[PATCH] Add Documentation for FAIR_USER_SCHED sysfs files

[PATCH] Add Documentation for FAIR_USER_SCHED sysfs files

[Dhaval Giani]

This patch adds documentation about /sys/kernel/uids/<uid>/cpu_share
to Documentation/ABI.

Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>

---
 Documentation/ABI/testing/sysfs-kernel-uids |   10 ++++++++++
 1 files changed, 10 insertions(+)

Index: current/Documentation/ABI/testing/sysfs-kernel-uids
===================================================================
--- /dev/null
+++ current/Documentation/ABI/testing/sysfs-kernel-uids
@@ -0,0 +1,10 @@
+What:		/sys/kernel/uids/<uid>/cpu_shares
+Date:		December 2007
+Contact:	Dhaval Giani <dhaval@linux.vnet.ibm.com>
+		Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
+Description:
+		The /sys/kernel/uids/<uid>/cpu_shares tunable is used
+		to set the cpu bandwidth a user is allowed. This is a
+		propotional value. What that means is that if there
+		are two users logged in, each with shares 1024, they
+		will get equal CPU bandwidth.
-- 
regards,
Dhaval

Re: [PATCH] Add Documentation for FAIR_USER_SCHED sysfs files

[Greg KH]

On Wed, Dec 12, 2007 at 08:08:36AM +0530, Dhaval Giani wrote:
> 
> This patch adds documentation about /sys/kernel/uids/<uid>/cpu_share
> to Documentation/ABI.
> 
> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
> 
> ---
>  Documentation/ABI/testing/sysfs-kernel-uids |   10 ++++++++++
>  1 files changed, 10 insertions(+)
> 
> Index: current/Documentation/ABI/testing/sysfs-kernel-uids
> ===================================================================
> --- /dev/null
> +++ current/Documentation/ABI/testing/sysfs-kernel-uids
> @@ -0,0 +1,10 @@
> +What:		/sys/kernel/uids/<uid>/cpu_shares
> +Date:		December 2007
> +Contact:	Dhaval Giani <dhaval@linux.vnet.ibm.com>
> +		Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
> +Description:
> +		The /sys/kernel/uids/<uid>/cpu_shares tunable is used
> +		to set the cpu bandwidth a user is allowed. This is a
> +		propotional value. What that means is that if there
> +		are two users logged in, each with shares 1024, they
> +		will get equal CPU bandwidth.

Hm, how about describing the units here?  Can you put "10" in each file
and everyone will get the same share?  100?  1?  1024 seems like an odd
"share" number.  Unless there is some other document you wish to refer
people to do help describe these values?

thanks,

greg k-h

Re: [PATCH] Add Documentation for FAIR_USER_SCHED sysfs files

[Dhaval Giani]

On Tue, Dec 11, 2007 at 09:35:56PM -0800, Greg KH wrote:
> On Wed, Dec 12, 2007 at 08:08:36AM +0530, Dhaval Giani wrote:
> > 
> > This patch adds documentation about /sys/kernel/uids/<uid>/cpu_share
> > to Documentation/ABI.
> > 
> > Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
> > 
> > ---
> >  Documentation/ABI/testing/sysfs-kernel-uids |   10 ++++++++++
> >  1 files changed, 10 insertions(+)
> > 
> > Index: current/Documentation/ABI/testing/sysfs-kernel-uids
> > ===================================================================
> > --- /dev/null
> > +++ current/Documentation/ABI/testing/sysfs-kernel-uids
> > @@ -0,0 +1,10 @@
> > +What:		/sys/kernel/uids/<uid>/cpu_shares
> > +Date:		December 2007
> > +Contact:	Dhaval Giani <dhaval@linux.vnet.ibm.com>
> > +		Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
> > +Description:
> > +		The /sys/kernel/uids/<uid>/cpu_shares tunable is used
> > +		to set the cpu bandwidth a user is allowed. This is a
> > +		propotional value. What that means is that if there
> > +		are two users logged in, each with shares 1024, they
> > +		will get equal CPU bandwidth.
> 
> Hm, how about describing the units here?  Can you put "10" in each file
> and everyone will get the same share?  100?  1?  1024 seems like an odd
> "share" number.  Unless there is some other document you wish to refer
> people to do help describe these values?
> 

It is proportional. That is, if two users have same value for shares,
they will get equal bandwidth on the CPU. If they are in the ratio 1:2,
then they will share it in that ratio. I've updated the patch for this.
Hope it is clearer.

Thanks,
--

This patch adds documentation about /sys/kernel/uids/<uid>/cpu_share
to Documentation/ABI.

Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>

---
 Documentation/ABI/testing/sysfs-kernel-uids |   14 ++++++++++++++
 1 files changed, 14 insertions(+)

Index: current/Documentation/ABI/testing/sysfs-kernel-uids
===================================================================
--- /dev/null
+++ current/Documentation/ABI/testing/sysfs-kernel-uids
@@ -0,0 +1,14 @@
+What:		/sys/kernel/uids/<uid>/cpu_shares
+Date:		December 2007
+Contact:	Dhaval Giani <dhaval@linux.vnet.ibm.com>
+		Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
+Description:
+		The /sys/kernel/uids/<uid>/cpu_shares tunable is used
+		to set the cpu bandwidth a user is allowed. This is a
+		propotional value. What that means is that if there
+		are two users logged in, each with an equal number of
+		shares, then they will get equal CPU bandwidth. Another
+		example would be, if User A has shares = 1024 and user
+		B has shares = 2048, User B will get twice the CPU
+		bandwidth user A will. For more details refer
+		Documentation/sched-design-CFS.txt

-- 
regards,
Dhaval

Re: [PATCH] Add Documentation for FAIR_USER_SCHED sysfs files

[Ingo Molnar]

* Dhaval Giani <dhaval@linux.vnet.ibm.com> wrote:

> > Hm, how about describing the units here?  Can you put "10" in each 
> > file and everyone will get the same share?  100?  1?  1024 seems 
> > like an odd "share" number.  Unless there is some other document you 
> > wish to refer people to do help describe these values?
> 
> It is proportional. That is, if two users have same value for shares, 
> they will get equal bandwidth on the CPU. If they are in the ratio 
> 1:2, then they will share it in that ratio. I've updated the patch for 
> this. Hope it is clearer.

thanks, applied.

	Ingo

Re: [PATCH] Add Documentation for FAIR_USER_SCHED sysfs files

[Ingo Molnar]

* Ingo Molnar <mingo@elte.hu> wrote:

> 
> * Dhaval Giani <dhaval@linux.vnet.ibm.com> wrote:
> 
> > > Hm, how about describing the units here?  Can you put "10" in each 
> > > file and everyone will get the same share?  100?  1?  1024 seems 
> > > like an odd "share" number.  Unless there is some other document you 
> > > wish to refer people to do help describe these values?
> > 
> > It is proportional. That is, if two users have same value for shares, 
> > they will get equal bandwidth on the CPU. If they are in the ratio 
> > 1:2, then they will share it in that ratio. I've updated the patch for 
> > this. Hope it is clearer.
> 
> thanks, applied.

unless Greg wants to push this via the sysfs git tree?

	Ingo

Re: [PATCH] Add Documentation for FAIR_USER_SCHED sysfs files

[Greg KH]

On Wed, Dec 12, 2007 at 11:16:45AM +0100, Ingo Molnar wrote:
> 
> * Ingo Molnar <mingo@elte.hu> wrote:
> 
> > 
> > * Dhaval Giani <dhaval@linux.vnet.ibm.com> wrote:
> > 
> > > > Hm, how about describing the units here?  Can you put "10" in each 
> > > > file and everyone will get the same share?  100?  1?  1024 seems 
> > > > like an odd "share" number.  Unless there is some other document you 
> > > > wish to refer people to do help describe these values?
> > > 
> > > It is proportional. That is, if two users have same value for shares, 
> > > they will get equal bandwidth on the CPU. If they are in the ratio 
> > > 1:2, then they will share it in that ratio. I've updated the patch for 
> > > this. Hope it is clearer.
> > 
> > thanks, applied.
> 
> unless Greg wants to push this via the sysfs git tree?

Sure, I can do that, what's one more patch in my tree?  :)

thanks,

greg k-h

patch add-documentation-for-fair_user_sched-sysfs-files.patch added to gregkh-2.6 tree

[gregkh]

This is a note to let you know that I've just added the patch titled

     Subject: Add Documentation for FAIR_USER_SCHED sysfs files

to my gregkh-2.6 tree.  Its filename is

     add-documentation-for-fair_user_sched-sysfs-files.patch

This tree can be found at 
    http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/


>From dhaval@linux.vnet.ibm.com Tue Dec 11 21:51:17 2007
From: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Date: Wed, 12 Dec 2007 11:18:59 +0530
Subject: Add Documentation for FAIR_USER_SCHED sysfs files
To: Greg KH <gregkh@suse.de>
Cc: lkml <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>, Andrew Morton <akpm@linux-foundation.org>, Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>, Balbir Singh <balbir@in.ibm.com>
Message-ID: <20071212054859.GC1486@linux.vnet.ibm.com>
Content-Disposition: inline

This patch adds documentation about /sys/kernel/uids/<uid>/cpu_share
to Documentation/ABI.

Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 Documentation/ABI/testing/sysfs-kernel-uids |   14 ++++++++++++++
 1 file changed, 14 insertions(+)

--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-uids
@@ -0,0 +1,14 @@
+What:		/sys/kernel/uids/<uid>/cpu_shares
+Date:		December 2007
+Contact:	Dhaval Giani <dhaval@linux.vnet.ibm.com>
+		Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
+Description:
+		The /sys/kernel/uids/<uid>/cpu_shares tunable is used
+		to set the cpu bandwidth a user is allowed. This is a
+		propotional value. What that means is that if there
+		are two users logged in, each with an equal number of
+		shares, then they will get equal CPU bandwidth. Another
+		example would be, if User A has shares = 1024 and user
+		B has shares = 2048, User B will get twice the CPU
+		bandwidth user A will. For more details refer
+		Documentation/sched-design-CFS.txt


Patches currently in gregkh-2.6 which might be from dhaval@linux.vnet.ibm.com are

driver/struct-user_info-sysfs.patch
driver/add-documentation-for-fair_user_sched-sysfs-files.patch