* [lttng-dev] [PATCH] Fix: revise urcu_read_lock_update() comment
@ 2023-06-13 15:45 Li-Kuan Ou via lttng-dev
2023-06-13 20:16 ` Mathieu Desnoyers via lttng-dev
0 siblings, 1 reply; 4+ messages in thread
From: Li-Kuan Ou via lttng-dev @ 2023-06-13 15:45 UTC (permalink / raw)
To: lttng-dev
Read-side critical section nesting is tracked in lower-order bits
and grace-period phase number use a single high-order bit
Signed-off-by: Li-Kuan Ou <k777k777tw@gmail.com>
---
include/urcu/static/urcu-bp.h | 4 ++--
include/urcu/static/urcu-mb.h | 4 ++--
include/urcu/static/urcu-memb.h | 4 ++--
include/urcu/static/urcu-signal.h | 4 ++--
4 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/include/urcu/static/urcu-bp.h b/include/urcu/static/urcu-bp.h
index 8ba3830..c90c9f1 100644
--- a/include/urcu/static/urcu-bp.h
+++ b/include/urcu/static/urcu-bp.h
@@ -137,8 +137,8 @@ static inline enum urcu_bp_state urcu_bp_reader_state(unsigned long *ctr)
/*
* Helper for _urcu_bp_read_lock(). The format of urcu_bp_gp.ctr (as well as
- * the per-thread rcu_reader.ctr) has the upper bits containing a count of
- * _urcu_bp_read_lock() nesting, and a lower-order bit that contains either zero
+ * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
+ * _urcu_bp_read_lock() nesting, and a single high-order bit that contains either zero
* or URCU_BP_GP_CTR_PHASE. The smp_mb_slave() ensures that the accesses in
* _urcu_bp_read_lock() happen before the subsequent read-side critical section.
*/
diff --git a/include/urcu/static/urcu-mb.h b/include/urcu/static/urcu-mb.h
index b97e42a..218e2f3 100644
--- a/include/urcu/static/urcu-mb.h
+++ b/include/urcu/static/urcu-mb.h
@@ -63,8 +63,8 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_mb_reader);
/*
* Helper for _urcu_mb_read_lock(). The format of urcu_mb_gp.ctr (as well as
- * the per-thread rcu_reader.ctr) has the upper bits containing a count of
- * _urcu_mb_read_lock() nesting, and a lower-order bit that contains either zero
+ * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
+ * _urcu_mb_read_lock() nesting, and a single high-order bit that contains either zero
* or URCU_GP_CTR_PHASE. The cmm_smp_mb() ensures that the accesses in
* _urcu_mb_read_lock() happen before the subsequent read-side critical section.
*/
diff --git a/include/urcu/static/urcu-memb.h b/include/urcu/static/urcu-memb.h
index c8d102f..b923f73 100644
--- a/include/urcu/static/urcu-memb.h
+++ b/include/urcu/static/urcu-memb.h
@@ -86,8 +86,8 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_memb_reader);
/*
* Helper for _rcu_read_lock(). The format of urcu_memb_gp.ctr (as well as
- * the per-thread rcu_reader.ctr) has the upper bits containing a count of
- * _rcu_read_lock() nesting, and a lower-order bit that contains either zero
+ * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
+ * _rcu_read_lock() nesting, and a single high-order bit that contains either zero
* or URCU_GP_CTR_PHASE. The smp_mb_slave() ensures that the accesses in
* _rcu_read_lock() happen before the subsequent read-side critical section.
*/
diff --git a/include/urcu/static/urcu-signal.h b/include/urcu/static/urcu-signal.h
index c7577d3..00588b8 100644
--- a/include/urcu/static/urcu-signal.h
+++ b/include/urcu/static/urcu-signal.h
@@ -64,8 +64,8 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_signal_reader);
/*
* Helper for _rcu_read_lock(). The format of urcu_signal_gp.ctr (as well as
- * the per-thread rcu_reader.ctr) has the upper bits containing a count of
- * _rcu_read_lock() nesting, and a lower-order bit that contains either zero
+ * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
+ * _rcu_read_lock() nesting, and a single high-order bit that contains either zero
* or URCU_GP_CTR_PHASE. The cmm_barrier() ensures that the accesses in
* _rcu_read_lock() happen before the subsequent read-side critical section.
*/
--
2.34.1
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [lttng-dev] [PATCH] Fix: revise urcu_read_lock_update() comment
2023-06-13 15:45 [lttng-dev] [PATCH] Fix: revise urcu_read_lock_update() comment Li-Kuan Ou via lttng-dev
@ 2023-06-13 20:16 ` Mathieu Desnoyers via lttng-dev
2023-06-14 1:51 ` Li-Kuan Ou via lttng-dev
0 siblings, 1 reply; 4+ messages in thread
From: Mathieu Desnoyers via lttng-dev @ 2023-06-13 20:16 UTC (permalink / raw)
To: Li-Kuan Ou, lttng-dev
On 6/13/23 11:45, Li-Kuan Ou via lttng-dev wrote:
> Read-side critical section nesting is tracked in lower-order bits
> and grace-period phase number use a single high-order bit
>
Thanks for the fix. Here is a comment below,
> Signed-off-by: Li-Kuan Ou <k777k777tw@gmail.com>
> ---
> include/urcu/static/urcu-bp.h | 4 ++--
> include/urcu/static/urcu-mb.h | 4 ++--
> include/urcu/static/urcu-memb.h | 4 ++--
> include/urcu/static/urcu-signal.h | 4 ++--
> 4 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/include/urcu/static/urcu-bp.h b/include/urcu/static/urcu-bp.h
> index 8ba3830..c90c9f1 100644
> --- a/include/urcu/static/urcu-bp.h
> +++ b/include/urcu/static/urcu-bp.h
> @@ -137,8 +137,8 @@ static inline enum urcu_bp_state urcu_bp_reader_state(unsigned long *ctr)
>
> /*
> * Helper for _urcu_bp_read_lock(). The format of urcu_bp_gp.ctr (as well as
> - * the per-thread rcu_reader.ctr) has the upper bits containing a count of
> - * _urcu_bp_read_lock() nesting, and a lower-order bit that contains either zero
> + * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
> + * _urcu_bp_read_lock() nesting, and a single high-order bit that contains either zero
I think it would be clearer to state:
Helper for _urcu_bp_read_lock(). The format of urcu_bp_gp.ctr (as well as
the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
urcu_bp_read_lock() nesting, and a single high-order URCU_BP_GP_CTR_PHASE bit
that contains either zero or one. The smp_mb_slave() ensures that the accesses
in urcu_bp_read_lock() happen before the subsequent read-side critical section.
(likewise for similar comments in other files).
Can you submit an updated patch please ?
Thanks,
Mathieu
> * or URCU_BP_GP_CTR_PHASE. The smp_mb_slave() ensures that the accesses in
> * _urcu_bp_read_lock() happen before the subsequent read-side critical section.
> */
> diff --git a/include/urcu/static/urcu-mb.h b/include/urcu/static/urcu-mb.h
> index b97e42a..218e2f3 100644
> --- a/include/urcu/static/urcu-mb.h
> +++ b/include/urcu/static/urcu-mb.h
> @@ -63,8 +63,8 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_mb_reader);
>
> /*
> * Helper for _urcu_mb_read_lock(). The format of urcu_mb_gp.ctr (as well as
> - * the per-thread rcu_reader.ctr) has the upper bits containing a count of
> - * _urcu_mb_read_lock() nesting, and a lower-order bit that contains either zero
> + * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
> + * _urcu_mb_read_lock() nesting, and a single high-order bit that contains either zero
> * or URCU_GP_CTR_PHASE. The cmm_smp_mb() ensures that the accesses in
> * _urcu_mb_read_lock() happen before the subsequent read-side critical section.
> */
> diff --git a/include/urcu/static/urcu-memb.h b/include/urcu/static/urcu-memb.h
> index c8d102f..b923f73 100644
> --- a/include/urcu/static/urcu-memb.h
> +++ b/include/urcu/static/urcu-memb.h
> @@ -86,8 +86,8 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_memb_reader);
>
> /*
> * Helper for _rcu_read_lock(). The format of urcu_memb_gp.ctr (as well as
> - * the per-thread rcu_reader.ctr) has the upper bits containing a count of
> - * _rcu_read_lock() nesting, and a lower-order bit that contains either zero
> + * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
> + * _rcu_read_lock() nesting, and a single high-order bit that contains either zero
> * or URCU_GP_CTR_PHASE. The smp_mb_slave() ensures that the accesses in
> * _rcu_read_lock() happen before the subsequent read-side critical section.
> */
> diff --git a/include/urcu/static/urcu-signal.h b/include/urcu/static/urcu-signal.h
> index c7577d3..00588b8 100644
> --- a/include/urcu/static/urcu-signal.h
> +++ b/include/urcu/static/urcu-signal.h
> @@ -64,8 +64,8 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_signal_reader);
>
> /*
> * Helper for _rcu_read_lock(). The format of urcu_signal_gp.ctr (as well as
> - * the per-thread rcu_reader.ctr) has the upper bits containing a count of
> - * _rcu_read_lock() nesting, and a lower-order bit that contains either zero
> + * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
> + * _rcu_read_lock() nesting, and a single high-order bit that contains either zero
> * or URCU_GP_CTR_PHASE. The cmm_barrier() ensures that the accesses in
> * _rcu_read_lock() happen before the subsequent read-side critical section.
> */
--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com
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^ permalink raw reply [flat|nested] 4+ messages in thread
* [lttng-dev] [PATCH] Fix: revise urcu_read_lock_update() comment
2023-06-13 20:16 ` Mathieu Desnoyers via lttng-dev
@ 2023-06-14 1:51 ` Li-Kuan Ou via lttng-dev
2023-06-15 20:26 ` Mathieu Desnoyers via lttng-dev
0 siblings, 1 reply; 4+ messages in thread
From: Li-Kuan Ou via lttng-dev @ 2023-06-14 1:51 UTC (permalink / raw)
To: lttng-dev
Read-side critical section nesting is tracked in lower-order bits
and grace-period phase number use a single high-order bit
Signed-off-by: Li-Kuan Ou <k777k777tw@gmail.com>
---
include/urcu/static/urcu-bp.h | 6 +++---
include/urcu/static/urcu-mb.h | 6 +++---
include/urcu/static/urcu-memb.h | 6 +++---
include/urcu/static/urcu-signal.h | 6 +++---
4 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/include/urcu/static/urcu-bp.h b/include/urcu/static/urcu-bp.h
index 8ba3830..b163a90 100644
--- a/include/urcu/static/urcu-bp.h
+++ b/include/urcu/static/urcu-bp.h
@@ -137,9 +137,9 @@ static inline enum urcu_bp_state urcu_bp_reader_state(unsigned long *ctr)
/*
* Helper for _urcu_bp_read_lock(). The format of urcu_bp_gp.ctr (as well as
- * the per-thread rcu_reader.ctr) has the upper bits containing a count of
- * _urcu_bp_read_lock() nesting, and a lower-order bit that contains either zero
- * or URCU_BP_GP_CTR_PHASE. The smp_mb_slave() ensures that the accesses in
+ * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
+ * _urcu_bp_read_lock() nesting, and a single high-order URCU_BP_GP_CTR_PHASE bit
+ * that contains either zero or one. The smp_mb_slave() ensures that the accesses in
* _urcu_bp_read_lock() happen before the subsequent read-side critical section.
*/
static inline void _urcu_bp_read_lock_update(unsigned long tmp)
diff --git a/include/urcu/static/urcu-mb.h b/include/urcu/static/urcu-mb.h
index b97e42a..253d29b 100644
--- a/include/urcu/static/urcu-mb.h
+++ b/include/urcu/static/urcu-mb.h
@@ -63,9 +63,9 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_mb_reader);
/*
* Helper for _urcu_mb_read_lock(). The format of urcu_mb_gp.ctr (as well as
- * the per-thread rcu_reader.ctr) has the upper bits containing a count of
- * _urcu_mb_read_lock() nesting, and a lower-order bit that contains either zero
- * or URCU_GP_CTR_PHASE. The cmm_smp_mb() ensures that the accesses in
+ * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
+ * _urcu_mb_read_lock() nesting, and a single high-order URCU_BP_GP_CTR_PHASE bit
+ * that contains either zero or one. The cmm_smp_mb() ensures that the accesses in
* _urcu_mb_read_lock() happen before the subsequent read-side critical section.
*/
static inline void _urcu_mb_read_lock_update(unsigned long tmp)
diff --git a/include/urcu/static/urcu-memb.h b/include/urcu/static/urcu-memb.h
index c8d102f..f64cb57 100644
--- a/include/urcu/static/urcu-memb.h
+++ b/include/urcu/static/urcu-memb.h
@@ -86,9 +86,9 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_memb_reader);
/*
* Helper for _rcu_read_lock(). The format of urcu_memb_gp.ctr (as well as
- * the per-thread rcu_reader.ctr) has the upper bits containing a count of
- * _rcu_read_lock() nesting, and a lower-order bit that contains either zero
- * or URCU_GP_CTR_PHASE. The smp_mb_slave() ensures that the accesses in
+ * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
+ * _rcu_read_lock() nesting, and a single high-order URCU_BP_GP_CTR_PHASE bit
+ * that contains either zero or one. The smp_mb_slave() ensures that the accesses in
* _rcu_read_lock() happen before the subsequent read-side critical section.
*/
static inline void _urcu_memb_read_lock_update(unsigned long tmp)
diff --git a/include/urcu/static/urcu-signal.h b/include/urcu/static/urcu-signal.h
index c7577d3..707eaf8 100644
--- a/include/urcu/static/urcu-signal.h
+++ b/include/urcu/static/urcu-signal.h
@@ -64,9 +64,9 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_signal_reader);
/*
* Helper for _rcu_read_lock(). The format of urcu_signal_gp.ctr (as well as
- * the per-thread rcu_reader.ctr) has the upper bits containing a count of
- * _rcu_read_lock() nesting, and a lower-order bit that contains either zero
- * or URCU_GP_CTR_PHASE. The cmm_barrier() ensures that the accesses in
+ * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
+ * _rcu_read_lock() nesting, and a single high-order URCU_BP_GP_CTR_PHASE bit
+ * that contains either zero or one. The cmm_barrier() ensures that the accesses in
* _rcu_read_lock() happen before the subsequent read-side critical section.
*/
static inline void _urcu_signal_read_lock_update(unsigned long tmp)
--
2.34.1
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [lttng-dev] [PATCH] Fix: revise urcu_read_lock_update() comment
2023-06-14 1:51 ` Li-Kuan Ou via lttng-dev
@ 2023-06-15 20:26 ` Mathieu Desnoyers via lttng-dev
0 siblings, 0 replies; 4+ messages in thread
From: Mathieu Desnoyers via lttng-dev @ 2023-06-15 20:26 UTC (permalink / raw)
To: Li-Kuan Ou, lttng-dev
On 6/13/23 21:51, Li-Kuan Ou wrote:
> Read-side critical section nesting is tracked in lower-order bits
> and grace-period phase number use a single high-order bit
>
Merged, thanks!
Mathieu
> Signed-off-by: Li-Kuan Ou <k777k777tw@gmail.com>
> ---
> include/urcu/static/urcu-bp.h | 6 +++---
> include/urcu/static/urcu-mb.h | 6 +++---
> include/urcu/static/urcu-memb.h | 6 +++---
> include/urcu/static/urcu-signal.h | 6 +++---
> 4 files changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/include/urcu/static/urcu-bp.h b/include/urcu/static/urcu-bp.h
> index 8ba3830..b163a90 100644
> --- a/include/urcu/static/urcu-bp.h
> +++ b/include/urcu/static/urcu-bp.h
> @@ -137,9 +137,9 @@ static inline enum urcu_bp_state urcu_bp_reader_state(unsigned long *ctr)
>
> /*
> * Helper for _urcu_bp_read_lock(). The format of urcu_bp_gp.ctr (as well as
> - * the per-thread rcu_reader.ctr) has the upper bits containing a count of
> - * _urcu_bp_read_lock() nesting, and a lower-order bit that contains either zero
> - * or URCU_BP_GP_CTR_PHASE. The smp_mb_slave() ensures that the accesses in
> + * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
> + * _urcu_bp_read_lock() nesting, and a single high-order URCU_BP_GP_CTR_PHASE bit
> + * that contains either zero or one. The smp_mb_slave() ensures that the accesses in
> * _urcu_bp_read_lock() happen before the subsequent read-side critical section.
> */
> static inline void _urcu_bp_read_lock_update(unsigned long tmp)
> diff --git a/include/urcu/static/urcu-mb.h b/include/urcu/static/urcu-mb.h
> index b97e42a..253d29b 100644
> --- a/include/urcu/static/urcu-mb.h
> +++ b/include/urcu/static/urcu-mb.h
> @@ -63,9 +63,9 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_mb_reader);
>
> /*
> * Helper for _urcu_mb_read_lock(). The format of urcu_mb_gp.ctr (as well as
> - * the per-thread rcu_reader.ctr) has the upper bits containing a count of
> - * _urcu_mb_read_lock() nesting, and a lower-order bit that contains either zero
> - * or URCU_GP_CTR_PHASE. The cmm_smp_mb() ensures that the accesses in
> + * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
> + * _urcu_mb_read_lock() nesting, and a single high-order URCU_BP_GP_CTR_PHASE bit
> + * that contains either zero or one. The cmm_smp_mb() ensures that the accesses in
> * _urcu_mb_read_lock() happen before the subsequent read-side critical section.
> */
> static inline void _urcu_mb_read_lock_update(unsigned long tmp)
> diff --git a/include/urcu/static/urcu-memb.h b/include/urcu/static/urcu-memb.h
> index c8d102f..f64cb57 100644
> --- a/include/urcu/static/urcu-memb.h
> +++ b/include/urcu/static/urcu-memb.h
> @@ -86,9 +86,9 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_memb_reader);
>
> /*
> * Helper for _rcu_read_lock(). The format of urcu_memb_gp.ctr (as well as
> - * the per-thread rcu_reader.ctr) has the upper bits containing a count of
> - * _rcu_read_lock() nesting, and a lower-order bit that contains either zero
> - * or URCU_GP_CTR_PHASE. The smp_mb_slave() ensures that the accesses in
> + * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
> + * _rcu_read_lock() nesting, and a single high-order URCU_BP_GP_CTR_PHASE bit
> + * that contains either zero or one. The smp_mb_slave() ensures that the accesses in
> * _rcu_read_lock() happen before the subsequent read-side critical section.
> */
> static inline void _urcu_memb_read_lock_update(unsigned long tmp)
> diff --git a/include/urcu/static/urcu-signal.h b/include/urcu/static/urcu-signal.h
> index c7577d3..707eaf8 100644
> --- a/include/urcu/static/urcu-signal.h
> +++ b/include/urcu/static/urcu-signal.h
> @@ -64,9 +64,9 @@ extern DECLARE_URCU_TLS(struct urcu_reader, urcu_signal_reader);
>
> /*
> * Helper for _rcu_read_lock(). The format of urcu_signal_gp.ctr (as well as
> - * the per-thread rcu_reader.ctr) has the upper bits containing a count of
> - * _rcu_read_lock() nesting, and a lower-order bit that contains either zero
> - * or URCU_GP_CTR_PHASE. The cmm_barrier() ensures that the accesses in
> + * the per-thread rcu_reader.ctr) has the lower-order bits containing a count of
> + * _rcu_read_lock() nesting, and a single high-order URCU_BP_GP_CTR_PHASE bit
> + * that contains either zero or one. The cmm_barrier() ensures that the accesses in
> * _rcu_read_lock() happen before the subsequent read-side critical section.
> */
> static inline void _urcu_signal_read_lock_update(unsigned long tmp)
--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com
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2023-06-13 20:16 ` Mathieu Desnoyers via lttng-dev
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