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 [thread overview]
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(>od->seq);
+ seq = raw_read_seqcount_begin(>od->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(>od->seq);
+ seq = raw_read_seqcount_begin(>od->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(>od->seq);
+ seq = raw_read_seqcount_begin(>od->seq);
ts->tv_sec = gtod->wall_time_coarse.tv_sec;
ts->tv_nsec = gtod->wall_time_coarse.tv_nsec;
} while (unlikely(read_seqcount_retry(>od->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(>od->seq);
+ seq = raw_read_seqcount_begin(>od->seq);
ts->tv_sec = gtod->monotonic_time_coarse.tv_sec;
ts->tv_nsec = gtod->monotonic_time_coarse.tv_nsec;
} while (unlikely(read_seqcount_retry(>od->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
next prev parent reply other threads:[~2014-01-02 23:11 UTC|newest]
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
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