LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
* [PATCH RESEND v2] sched/deadline: fix rt runtime corrupt when dl refuse a smaller bandwidth
@ 2015-02-25  4:37 Wanpeng Li
  2015-02-26  9:55 ` Juri Lelli
  0 siblings, 1 reply; 5+ messages in thread
From: Wanpeng Li @ 2015-02-25  4:37 UTC (permalink / raw)
  To: Ingo Molnar, Peter Zijlstra
  Cc: Juri Lelli, juri.lelli, linux-kernel, Wanpeng Li

Dl class will refuse the bandwidth being set to some value smaller
than the currently allocated bandwidth in any of the root_domains
through sched_rt_runtime_us and sched_rt_period_us. RT runtime will
be set according to sched_rt_runtime_us before dl class verify if
the new bandwidth is suitable in the case of !CONFIG_RT_GROUP_SCHED.

However, rt runtime will be corrupt if dl refuse the new bandwidth
since there is no undo to reset the rt runtime to the old value.

This patch fix it by verifying new bandwidth for deadline in advance.

Cc: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
---
v1 -> v2:
 * move sched_dl_global_constraints before sched_rt_global_constraints,
   and change the name of the former to sched_dl_global_validate().

 kernel/sched/core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 97fe79c..e884909 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7815,7 +7815,7 @@ static int sched_rt_global_constraints(void)
 }
 #endif /* CONFIG_RT_GROUP_SCHED */
 
-static int sched_dl_global_constraints(void)
+static int sched_dl_global_validate(void)
 {
 	u64 runtime = global_rt_runtime();
 	u64 period = global_rt_period();
@@ -7916,11 +7916,11 @@ int sched_rt_handler(struct ctl_table *table, int write,
 		if (ret)
 			goto undo;
 
-		ret = sched_rt_global_constraints();
+		ret = sched_dl_global_validate();
 		if (ret)
 			goto undo;
 
-		ret = sched_dl_global_constraints();
+		ret = sched_rt_global_constraints();
 		if (ret)
 			goto undo;
 
-- 
1.9.1


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH RESEND v2] sched/deadline: fix rt runtime corrupt when dl refuse a smaller bandwidth
  2015-02-25  4:37 [PATCH RESEND v2] sched/deadline: fix rt runtime corrupt when dl refuse a smaller bandwidth Wanpeng Li
@ 2015-02-26  9:55 ` Juri Lelli
  0 siblings, 0 replies; 5+ messages in thread
From: Juri Lelli @ 2015-02-26  9:55 UTC (permalink / raw)
  To: Wanpeng Li, Ingo Molnar, Peter Zijlstra; +Cc: juri.lelli, linux-kernel

Hi,

On 25/02/2015 04:37, Wanpeng Li wrote:
> Dl class will refuse the bandwidth being set to some value smaller
> than the currently allocated bandwidth in any of the root_domains
> through sched_rt_runtime_us and sched_rt_period_us. RT runtime will
> be set according to sched_rt_runtime_us before dl class verify if
> the new bandwidth is suitable in the case of !CONFIG_RT_GROUP_SCHED.
> 
> However, rt runtime will be corrupt if dl refuse the new bandwidth
> since there is no undo to reset the rt runtime to the old value.
> 
> This patch fix it by verifying new bandwidth for deadline in advance.
> 

Looks good, thanks!

Acked-by: Juri Lelli <juri.lelli@arm.com>

> Cc: Juri Lelli <juri.lelli@arm.com>
> Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
> ---
> v1 -> v2:
>  * move sched_dl_global_constraints before sched_rt_global_constraints,
>    and change the name of the former to sched_dl_global_validate().
> 
>  kernel/sched/core.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 97fe79c..e884909 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -7815,7 +7815,7 @@ static int sched_rt_global_constraints(void)
>  }
>  #endif /* CONFIG_RT_GROUP_SCHED */
>  
> -static int sched_dl_global_constraints(void)
> +static int sched_dl_global_validate(void)
>  {
>  	u64 runtime = global_rt_runtime();
>  	u64 period = global_rt_period();
> @@ -7916,11 +7916,11 @@ int sched_rt_handler(struct ctl_table *table, int write,
>  		if (ret)
>  			goto undo;
>  
> -		ret = sched_rt_global_constraints();
> +		ret = sched_dl_global_validate();
>  		if (ret)
>  			goto undo;
>  
> -		ret = sched_dl_global_constraints();
> +		ret = sched_rt_global_constraints();
>  		if (ret)
>  			goto undo;
>  
> 


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH RESEND v2] sched/deadline: fix rt runtime corrupt when dl refuse a smaller bandwidth
  2015-03-17  2:25 ` Wanpeng Li
@ 2015-03-17  8:09   ` Ingo Molnar
  0 siblings, 0 replies; 5+ messages in thread
From: Ingo Molnar @ 2015-03-17  8:09 UTC (permalink / raw)
  To: Wanpeng Li; +Cc: Ingo Molnar, Peter Zijlstra, Juri Lelli, linux-kernel


* Wanpeng Li <wanpeng.li@linux.intel.com> wrote:

> Ping Ingo, ;-)

Same observation as for the other patch: the changelog is not very 
readable to me, it has various spelling mistakes that make it hard to 
read. Seems like Juri acked the patch, mind asking him to fix the 
changelog to be readable?

Thanks,

	Ingo

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH RESEND v2] sched/deadline: fix rt runtime corrupt when dl refuse a smaller bandwidth
  2015-03-13  7:28 Wanpeng Li
@ 2015-03-17  2:25 ` Wanpeng Li
  2015-03-17  8:09   ` Ingo Molnar
  0 siblings, 1 reply; 5+ messages in thread
From: Wanpeng Li @ 2015-03-17  2:25 UTC (permalink / raw)
  To: Ingo Molnar; +Cc: Peter Zijlstra, Juri Lelli, linux-kernel, Wanpeng Li

Ping Ingo, ;-)
On Fri, Mar 13, 2015 at 03:28:00PM +0800, Wanpeng Li wrote:
>Dl class will refuse the bandwidth being set to some value smaller
>than the currently allocated bandwidth in any of the root_domains
>through sched_rt_runtime_us and sched_rt_period_us. RT runtime will
>be set according to sched_rt_runtime_us before dl class verify if
>the new bandwidth is suitable in the case of !CONFIG_RT_GROUP_SCHED.
>
>However, rt runtime will be corrupt if dl refuse the new bandwidth
>since there is no undo to reset the rt runtime to the old value.
>
>This patch fix it by verifying new bandwidth for deadline in advance.
>
>Acked-by: Juri Lelli <juri.lelli@arm.com>
>Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
>---
> kernel/sched/core.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
>diff --git a/kernel/sched/core.c b/kernel/sched/core.c
>index 97fe79c..e884909 100644
>--- a/kernel/sched/core.c
>+++ b/kernel/sched/core.c
>@@ -7815,7 +7815,7 @@ static int sched_rt_global_constraints(void)
> }
> #endif /* CONFIG_RT_GROUP_SCHED */
> 
>-static int sched_dl_global_constraints(void)
>+static int sched_dl_global_validate(void)
> {
> 	u64 runtime = global_rt_runtime();
> 	u64 period = global_rt_period();
>@@ -7916,11 +7916,11 @@ int sched_rt_handler(struct ctl_table *table, int write,
> 		if (ret)
> 			goto undo;
> 
>-		ret = sched_rt_global_constraints();
>+		ret = sched_dl_global_validate();
> 		if (ret)
> 			goto undo;
> 
>-		ret = sched_dl_global_constraints();
>+		ret = sched_rt_global_constraints();
> 		if (ret)
> 			goto undo;
> 
>-- 
>1.9.1

^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH RESEND v2] sched/deadline: fix rt runtime corrupt when dl refuse a smaller bandwidth
@ 2015-03-13  7:28 Wanpeng Li
  2015-03-17  2:25 ` Wanpeng Li
  0 siblings, 1 reply; 5+ messages in thread
From: Wanpeng Li @ 2015-03-13  7:28 UTC (permalink / raw)
  To: Ingo Molnar, Peter Zijlstra; +Cc: Juri Lelli, linux-kernel, Wanpeng Li

Dl class will refuse the bandwidth being set to some value smaller
than the currently allocated bandwidth in any of the root_domains
through sched_rt_runtime_us and sched_rt_period_us. RT runtime will
be set according to sched_rt_runtime_us before dl class verify if
the new bandwidth is suitable in the case of !CONFIG_RT_GROUP_SCHED.

However, rt runtime will be corrupt if dl refuse the new bandwidth
since there is no undo to reset the rt runtime to the old value.

This patch fix it by verifying new bandwidth for deadline in advance.

Acked-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
---
 kernel/sched/core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 97fe79c..e884909 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7815,7 +7815,7 @@ static int sched_rt_global_constraints(void)
 }
 #endif /* CONFIG_RT_GROUP_SCHED */
 
-static int sched_dl_global_constraints(void)
+static int sched_dl_global_validate(void)
 {
 	u64 runtime = global_rt_runtime();
 	u64 period = global_rt_period();
@@ -7916,11 +7916,11 @@ int sched_rt_handler(struct ctl_table *table, int write,
 		if (ret)
 			goto undo;
 
-		ret = sched_rt_global_constraints();
+		ret = sched_dl_global_validate();
 		if (ret)
 			goto undo;
 
-		ret = sched_dl_global_constraints();
+		ret = sched_rt_global_constraints();
 		if (ret)
 			goto undo;
 
-- 
1.9.1


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2015-03-17  8:09 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-02-25  4:37 [PATCH RESEND v2] sched/deadline: fix rt runtime corrupt when dl refuse a smaller bandwidth Wanpeng Li
2015-02-26  9:55 ` Juri Lelli
2015-03-13  7:28 Wanpeng Li
2015-03-17  2:25 ` Wanpeng Li
2015-03-17  8:09   ` Ingo Molnar

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).