=bp@alien8.de \
    --cc=davem@davemloft.net \
    --cc=ddaney@caviumnetworks.com \
    --cc=heiko.carstens@de.ibm.com \
    --cc=jasonbaron0@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=liuj97@gmail.com \
    --cc=luto@amacapital.net \
    --cc=michael@ellerman.id.au \
    --cc=mingo@kernel.org \
    --cc=rabin@rab.in \
    --cc=ralf@linux-mips.org \
    --cc=rostedt@goodmis.org \
    --cc=tglx@linutronix.de \
    --cc=will.deacon@arm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®