Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / Atom feed
From: john.stultz@linaro.org (John Stultz)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] seqlock: Use raw_ prefix instead of _no_lockdep
Date: Thu,  2 Jan 2014 15:11:13 -0800
Message-ID: <1388704274-5278-1-git-send-email-john.stultz@linaro.org> (raw)
In-Reply-To: <52C5E675.80701@linaro.org>

Linus disliked the _no_lockdep() naming, so instead
use the more-consistent raw_* prefix to the non-lockdep
enabled seqcount methods.

This also adds raw_ methods for the write operations
as well, which will be utilized in a following patch.

Cc: Krzysztof Ha?asa <khalasa@piap.pl>
Cc: Uwe Kleine-K?nig <u.kleine-koenig@pengutronix.de>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Ingo Molnar <mingo@kernel.org>,
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arm-kernel at lists.infradead.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 arch/x86/vdso/vclock_gettime.c |  8 ++++----
 include/linux/seqlock.h        | 27 +++++++++++++++++++--------
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index 2ada505..eb5d7a5 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -178,7 +178,7 @@ notrace static int __always_inline do_realtime(struct timespec *ts)
 
 	ts->tv_nsec = 0;
 	do {
-		seq = read_seqcount_begin_no_lockdep(&gtod->seq);
+		seq = raw_read_seqcount_begin(&gtod->seq);
 		mode = gtod->clock.vclock_mode;
 		ts->tv_sec = gtod->wall_time_sec;
 		ns = gtod->wall_time_snsec;
@@ -198,7 +198,7 @@ notrace static int do_monotonic(struct timespec *ts)
 
 	ts->tv_nsec = 0;
 	do {
-		seq = read_seqcount_begin_no_lockdep(&gtod->seq);
+		seq = raw_read_seqcount_begin(&gtod->seq);
 		mode = gtod->clock.vclock_mode;
 		ts->tv_sec = gtod->monotonic_time_sec;
 		ns = gtod->monotonic_time_snsec;
@@ -214,7 +214,7 @@ notrace static int do_realtime_coarse(struct timespec *ts)
 {
 	unsigned long seq;
 	do {
-		seq = read_seqcount_begin_no_lockdep(&gtod->seq);
+		seq = raw_read_seqcount_begin(&gtod->seq);
 		ts->tv_sec = gtod->wall_time_coarse.tv_sec;
 		ts->tv_nsec = gtod->wall_time_coarse.tv_nsec;
 	} while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
@@ -225,7 +225,7 @@ notrace static int do_monotonic_coarse(struct timespec *ts)
 {
 	unsigned long seq;
 	do {
-		seq = read_seqcount_begin_no_lockdep(&gtod->seq);
+		seq = raw_read_seqcount_begin(&gtod->seq);
 		ts->tv_sec = gtod->monotonic_time_coarse.tv_sec;
 		ts->tv_nsec = gtod->monotonic_time_coarse.tv_nsec;
 	} while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index cf87a24..535f158 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -117,15 +117,15 @@ repeat:
 }
 
 /**
- * read_seqcount_begin_no_lockdep - start seq-read critical section w/o lockdep
+ * raw_read_seqcount_begin - start seq-read critical section w/o lockdep
  * @s: pointer to seqcount_t
  * Returns: count to be passed to read_seqcount_retry
  *
- * read_seqcount_begin_no_lockdep opens a read critical section of the given
+ * raw_read_seqcount_begin opens a read critical section of the given
  * seqcount, but without any lockdep checking. Validity of the critical
  * section is tested by checking read_seqcount_retry function.
  */
-static inline unsigned read_seqcount_begin_no_lockdep(const seqcount_t *s)
+static inline unsigned raw_read_seqcount_begin(const seqcount_t *s)
 {
 	unsigned ret = __read_seqcount_begin(s);
 	smp_rmb();
@@ -144,7 +144,7 @@ static inline unsigned read_seqcount_begin_no_lockdep(const seqcount_t *s)
 static inline unsigned read_seqcount_begin(const seqcount_t *s)
 {
 	seqcount_lockdep_reader_access(s);
-	return read_seqcount_begin_no_lockdep(s);
+	return raw_read_seqcount_begin(s);
 }
 
 /**
@@ -206,14 +206,26 @@ static inline int read_seqcount_retry(const seqcount_t *s, unsigned start)
 }
 
 
+
+static inline void raw_write_seqcount_begin(seqcount_t *s)
+{
+	s->sequence++;
+	smp_wmb();
+}
+
+static inline void raw_write_seqcount_end(seqcount_t *s)
+{
+	smp_wmb();
+	s->sequence++;
+}
+
 /*
  * Sequence counter only version assumes that callers are using their
  * own mutexing.
  */
 static inline void write_seqcount_begin_nested(seqcount_t *s, int subclass)
 {
-	s->sequence++;
-	smp_wmb();
+	raw_write_seqcount_begin(s);
 	seqcount_acquire(&s->dep_map, subclass, 0, _RET_IP_);
 }
 
@@ -225,8 +237,7 @@ static inline void write_seqcount_begin(seqcount_t *s)
 static inline void write_seqcount_end(seqcount_t *s)
 {
 	seqcount_release(&s->dep_map, 1, _RET_IP_);
-	smp_wmb();
-	s->sequence++;
+	raw_write_seqcount_end(s);
 }
 
 /**
-- 
1.8.3.2

  reply index

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-31 10:37 v3.13-rc6+ regression (ARM board) Krzysztof Hałasa
2013-12-31 10:45 ` Willy Tarreau
2014-01-02 10:02   ` Krzysztof Hałasa
2014-01-02 10:14     ` Uwe Kleine-König
2014-01-02 12:07       ` Krzysztof Hałasa
2014-01-02 19:38         ` Linus Torvalds
2014-01-02 20:03           ` John Stultz
2014-01-02 20:30             ` John Stultz
2014-01-02 20:42               ` Stephen Boyd
2014-01-02 20:52                 ` John Stultz
2014-01-02 20:43               ` Linus Torvalds
2014-01-02 21:34                 ` John Stultz
2014-01-02 21:54                   ` [PATCH] sched_clock: Disable seqlock lockdep usage in sched_clock John Stultz
2014-01-02 22:15                     ` Linus Torvalds
2014-01-02 22:21                       ` John Stultz
2014-01-02 23:11                         ` John Stultz [this message]
2014-01-02 23:11                           ` [PATCH 2/2] " John Stultz
2014-01-03  0:46                             ` Stephen Boyd
2014-01-03  6:05                             ` Krzysztof Hałasa
2014-01-03  0:46                           ` [PATCH 1/2] seqlock: Use raw_ prefix instead of _no_lockdep Stephen Boyd
2014-01-03  0:50                           ` Linus Torvalds
2014-01-04  0:28                             ` John Stultz
2014-01-06 10:10                               ` Peter Zijlstra
2014-01-03  6:01           ` v3.13-rc6+ regression (ARM board) Krzysztof Hałasa

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=1388704274-5278-1-git-send-email-john.stultz@linaro.org \
    --to=john.stultz@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    /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

Linux-ARM-Kernel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/0 linux-arm-kernel/git/0.git
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/1 linux-arm-kernel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ https://lore.kernel.org/linux-arm-kernel \
		linux-arm-kernel@lists.infradead.org
	public-inbox-index linux-arm-kernel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-arm-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git