* [PATCH] rcu: Remove the unnecessary separate function, rcu_preempt_do_callback()
@ 2018-02-26 5:11 Byungchul Park
2018-02-26 17:15 ` Steven Rostedt
0 siblings, 1 reply; 6+ messages in thread
From: Byungchul Park @ 2018-02-26 5:11 UTC (permalink / raw)
To: jiangshanlai, paulmck, josh, rostedt, mathieu.desnoyers
Cc: linux-kernel, kernel-team
rcu_preemptp_do_callback() was introduced in commit 09223371dea(rcu:
Use softirq to address performance regression), where it had to be
distinguished between in the case CONFIG_TREE_PREEMPT_RCU is set and
it's not.
Now that the code was cleaned up so that rcu_preemt_do_callback() is
only called in rcu_kthread_do_work() in the same file, tree_plugin.h,
we don't have to keep the separate function anymore. Remove it for a
better readability.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
---
kernel/rcu/tree.h | 1 -
kernel/rcu/tree_plugin.h | 11 +----------
2 files changed, 1 insertion(+), 11 deletions(-)
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 478b79e..4172833 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -439,7 +439,6 @@ struct rcu_state {
static void invoke_rcu_callbacks_kthread(void);
static bool rcu_is_callbacks_kthread(void);
#ifdef CONFIG_RCU_BOOST
-static void rcu_preempt_do_callbacks(void);
static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
struct rcu_node *rnp);
#endif /* #ifdef CONFIG_RCU_BOOST */
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 26d7a31..1070a04 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -686,15 +686,6 @@ static void rcu_preempt_check_callbacks(void)
t->rcu_read_unlock_special.b.need_qs = true;
}
-#ifdef CONFIG_RCU_BOOST
-
-static void rcu_preempt_do_callbacks(void)
-{
- rcu_do_batch(rcu_state_p, this_cpu_ptr(rcu_data_p));
-}
-
-#endif /* #ifdef CONFIG_RCU_BOOST */
-
/**
* call_rcu() - Queue an RCU callback for invocation after a grace period.
* @head: structure to be used for queueing the RCU updates.
@@ -1170,7 +1161,7 @@ static void rcu_kthread_do_work(void)
{
rcu_do_batch(&rcu_sched_state, this_cpu_ptr(&rcu_sched_data));
rcu_do_batch(&rcu_bh_state, this_cpu_ptr(&rcu_bh_data));
- rcu_preempt_do_callbacks();
+ rcu_do_batch(rcu_state_p, this_cpu_ptr(rcu_data_p));
}
static void rcu_cpu_kthread_setup(unsigned int cpu)
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] rcu: Remove the unnecessary separate function, rcu_preempt_do_callback()
2018-02-26 5:11 [PATCH] rcu: Remove the unnecessary separate function, rcu_preempt_do_callback() Byungchul Park
@ 2018-02-26 17:15 ` Steven Rostedt
2018-02-26 18:22 ` Paul E. McKenney
0 siblings, 1 reply; 6+ messages in thread
From: Steven Rostedt @ 2018-02-26 17:15 UTC (permalink / raw)
To: Byungchul Park
Cc: jiangshanlai, paulmck, josh, mathieu.desnoyers, linux-kernel,
kernel-team
On Mon, 26 Feb 2018 14:11:36 +0900
Byungchul Park <byungchul.park@lge.com> wrote:
> rcu_preemptp_do_callback() was introduced in commit 09223371dea(rcu:
> Use softirq to address performance regression), where it had to be
> distinguished between in the case CONFIG_TREE_PREEMPT_RCU is set and
> it's not.
>
> Now that the code was cleaned up so that rcu_preemt_do_callback() is
> only called in rcu_kthread_do_work() in the same file, tree_plugin.h,
> we don't have to keep the separate function anymore. Remove it for a
> better readability.
Looks good to me (looks like commit f8b7fc6b51 "rcu: use softirq
instead of kthreads except when RCU_BOOST=y" cleaned up the ifdefs and
removed the requirement).
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] rcu: Remove the unnecessary separate function, rcu_preempt_do_callback()
2018-02-26 17:15 ` Steven Rostedt
@ 2018-02-26 18:22 ` Paul E. McKenney
2018-02-26 23:35 ` Byungchul Park
0 siblings, 1 reply; 6+ messages in thread
From: Paul E. McKenney @ 2018-02-26 18:22 UTC (permalink / raw)
To: Steven Rostedt
Cc: Byungchul Park, jiangshanlai, josh, mathieu.desnoyers,
linux-kernel, kernel-team
On Mon, Feb 26, 2018 at 12:15:14PM -0500, Steven Rostedt wrote:
> On Mon, 26 Feb 2018 14:11:36 +0900
> Byungchul Park <byungchul.park@lge.com> wrote:
>
> > rcu_preemptp_do_callback() was introduced in commit 09223371dea(rcu:
> > Use softirq to address performance regression), where it had to be
> > distinguished between in the case CONFIG_TREE_PREEMPT_RCU is set and
> > it's not.
> >
> > Now that the code was cleaned up so that rcu_preemt_do_callback() is
> > only called in rcu_kthread_do_work() in the same file, tree_plugin.h,
> > we don't have to keep the separate function anymore. Remove it for a
> > better readability.
>
> Looks good to me (looks like commit f8b7fc6b51 "rcu: use softirq
> instead of kthreads except when RCU_BOOST=y" cleaned up the ifdefs and
> removed the requirement).
>
> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Thank you both! I have queued a slightly modified patch for testing
and further review. Please see below and let me know if I messed
something up.
Thanx, Paul
------------------------------------------------------------------------
commit b8a3012ddba397d4a18d9fd4a00432f8c2626bd6
Author: Byungchul Park <byungchul.park@lge.com>
Date: Mon Feb 26 14:11:36 2018 +0900
rcu: Inline rcu_preempt_do_callback() into its sole caller
The rcu_preempt_do_callbacks() function was introduced in commit
09223371dea(rcu: Use softirq to address performance regression), where it
was necessary to handle kernel builds both containing and not containing
RCU-preempt. Since then, various changes (most notably f8b7fc6b51
("rcu: use softirq instead of kthreads except when RCU_BOOST=y")) have
resulted in this function being invoked only from rcu_kthread_do_work(),
which is present only in kernels containing RCU-preempt, which in turn
means that the rcu_preempt_do_callbacks() function is no longer needed.
This commit therefore inlines rcu_preempt_do_callbacks() into its
sole remaining caller and also removes the rcu_state_p and rcu_data_p
indirection for added clarity.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[ paulmck: Remove the rcu_state_p and rcu_data_p indirection. ]
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index dc6f2319fc21..9dd0ea77faed 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -449,7 +449,6 @@ static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
static void invoke_rcu_callbacks_kthread(void);
static bool rcu_is_callbacks_kthread(void);
#ifdef CONFIG_RCU_BOOST
-static void rcu_preempt_do_callbacks(void);
static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
struct rcu_node *rnp);
#endif /* #ifdef CONFIG_RCU_BOOST */
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 26d7a31e81cb..b0d7f9ba6bf2 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -686,15 +686,6 @@ static void rcu_preempt_check_callbacks(void)
t->rcu_read_unlock_special.b.need_qs = true;
}
-#ifdef CONFIG_RCU_BOOST
-
-static void rcu_preempt_do_callbacks(void)
-{
- rcu_do_batch(rcu_state_p, this_cpu_ptr(rcu_data_p));
-}
-
-#endif /* #ifdef CONFIG_RCU_BOOST */
-
/**
* call_rcu() - Queue an RCU callback for invocation after a grace period.
* @head: structure to be used for queueing the RCU updates.
@@ -1170,7 +1161,7 @@ static void rcu_kthread_do_work(void)
{
rcu_do_batch(&rcu_sched_state, this_cpu_ptr(&rcu_sched_data));
rcu_do_batch(&rcu_bh_state, this_cpu_ptr(&rcu_bh_data));
- rcu_preempt_do_callbacks();
+ rcu_do_batch(&rcu_preempt_state, this_cpu_ptr(&rcu_preempt_data));
}
static void rcu_cpu_kthread_setup(unsigned int cpu)
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] rcu: Remove the unnecessary separate function, rcu_preempt_do_callback()
2018-02-26 18:22 ` Paul E. McKenney
@ 2018-02-26 23:35 ` Byungchul Park
2018-02-26 23:40 ` Byungchul Park
0 siblings, 1 reply; 6+ messages in thread
From: Byungchul Park @ 2018-02-26 23:35 UTC (permalink / raw)
To: paulmck, Steven Rostedt
Cc: jiangshanlai, josh, mathieu.desnoyers, linux-kernel, kernel-team
On 2/27/2018 3:22 AM, Paul E. McKenney wrote:
> On Mon, Feb 26, 2018 at 12:15:14PM -0500, Steven Rostedt wrote:
>> On Mon, 26 Feb 2018 14:11:36 +0900
>> Byungchul Park <byungchul.park@lge.com> wrote:
>>
>>> rcu_preemptp_do_callback() was introduced in commit 09223371dea(rcu:
>>> Use softirq to address performance regression), where it had to be
>>> distinguished between in the case CONFIG_TREE_PREEMPT_RCU is set and
>>> it's not.
>>>
>>> Now that the code was cleaned up so that rcu_preemt_do_callback() is
>>> only called in rcu_kthread_do_work() in the same file, tree_plugin.h,
>>> we don't have to keep the separate function anymore. Remove it for a
>>> better readability.
>>
>> Looks good to me (looks like commit f8b7fc6b51 "rcu: use softirq
>> instead of kthreads except when RCU_BOOST=y" cleaned up the ifdefs and
>> removed the requirement).
>>
>> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
>
> Thank you both! I have queued a slightly modified patch for testing
> and further review. Please see below and let me know if I messed
> something up.
>
> Thanx, Paul
>
> ------------------------------------------------------------------------
>
> commit b8a3012ddba397d4a18d9fd4a00432f8c2626bd6
> Author: Byungchul Park <byungchul.park@lge.com>
> Date: Mon Feb 26 14:11:36 2018 +0900
>
> rcu: Inline rcu_preempt_do_callback() into its sole caller
>
> The rcu_preempt_do_callbacks() function was introduced in commit
> 09223371dea(rcu: Use softirq to address performance regression), where it
> was necessary to handle kernel builds both containing and not containing
> RCU-preempt. Since then, various changes (most notably f8b7fc6b51
> ("rcu: use softirq instead of kthreads except when RCU_BOOST=y")) have
> resulted in this function being invoked only from rcu_kthread_do_work(),
> which is present only in kernels containing RCU-preempt, which in turn
> means that the rcu_preempt_do_callbacks() function is no longer needed.
>
> This commit therefore inlines rcu_preempt_do_callbacks() into its
> sole remaining caller and also removes the rcu_state_p and rcu_data_p
> indirection for added clarity.
>
> Signed-off-by: Byungchul Park <byungchul.park@lge.com>
> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> [ paulmck: Remove the rcu_state_p and rcu_data_p indirection. ]
>
> diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
> index dc6f2319fc21..9dd0ea77faed 100644
> --- a/kernel/rcu/tree.h
> +++ b/kernel/rcu/tree.h
> @@ -449,7 +449,6 @@ static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
> static void invoke_rcu_callbacks_kthread(void);
> static bool rcu_is_callbacks_kthread(void);
> #ifdef CONFIG_RCU_BOOST
> -static void rcu_preempt_do_callbacks(void);
> static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
> struct rcu_node *rnp);
> #endif /* #ifdef CONFIG_RCU_BOOST */
> diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
> index 26d7a31e81cb..b0d7f9ba6bf2 100644
> --- a/kernel/rcu/tree_plugin.h
> +++ b/kernel/rcu/tree_plugin.h
> @@ -686,15 +686,6 @@ static void rcu_preempt_check_callbacks(void)
> t->rcu_read_unlock_special.b.need_qs = true;
> }
>
> -#ifdef CONFIG_RCU_BOOST
> -
> -static void rcu_preempt_do_callbacks(void)
> -{
> - rcu_do_batch(rcu_state_p, this_cpu_ptr(rcu_data_p));
> -}
> -
> -#endif /* #ifdef CONFIG_RCU_BOOST */
> -
> /**
> * call_rcu() - Queue an RCU callback for invocation after a grace period.
> * @head: structure to be used for queueing the RCU updates.
> @@ -1170,7 +1161,7 @@ static void rcu_kthread_do_work(void)
> {
> rcu_do_batch(&rcu_sched_state, this_cpu_ptr(&rcu_sched_data));
> rcu_do_batch(&rcu_bh_state, this_cpu_ptr(&rcu_bh_data));
> - rcu_preempt_do_callbacks();
> + rcu_do_batch(&rcu_preempt_state, this_cpu_ptr(&rcu_preempt_data));
OMG. Sorry for the mistake and thank you very much for fixing it.
I will be more careful.
--
Thanks,
Byungchul
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] rcu: Remove the unnecessary separate function, rcu_preempt_do_callback()
2018-02-26 23:35 ` Byungchul Park
@ 2018-02-26 23:40 ` Byungchul Park
2018-02-26 23:55 ` Paul E. McKenney
0 siblings, 1 reply; 6+ messages in thread
From: Byungchul Park @ 2018-02-26 23:40 UTC (permalink / raw)
To: paulmck, Steven Rostedt
Cc: jiangshanlai, josh, mathieu.desnoyers, linux-kernel, kernel-team
On 2/27/2018 8:35 AM, Byungchul Park wrote:
> On 2/27/2018 3:22 AM, Paul E. McKenney wrote:
>> On Mon, Feb 26, 2018 at 12:15:14PM -0500, Steven Rostedt wrote:
>>> On Mon, 26 Feb 2018 14:11:36 +0900
>>> Byungchul Park <byungchul.park@lge.com> wrote:
>>>
>>>> rcu_preemptp_do_callback() was introduced in commit 09223371dea(rcu:
>>>> Use softirq to address performance regression), where it had to be
>>>> distinguished between in the case CONFIG_TREE_PREEMPT_RCU is set and
>>>> it's not.
>>>>
>>>> Now that the code was cleaned up so that rcu_preemt_do_callback() is
>>>> only called in rcu_kthread_do_work() in the same file, tree_plugin.h,
>>>> we don't have to keep the separate function anymore. Remove it for a
>>>> better readability.
>>>
>>> Looks good to me (looks like commit f8b7fc6b51 "rcu: use softirq
>>> instead of kthreads except when RCU_BOOST=y" cleaned up the ifdefs and
>>> removed the requirement).
>>>
>>> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
>>
>> Thank you both! I have queued a slightly modified patch for testing
>> and further review. Please see below and let me know if I messed
>> something up.
>>
>> Thanx, Paul
>>
>> ------------------------------------------------------------------------
>>
>> commit b8a3012ddba397d4a18d9fd4a00432f8c2626bd6
>> Author: Byungchul Park <byungchul.park@lge.com>
>> Date: Mon Feb 26 14:11:36 2018 +0900
>>
>> rcu: Inline rcu_preempt_do_callback() into its sole caller
>> The rcu_preempt_do_callbacks() function was introduced in commit
>> 09223371dea(rcu: Use softirq to address performance regression),
>> where it
>> was necessary to handle kernel builds both containing and not
>> containing
>> RCU-preempt. Since then, various changes (most notably f8b7fc6b51
>> ("rcu: use softirq instead of kthreads except when RCU_BOOST=y"))
>> have
>> resulted in this function being invoked only from
>> rcu_kthread_do_work(),
>> which is present only in kernels containing RCU-preempt, which in
>> turn
>> means that the rcu_preempt_do_callbacks() function is no longer
>> needed.
>> This commit therefore inlines rcu_preempt_do_callbacks() into its
>> sole remaining caller and also removes the rcu_state_p and
>> rcu_data_p
>> indirection for added clarity.
>> Signed-off-by: Byungchul Park <byungchul.park@lge.com>
>> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
>> [ paulmck: Remove the rcu_state_p and rcu_data_p indirection. ]
>>
>> diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
>> index dc6f2319fc21..9dd0ea77faed 100644
>> --- a/kernel/rcu/tree.h
>> +++ b/kernel/rcu/tree.h
>> @@ -449,7 +449,6 @@ static void rcu_preempt_boost_start_gp(struct
>> rcu_node *rnp);
>> static void invoke_rcu_callbacks_kthread(void);
>> static bool rcu_is_callbacks_kthread(void);
>> #ifdef CONFIG_RCU_BOOST
>> -static void rcu_preempt_do_callbacks(void);
>> static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
>> struct rcu_node *rnp);
>> #endif /* #ifdef CONFIG_RCU_BOOST */
>> diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
>> index 26d7a31e81cb..b0d7f9ba6bf2 100644
>> --- a/kernel/rcu/tree_plugin.h
>> +++ b/kernel/rcu/tree_plugin.h
>> @@ -686,15 +686,6 @@ static void rcu_preempt_check_callbacks(void)
>> t->rcu_read_unlock_special.b.need_qs = true;
>> }
>> -#ifdef CONFIG_RCU_BOOST
>> -
>> -static void rcu_preempt_do_callbacks(void)
>> -{
>> - rcu_do_batch(rcu_state_p, this_cpu_ptr(rcu_data_p));
>> -}
>> -
>> -#endif /* #ifdef CONFIG_RCU_BOOST */
>> -
>> /**
>> * call_rcu() - Queue an RCU callback for invocation after a grace
>> period.
>> * @head: structure to be used for queueing the RCU updates.
>> @@ -1170,7 +1161,7 @@ static void rcu_kthread_do_work(void)
>> {
>> rcu_do_batch(&rcu_sched_state, this_cpu_ptr(&rcu_sched_data));
>> rcu_do_batch(&rcu_bh_state, this_cpu_ptr(&rcu_bh_data));
>> - rcu_preempt_do_callbacks();
>> + rcu_do_batch(&rcu_preempt_state, this_cpu_ptr(&rcu_preempt_data));
>
> OMG. Sorry for the mistake and thank you very much for fixing it.
>
> I will be more careful.
Ah. Logically no difference between mine and your fixed one.
But anyway yours looks much better! Thank you~ :)
--
Thanks,
Byungchul
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] rcu: Remove the unnecessary separate function, rcu_preempt_do_callback()
2018-02-26 23:40 ` Byungchul Park
@ 2018-02-26 23:55 ` Paul E. McKenney
0 siblings, 0 replies; 6+ messages in thread
From: Paul E. McKenney @ 2018-02-26 23:55 UTC (permalink / raw)
To: Byungchul Park
Cc: Steven Rostedt, jiangshanlai, josh, mathieu.desnoyers,
linux-kernel, kernel-team
On Tue, Feb 27, 2018 at 08:40:47AM +0900, Byungchul Park wrote:
> On 2/27/2018 8:35 AM, Byungchul Park wrote:
> >On 2/27/2018 3:22 AM, Paul E. McKenney wrote:
> >>On Mon, Feb 26, 2018 at 12:15:14PM -0500, Steven Rostedt wrote:
> >>>On Mon, 26 Feb 2018 14:11:36 +0900
> >>>Byungchul Park <byungchul.park@lge.com> wrote:
> >>>
> >>>>rcu_preemptp_do_callback() was introduced in commit 09223371dea(rcu:
> >>>>Use softirq to address performance regression), where it had to be
> >>>>distinguished between in the case CONFIG_TREE_PREEMPT_RCU is set and
> >>>>it's not.
> >>>>
> >>>>Now that the code was cleaned up so that rcu_preemt_do_callback() is
> >>>>only called in rcu_kthread_do_work() in the same file, tree_plugin.h,
> >>>>we don't have to keep the separate function anymore. Remove it for a
> >>>>better readability.
> >>>
> >>>Looks good to me (looks like commit f8b7fc6b51 "rcu: use softirq
> >>>instead of kthreads except when RCU_BOOST=y" cleaned up the ifdefs and
> >>>removed the requirement).
> >>>
> >>>Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> >>
> >>Thank you both! I have queued a slightly modified patch for testing
> >>and further review. Please see below and let me know if I messed
> >>something up.
> >>
> >> Thanx, Paul
> >>
> >>------------------------------------------------------------------------
> >>
> >>commit b8a3012ddba397d4a18d9fd4a00432f8c2626bd6
> >>Author: Byungchul Park <byungchul.park@lge.com>
> >>Date: Mon Feb 26 14:11:36 2018 +0900
> >>
> >> rcu: Inline rcu_preempt_do_callback() into its sole caller
> >> The rcu_preempt_do_callbacks() function was introduced in commit
> >> 09223371dea(rcu: Use softirq to address performance
> >>regression), where it
> >> was necessary to handle kernel builds both containing and
> >>not containing
> >> RCU-preempt. Since then, various changes (most notably f8b7fc6b51
> >> ("rcu: use softirq instead of kthreads except when
> >>RCU_BOOST=y")) have
> >> resulted in this function being invoked only from
> >>rcu_kthread_do_work(),
> >> which is present only in kernels containing RCU-preempt,
> >>which in turn
> >> means that the rcu_preempt_do_callbacks() function is no
> >>longer needed.
> >> This commit therefore inlines rcu_preempt_do_callbacks() into its
> >> sole remaining caller and also removes the rcu_state_p and
> >>rcu_data_p
> >> indirection for added clarity.
> >> Signed-off-by: Byungchul Park <byungchul.park@lge.com>
> >> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> >> [ paulmck: Remove the rcu_state_p and rcu_data_p indirection. ]
> >>
> >>diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
> >>index dc6f2319fc21..9dd0ea77faed 100644
> >>--- a/kernel/rcu/tree.h
> >>+++ b/kernel/rcu/tree.h
> >>@@ -449,7 +449,6 @@ static void
> >>rcu_preempt_boost_start_gp(struct rcu_node *rnp);
> >> static void invoke_rcu_callbacks_kthread(void);
> >> static bool rcu_is_callbacks_kthread(void);
> >> #ifdef CONFIG_RCU_BOOST
> >>-static void rcu_preempt_do_callbacks(void);
> >> static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
> >> struct rcu_node *rnp);
> >> #endif /* #ifdef CONFIG_RCU_BOOST */
> >>diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
> >>index 26d7a31e81cb..b0d7f9ba6bf2 100644
> >>--- a/kernel/rcu/tree_plugin.h
> >>+++ b/kernel/rcu/tree_plugin.h
> >>@@ -686,15 +686,6 @@ static void rcu_preempt_check_callbacks(void)
> >> t->rcu_read_unlock_special.b.need_qs = true;
> >> }
> >>-#ifdef CONFIG_RCU_BOOST
> >>-
> >>-static void rcu_preempt_do_callbacks(void)
> >>-{
> >>- rcu_do_batch(rcu_state_p, this_cpu_ptr(rcu_data_p));
> >>-}
> >>-
> >>-#endif /* #ifdef CONFIG_RCU_BOOST */
> >>-
> >> /**
> >> * call_rcu() - Queue an RCU callback for invocation after a
> >>grace period.
> >> * @head: structure to be used for queueing the RCU updates.
> >>@@ -1170,7 +1161,7 @@ static void rcu_kthread_do_work(void)
> >> {
> >> rcu_do_batch(&rcu_sched_state, this_cpu_ptr(&rcu_sched_data));
> >> rcu_do_batch(&rcu_bh_state, this_cpu_ptr(&rcu_bh_data));
> >>- rcu_preempt_do_callbacks();
> >>+ rcu_do_batch(&rcu_preempt_state, this_cpu_ptr(&rcu_preempt_data));
> >
> >OMG. Sorry for the mistake and thank you very much for fixing it.
> >
> >I will be more careful.
>
> Ah. Logically no difference between mine and your fixed one.
Yes, your patch was perfectly fine. It just kept an additional pair of
memory fetches that are unnecessary. So if you considered your patch
to have a problem, then the original code had that same problem.
> But anyway yours looks much better! Thank you~ :)
And you!
Thanx, Paul
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-02-26 23:55 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-02-26 5:11 [PATCH] rcu: Remove the unnecessary separate function, rcu_preempt_do_callback() Byungchul Park
2018-02-26 17:15 ` Steven Rostedt
2018-02-26 18:22 ` Paul E. McKenney
2018-02-26 23:35 ` Byungchul Park
2018-02-26 23:40 ` Byungchul Park
2018-02-26 23:55 ` Paul E. McKenney
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