[PATCH v2 0/3] cgroup, docs: cpu controller interaction with various scheduling policies

[PATCH v2 0/3] cgroup, docs: cpu controller interaction with various scheduling policies

[Shashank Balaji via B4 Relay]

The cgroup v2 cpu controller interface files interact with processes
differently based on their scheduling policy and the underlying
scheduler used (fair-class vs. BPF scheduler). This patchset
documents these differences.

This is related to the previous patchset titled "cgroup, docs: Clarify
interaction of RT processes with cgroup v2 cpu controller"
(https://lore.kernel.org/all/20250305-rt-and-cpu-controller-doc-v1-0-7b6a6f5ff43d@sony.com/),
which focused solely on RT processes. The current patchset incorporates
the previous feedback and expands on the scope of scheduling policies.

Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
---
Shashank Balaji (3):
      cgroup, docs: be specific about bandwidth control of rt processes
      sched_ext, docs: add label
      cgroup, docs: cpu controller interaction with various scheduling policies

 Documentation/admin-guide/cgroup-v2.rst | 100 ++++++++++++++++++++++++--------
 Documentation/scheduler/sched-ext.rst   |   2 +
 2 files changed, 78 insertions(+), 24 deletions(-)
---
base-commit: 036ee8a17bd046d7a350de0aae152307a061cc46
change-id: 20250226-rt-and-cpu-controller-doc-8a8aac572f3e

Best regards,
-- 
Shashank Balaji <shashank.mahadasyam@sony.com>

[PATCH v2 1/3] cgroup, docs: be specific about bandwidth control of rt processes

[Shashank Balaji via B4 Relay]

From: Shashank Balaji <shashank.mahadasyam@sony.com>

Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
---
 Documentation/admin-guide/cgroup-v2.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 1a16ce68a4d7f6f8c9070be89c4975dbfa79077e..3b3685736fe9b12e96a273248dfb4a8c62a4b698 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1076,7 +1076,7 @@ cpufreq governor about the minimum desired frequency which should always be
 provided by a CPU, as well as the maximum desired frequency, which should not
 be exceeded by a CPU.
 
-WARNING: cgroup2 cpu controller doesn't yet fully support the control of
+WARNING: cgroup2 cpu controller doesn't yet support the (bandwidth) control of
 realtime processes. For a kernel built with the CONFIG_RT_GROUP_SCHED option
 enabled for group scheduling of realtime processes, the cpu controller can only
 be enabled when all RT processes are in the root cgroup. Be aware that system

-- 
2.43.0

[PATCH v2 2/3] sched_ext, docs: add label

[Shashank Balaji via B4 Relay]

From: Shashank Balaji <shashank.mahadasyam@sony.com>

Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
---
 Documentation/scheduler/sched-ext.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/scheduler/sched-ext.rst b/Documentation/scheduler/sched-ext.rst
index 0b2654e2164b8e6139db19fc8b68e6c5c289503d..03f9e63a7b2aa10567366ff3e1a0cfc05b43e05a 100644
--- a/Documentation/scheduler/sched-ext.rst
+++ b/Documentation/scheduler/sched-ext.rst
@@ -1,3 +1,5 @@
+.. _sched-ext:
+
 ==========================
 Extensible Scheduler Class
 ==========================

-- 
2.43.0

[PATCH v2 3/3] cgroup, docs: cpu controller interaction with various scheduling policies

[Shashank Balaji via B4 Relay]

From: Shashank Balaji <shashank.mahadasyam@sony.com>

The cpu controller interface files account for or affect processes
differently based on their scheduling policy, and the underlying
scheduler used (fair-class vs. BPF scheduler). Document these
differences

Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
---
 Documentation/admin-guide/cgroup-v2.rst | 98 +++++++++++++++++++++++++--------
 1 file changed, 75 insertions(+), 23 deletions(-)

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 3b3685736fe9b12e96a273248dfb4a8c62a4b698..0f79bf42a3e3b2fcbe6409f9e182ba9de1fbb79c 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1095,19 +1095,50 @@ realtime processes irrespective of CONFIG_RT_GROUP_SCHED.
 CPU Interface Files
 ~~~~~~~~~~~~~~~~~~~
 
-All time durations are in microseconds.
+The interaction of a process with the cpu controller depends on its scheduling
+policy. We have the following scheduling policies: ``SCHED_IDLE``, ``SCHED_BATCH``,
+``SCHED_OTHER``, ``SCHED_EXT`` (if ``CONFIG_SCHED_CLASS_EXT`` is enabled), ``SCHED_FIFO``,
+``SCHED_RR``, and ``SCHED_DEADLINE``. ``SCHED_{IDLE,BATCH,OTHER,EXT}`` can be scheduled
+either by the fair-class scheduler or by a BPF scheduler::
+
+    CONFIG_SCHED_CLASS_EXT
+    ├─ Disabled
+    |   └─ SCHED_{IDLE,BATCH,OTHER} -> fair-class scheduler
+    └─ Enabled
+        ├─ BPF scheduler disabled
+        |   └─ SCHED_{IDLE,BATCH,OTHER,EXT} -> fair-class scheduler
+        ├─ BPF scheduler without SCX_OPS_SWITCH_PARTIAL enabled
+        |   └─ SCHED_{IDLE,BATCH,OTHER,EXT} -> BPF scheduler
+        └─ BPF scheduler with SCX_OPS_SWITCH_PARTIAL enabled
+            ├─ SCHED_{IDLE,BATCH,OTHER} -> fair-class scheduler
+            └─ SCHED_EXT -> BPF scheduler
+
+For more details on ``SCHED_EXT``, check out :ref:`Documentation/scheduler/sched-ext.rst. <sched-ext>`
+From the point of view of the cpu controller, processes can be categorized as
+follows:
+
+* Processes under the fair-class scheduler
+* Processes under a BPF scheduler with the ``cgroup_set_weight`` callback
+* Everything else: ``SCHED_{FIFO,RR,DEADLINE}`` and processes under a BPF scheduler
+  without the ``cgroup_set_weight`` callback
+
+Note that the ``cgroup_*`` family of callbacks require ``CONFIG_EXT_GROUP_SCHED``
+to be enabled. For each of the following interface files, the above categories
+will be referred to. All time durations are in microseconds.
 
   cpu.stat
 	A read-only flat-keyed file.
 	This file exists whether the controller is enabled or not.
 
-	It always reports the following three stats:
+	It always reports the following three stats, which account for all the
+	processes in the cgroup:
 
 	- usage_usec
 	- user_usec
 	- system_usec
 
-	and the following five when the controller is enabled:
+	and the following five when the controller is enabled, which account for
+	only the processes under the fair-class scheduler:
 
 	- nr_periods
 	- nr_throttled
@@ -1125,6 +1156,10 @@ All time durations are in microseconds.
 	If the cgroup has been configured to be SCHED_IDLE (cpu.idle = 1),
 	then the weight will show as a 0.
 
+	This file affects only processes under the fair-class scheduler and a BPF
+	scheduler with the ``cgroup_set_weight`` callback depending on what the
+	callback actually does.
+
   cpu.weight.nice
 	A read-write single value file which exists on non-root
 	cgroups.  The default is "0".
@@ -1137,6 +1172,10 @@ All time durations are in microseconds.
 	granularity is coarser for the nice values, the read value is
 	the closest approximation of the current weight.
 
+	This file affects only processes under the fair-class scheduler and a BPF
+	scheduler with the ``cgroup_set_weight`` callback depending on what the
+	callback actually does.
+
   cpu.max
 	A read-write two value file which exists on non-root cgroups.
 	The default is "max 100000".
@@ -1149,43 +1188,56 @@ All time durations are in microseconds.
 	$PERIOD duration.  "max" for $MAX indicates no limit.  If only
 	one number is written, $MAX is updated.
 
+	This file affects only processes under the fair-class scheduler.
+
   cpu.max.burst
 	A read-write single value file which exists on non-root
 	cgroups.  The default is "0".
 
 	The burst in the range [0, $MAX].
 
+	This file affects only processes under the fair-class scheduler.
+
   cpu.pressure
 	A read-write nested-keyed file.
 
-	Shows pressure stall information for CPU. See
-	:ref:`Documentation/accounting/psi.rst <psi>` for details.
+	Shows pressure stall information for CPU, including the contribution of
+	realtime processes. See :ref:`Documentation/accounting/psi.rst <psi>`
+	for details.
+
+	This file accounts for all the processes in the cgroup.
 
   cpu.uclamp.min
-        A read-write single value file which exists on non-root cgroups.
-        The default is "0", i.e. no utilization boosting.
+	A read-write single value file which exists on non-root cgroups.
+	The default is "0", i.e. no utilization boosting.
 
-        The requested minimum utilization (protection) as a percentage
-        rational number, e.g. 12.34 for 12.34%.
+	The requested minimum utilization (protection) as a percentage
+	rational number, e.g. 12.34 for 12.34%.
 
-        This interface allows reading and setting minimum utilization clamp
-        values similar to the sched_setattr(2). This minimum utilization
-        value is used to clamp the task specific minimum utilization clamp.
+	This interface allows reading and setting minimum utilization clamp
+	values similar to the sched_setattr(2). This minimum utilization
+	value is used to clamp the task specific minimum utilization clamp,
+	including those of realtime processes.
 
-        The requested minimum utilization (protection) is always capped by
-        the current value for the maximum utilization (limit), i.e.
-        `cpu.uclamp.max`.
+	The requested minimum utilization (protection) is always capped by
+	the current value for the maximum utilization (limit), i.e.
+	`cpu.uclamp.max`.
+
+	This file affects all the processes in the cgroup.
 
   cpu.uclamp.max
-        A read-write single value file which exists on non-root cgroups.
-        The default is "max". i.e. no utilization capping
+	A read-write single value file which exists on non-root cgroups.
+	The default is "max". i.e. no utilization capping
 
-        The requested maximum utilization (limit) as a percentage rational
-        number, e.g. 98.76 for 98.76%.
+	The requested maximum utilization (limit) as a percentage rational
+	number, e.g. 98.76 for 98.76%.
 
-        This interface allows reading and setting maximum utilization clamp
-        values similar to the sched_setattr(2). This maximum utilization
-        value is used to clamp the task specific maximum utilization clamp.
+	This interface allows reading and setting maximum utilization clamp
+	values similar to the sched_setattr(2). This maximum utilization
+	value is used to clamp the task specific maximum utilization clamp,
+	including those of realtime processes.
+
+	This file affects all the processes in the cgroup.
 
   cpu.idle
 	A read-write single value file which exists on non-root cgroups.
@@ -1197,7 +1249,7 @@ All time durations are in microseconds.
 	own relative priorities, but the cgroup itself will be treated as
 	very low priority relative to its peers.
 
-
+	This file affects only processes under the fair-class scheduler.
 
 Memory
 ------

-- 
2.43.0

Re: [PATCH v2 1/3] cgroup, docs: be specific about bandwidth control of rt processes

[Tejun Heo]

On Tue, May 20, 2025 at 11:07:45PM +0900, Shashank Balaji via B4 Relay wrote:
> From: Shashank Balaji <shashank.mahadasyam@sony.com>
> 
> Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
> ---
>  Documentation/admin-guide/cgroup-v2.rst | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
> index 1a16ce68a4d7f6f8c9070be89c4975dbfa79077e..3b3685736fe9b12e96a273248dfb4a8c62a4b698 100644
> --- a/Documentation/admin-guide/cgroup-v2.rst
> +++ b/Documentation/admin-guide/cgroup-v2.rst
> @@ -1076,7 +1076,7 @@ cpufreq governor about the minimum desired frequency which should always be
>  provided by a CPU, as well as the maximum desired frequency, which should not
>  be exceeded by a CPU.
>  
> -WARNING: cgroup2 cpu controller doesn't yet fully support the control of
> +WARNING: cgroup2 cpu controller doesn't yet support the (bandwidth) control of

This reads weird to me. Without the () part, it becomes "doesn't yet support
the control of". Maybe rephrase it a bit more?

Thanks.

-- 
tejun

Re: [PATCH v2 3/3] cgroup, docs: cpu controller interaction with various scheduling policies

[Tejun Heo]

Hello,

On Tue, May 20, 2025 at 11:07:47PM +0900, Shashank Balaji via B4 Relay wrote:
...
> +The interaction of a process with the cpu controller depends on its scheduling
> +policy. We have the following scheduling policies: ``SCHED_IDLE``, ``SCHED_BATCH``,
> +``SCHED_OTHER``, ``SCHED_EXT`` (if ``CONFIG_SCHED_CLASS_EXT`` is enabled), ``SCHED_FIFO``,
> +``SCHED_RR``, and ``SCHED_DEADLINE``. ``SCHED_{IDLE,BATCH,OTHER,EXT}`` can be scheduled
> +either by the fair-class scheduler or by a BPF scheduler::
> +
> +    CONFIG_SCHED_CLASS_EXT
> +    ├─ Disabled
> +    |   └─ SCHED_{IDLE,BATCH,OTHER} -> fair-class scheduler
> +    └─ Enabled
> +        ├─ BPF scheduler disabled
> +        |   └─ SCHED_{IDLE,BATCH,OTHER,EXT} -> fair-class scheduler
> +        ├─ BPF scheduler without SCX_OPS_SWITCH_PARTIAL enabled
> +        |   └─ SCHED_{IDLE,BATCH,OTHER,EXT} -> BPF scheduler
> +        └─ BPF scheduler with SCX_OPS_SWITCH_PARTIAL enabled
> +            ├─ SCHED_{IDLE,BATCH,OTHER} -> fair-class scheduler
> +            └─ SCHED_EXT -> BPF scheduler
> +
> +For more details on ``SCHED_EXT``, check out :ref:`Documentation/scheduler/sched-ext.rst. <sched-ext>`
> +From the point of view of the cpu controller, processes can be categorized as
> +follows:
> +
> +* Processes under the fair-class scheduler
> +* Processes under a BPF scheduler with the ``cgroup_set_weight`` callback
> +* Everything else: ``SCHED_{FIFO,RR,DEADLINE}`` and processes under a BPF scheduler
> +  without the ``cgroup_set_weight`` callback
> +
> +Note that the ``cgroup_*`` family of callbacks require ``CONFIG_EXT_GROUP_SCHED``
> +to be enabled. For each of the following interface files, the above categories
> +will be referred to. All time durations are in microseconds.

Can we document the above in sched_ext documentation and point to it from
here? Documenting sched_ext details here seems a bit out of place and prone
to becoming stale over time.

...
>    cpu.uclamp.min
> -        A read-write single value file which exists on non-root cgroups.
> -        The default is "0", i.e. no utilization boosting.
> +	A read-write single value file which exists on non-root cgroups.
> +	The default is "0", i.e. no utilization boosting.

Can you please separate out indentation changes to a separate patch? These
usually make reviewing tricky.

Thanks.

-- 
tejun

Re: [PATCH v2 2/3] sched_ext, docs: add label

[Tejun Heo]

On Tue, May 20, 2025 at 11:07:46PM +0900, Shashank Balaji via B4 Relay wrote:
> From: Shashank Balaji <shashank.mahadasyam@sony.com>
> 
> Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>

Applied to sched_ext/for-6.16.

Thanks.

-- 
tejun

Re: [PATCH v2 1/3] cgroup, docs: be specific about bandwidth control of rt processes

[Shashank.Mahadasyam]

Hi Tejun,

On 21 May 2025 5:11, Tejun Heo wrote:
> > -WARNING: cgroup2 cpu controller doesn't yet fully support the control of
> > +WARNING: cgroup2 cpu controller doesn't yet support the (bandwidth) control of
>
> This reads weird to me. Without the () part, it becomes "doesn't yet support
> the control of". Maybe rephrase it a bit more?

I'm not sure how to rephrase it. It sounds fine to me 😅 Moreover, "doesn't yet support the control of" was the wording when the warning paragraph on RT_GROUP_SCHED was added in commit c2f31b79 (cgroup: add warning about RT not being supported on cgroup2). Would removing the parentheses, making it "doesn't yet support the bandwidth control of", sound better?

Thank you

Regards,
Shashank

________________________________________
From: Tejun Heo <tj@kernel.org>
Sent: 21 May 2025 5:11
To: Mahadasyam, Shashank (SGC)
Cc: Johannes Weiner; Michal Koutný; Jonathan Corbet; cgroups@vger.kernel.org; linux-doc@vger.kernel.org; linux-kernel@vger.kernel.org; Takumi, Shinya (SGC)
Subject: Re: [PATCH v2 1/3] cgroup, docs: be specific about bandwidth control of rt processes

On Tue, May 20, 2025 at 11: 07: 45PM +0900, Shashank Balaji via B4 Relay wrote: > From: Shashank Balaji <shashank. mahadasyam@ sony. com> > > Signed-off-by: Shashank Balaji <shashank. mahadasyam@ sony. com> > --- > Documentation/admin-guide/cgroup-v2. rst


On Tue, May 20, 2025 at 11:07:45PM +0900, Shashank Balaji via B4 Relay wrote:
> From: Shashank Balaji <shashank.mahadasyam@sony.com>
>
> Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
> ---
>  Documentation/admin-guide/cgroup-v2.rst | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
> index 1a16ce68a4d7f6f8c9070be89c4975dbfa79077e..3b3685736fe9b12e96a273248dfb4a8c62a4b698 100644
> --- a/Documentation/admin-guide/cgroup-v2.rst
> +++ b/Documentation/admin-guide/cgroup-v2.rst
> @@ -1076,7 +1076,7 @@ cpufreq governor about the minimum desired frequency which should always be
>  provided by a CPU, as well as the maximum desired frequency, which should not
>  be exceeded by a CPU.
>
> -WARNING: cgroup2 cpu controller doesn't yet fully support the control of
> +WARNING: cgroup2 cpu controller doesn't yet support the (bandwidth) control of

This reads weird to me. Without the () part, it becomes "doesn't yet support
the control of". Maybe rephrase it a bit more?

Thanks.

--
tejun

Re: [PATCH v2 3/3] cgroup, docs: cpu controller interaction with various scheduling policies

[Shashank Balaji]

Hi Tejun,

On Tue, May 20, 2025 at 10:16:38AM -1000, Tejun Heo wrote:
> Hello,
> 
> On Tue, May 20, 2025 at 11:07:47PM +0900, Shashank Balaji via B4 Relay wrote:
> ...
> > +The interaction of a process with the cpu controller depends on its scheduling
> > +policy. We have the following scheduling policies: ``SCHED_IDLE``, ``SCHED_BATCH``,
> > +``SCHED_OTHER``, ``SCHED_EXT`` (if ``CONFIG_SCHED_CLASS_EXT`` is enabled), ``SCHED_FIFO``,
> > +``SCHED_RR``, and ``SCHED_DEADLINE``. ``SCHED_{IDLE,BATCH,OTHER,EXT}`` can be scheduled
> > +either by the fair-class scheduler or by a BPF scheduler::
> > +
> > +    CONFIG_SCHED_CLASS_EXT
> > +    ├─ Disabled
> > +    |   └─ SCHED_{IDLE,BATCH,OTHER} -> fair-class scheduler
> > +    └─ Enabled
> > +        ├─ BPF scheduler disabled
> > +        |   └─ SCHED_{IDLE,BATCH,OTHER,EXT} -> fair-class scheduler
> > +        ├─ BPF scheduler without SCX_OPS_SWITCH_PARTIAL enabled
> > +        |   └─ SCHED_{IDLE,BATCH,OTHER,EXT} -> BPF scheduler
> > +        └─ BPF scheduler with SCX_OPS_SWITCH_PARTIAL enabled
> > +            ├─ SCHED_{IDLE,BATCH,OTHER} -> fair-class scheduler
> > +            └─ SCHED_EXT -> BPF scheduler
> > +
> > +For more details on ``SCHED_EXT``, check out :ref:`Documentation/scheduler/sched-ext.rst. <sched-ext>`
> > +From the point of view of the cpu controller, processes can be categorized as
> > +follows:
> > +
> > +* Processes under the fair-class scheduler
> > +* Processes under a BPF scheduler with the ``cgroup_set_weight`` callback
> > +* Everything else: ``SCHED_{FIFO,RR,DEADLINE}`` and processes under a BPF scheduler
> > +  without the ``cgroup_set_weight`` callback
> > +
> > +Note that the ``cgroup_*`` family of callbacks require ``CONFIG_EXT_GROUP_SCHED``
> > +to be enabled. For each of the following interface files, the above categories
> > +will be referred to. All time durations are in microseconds.
> 
> Can we document the above in sched_ext documentation and point to it from
> here? Documenting sched_ext details here seems a bit out of place and prone
> to becoming stale over time.

Got it. Apart from that, is the content alright? 

> Can you please separate out indentation changes to a separate patch? These
> usually make reviewing tricky.

Got it.

Thank you

Regards,
Shashank

PS: Apologies for any malformed emails. I finally managed to switch from Outlook
to mutt.

Re: [PATCH v2 1/3] cgroup, docs: be specific about bandwidth control of rt processes

[Tejun Heo]

Hello,

On Wed, May 21, 2025 at 01:14:53AM +0000, Shashank.Mahadasyam@sony.com wrote:
> Hi Tejun,
> 
> On 21 May 2025 5:11, Tejun Heo wrote:
> > > -WARNING: cgroup2 cpu controller doesn't yet fully support the control of
> > > +WARNING: cgroup2 cpu controller doesn't yet support the (bandwidth) control of
> >
> > This reads weird to me. Without the () part, it becomes "doesn't yet support
> > the control of". Maybe rephrase it a bit more?
> 
> I'm not sure how to rephrase it. It sounds fine to me 😅 Moreover, "doesn't
> yet support the control of" was the wording when the warning paragraph on
> RT_GROUP_SCHED was added in commit c2f31b79 (cgroup: add warning about RT
> not being supported on cgroup2). Would removing the parentheses, making it
> "doesn't yet support the bandwidth control of", sound better?

You're right. I was thinking about sched_ext not RT. Lemme apply the patch
as-is.

Thanks.

-- 
tejun

Re: [PATCH v2 1/3] cgroup, docs: be specific about bandwidth control of rt processes

[Tejun Heo]

On Tue, May 20, 2025 at 11:07:45PM +0900, Shashank Balaji via B4 Relay wrote:
> From: Shashank Balaji <shashank.mahadasyam@sony.com>
> 
> Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>

Applied to cgroup/for-6.16.

Thanks.

-- 
tejun

Re: [PATCH v2 3/3] cgroup, docs: cpu controller interaction with various scheduling policies

[Tejun Heo]

On Wed, May 21, 2025 at 04:49:43PM +0900, Shashank Balaji wrote:
> > > +Note that the ``cgroup_*`` family of callbacks require ``CONFIG_EXT_GROUP_SCHED``

CONFIG_EXT_GROUP_SCHED is auto-enabled if CONFIG_SCHED_CLASS_EXT and
CONFIG_CGROUP_SCHED are enabled, so no need to mention it explicitly.

> > > +to be enabled. For each of the following interface files, the above categories
> > > +will be referred to. All time durations are in microseconds.
> > 
> > Can we document the above in sched_ext documentation and point to it from
> > here? Documenting sched_ext details here seems a bit out of place and prone
> > to becoming stale over time.
> 
> Got it. Apart from that, is the content alright? 

Other than the above, yeah, looks correct to me.

Thanks.

-- 
tejun