[PATCH] Doc: admin-guide: Add entry for kvm_cma_resv_ratio kernel param

[PATCH] Doc: admin-guide: Add entry for kvm_cma_resv_ratio kernel param

[sathnaga]

From: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>

Add document entry for kvm_cma_resv_ratio kernel param which
is used to alter the KVM contiguous memory allocation percentage
for hash pagetable allocation used by hash mode PowerPC KVM guests.

Cc: linux-kernel@vger.kernel.org
Cc: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Jonathan Corbet <corbet@lwn.net>  
Signed-off-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
---
 Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a1068742a6df..9cb126573c71 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -599,6 +599,15 @@
 			altogether. For more information, see
 			include/linux/dma-contiguous.h
 
+        kvm_cma_resv_ratio=n
+                        [PPC]
+                        Reserves given percentage from system memory area for
+                        contiguous memory allocation for KVM hash pagetable
+                        allocation.
+                        Bydefault it reserves 5% of total system memory.
+                        Format: <integer>
+                        Default: 5
+
 	cmo_free_hint=	[PPC] Format: { yes | no }
 			Specify whether pages are marked as being inactive
 			when they are freed.  This is used in CMO environments
-- 
2.26.2

Re: [PATCH] Doc: admin-guide: Add entry for kvm_cma_resv_ratio kernel param

[Randy Dunlap]

On 9/15/20 11:11 PM, sathnaga@linux.vnet.ibm.com wrote:
> From: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
> 
> Add document entry for kvm_cma_resv_ratio kernel param which
> is used to alter the KVM contiguous memory allocation percentage
> for hash pagetable allocation used by hash mode PowerPC KVM guests.
> 
> Cc: linux-kernel@vger.kernel.org
> Cc: kvm-ppc@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Jonathan Corbet <corbet@lwn.net>  
> Signed-off-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
> ---
>  Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index a1068742a6df..9cb126573c71 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -599,6 +599,15 @@
>  			altogether. For more information, see
>  			include/linux/dma-contiguous.h
>  
> +        kvm_cma_resv_ratio=n
> +                        [PPC]

You can put [PPC] on the line above.

> +                        Reserves given percentage from system memory area for
> +                        contiguous memory allocation for KVM hash pagetable
> +                        allocation.
> +                        Bydefault it reserves 5% of total system memory.

			   By default

> +                        Format: <integer>
> +                        Default: 5
> +

and please use tabs for indentation, not all spaces.

>  	cmo_free_hint=	[PPC] Format: { yes | no }
>  			Specify whether pages are marked as being inactive
>  			when they are freed.  This is used in CMO environments
> 

Entries in kernel-parameters.txt should be sorted into dictionary order,
so please put that with the other kvm parameters.

thanks.
-- 
~Randy

Re: [PATCH] Doc: admin-guide: Add entry for kvm_cma_resv_ratio kernel param

[Satheesh Rajendran]

Hi Randy,

Thanks for the comments, will send a V2 fixing them.

On Tue, Sep 15, 2020 at 11:18:52PM -0700, Randy Dunlap wrote:
> On 9/15/20 11:11 PM, sathnaga@linux.vnet.ibm.com wrote:
> > From: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
> > 
> > Add document entry for kvm_cma_resv_ratio kernel param which
> > is used to alter the KVM contiguous memory allocation percentage
> > for hash pagetable allocation used by hash mode PowerPC KVM guests.
> > 
> > Cc: linux-kernel@vger.kernel.org
> > Cc: kvm-ppc@vger.kernel.org
> > Cc: linuxppc-dev@lists.ozlabs.org
> > Cc: Paul Mackerras <paulus@samba.org>
> > Cc: Michael Ellerman <mpe@ellerman.id.au>
> > Cc: Jonathan Corbet <corbet@lwn.net>  
> > Signed-off-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
> > ---
> >  Documentation/admin-guide/kernel-parameters.txt | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> > 
> > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> > index a1068742a6df..9cb126573c71 100644
> > --- a/Documentation/admin-guide/kernel-parameters.txt
> > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > @@ -599,6 +599,15 @@
> >  			altogether. For more information, see
> >  			include/linux/dma-contiguous.h
> >  
> > +        kvm_cma_resv_ratio=n
> > +                        [PPC]
> 
> You can put [PPC] on the line above.
> 
sure
> > +                        Reserves given percentage from system memory area for
> > +                        contiguous memory allocation for KVM hash pagetable
> > +                        allocation.
> > +                        Bydefault it reserves 5% of total system memory.
> 
> 			   By default
> 
> > +                        Format: <integer>
> > +                        Default: 5
> > +
> 
> and please use tabs for indentation, not all spaces.
> 
sure
> >  	cmo_free_hint=	[PPC] Format: { yes | no }
> >  			Specify whether pages are marked as being inactive
> >  			when they are freed.  This is used in CMO environments
> > 
> 
> Entries in kernel-parameters.txt should be sorted into dictionary order,
> so please put that with the other kvm parameters.
> 
sure.
> thanks.
> -- 
> ~Randy
> 

Thanks!
-Satheesh.