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) { };
next prev 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
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=20150728132312.955575171@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=vbabka@suse.cz \
--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®