[PATCH] powerpc: increase MIN RMA size for CAS negotiation

[PATCH] powerpc: increase MIN RMA size for CAS negotiation

[Avnish Chouhan]

Change RMA size from 512 MB to 768 MB which will result 
in more RMA at boot time for PowerPC. When PowerPC LPAR use/uses vTPM,
Secure Boot or FADump, the 512 MB RMA memory is not sufficient for 
booting. With this 512 MB RMA, GRUB2 run out of memory and unable to 
load the necessary. Sometimes even usage of CDROM which requires more
memory for installation along with the options mentioned above troubles
the boot memory and result in boot failures. Increasing the RMA size 
will resolves multiple out of memory issues observed in PowerPC. 


Signed-off-by: Avnish Chouhan <avnish@linux.ibm.com>
---
 arch/powerpc/kernel/prom_init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index fbb68fc28ed3..c42fd5a826c0 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -1061,7 +1061,7 @@ static const struct ibm_arch_vec ibm_architecture_vec_template __initconst = {
 		.virt_base = cpu_to_be32(0xffffffff),
 		.virt_size = cpu_to_be32(0xffffffff),
 		.load_base = cpu_to_be32(0xffffffff),
-		.min_rma = cpu_to_be32(512),		/* 512MB min RMA */
+		.min_rma = cpu_to_be32(768),		/* 768MB min RMA */
 		.min_load = cpu_to_be32(0xffffffff),	/* full client load */
 		.min_rma_percent = 0,	/* min RMA percentage of total RAM */
 		.max_pft_size = 48,	/* max log_2(hash table size) */
-- 
2.43.5

Re: [PATCH] powerpc: increase MIN RMA size for CAS negotiation

[Madhavan Srinivasan]

On 12/5/24 3:40 PM, Avnish Chouhan wrote:
> Change RMA size from 512 MB to 768 MB which will result 
> in more RMA at boot time for PowerPC. When PowerPC LPAR use/uses vTPM,
> Secure Boot or FADump, the 512 MB RMA memory is not sufficient for 
> booting. With this 512 MB RMA, GRUB2 run out of memory and unable to 
> load the necessary. Sometimes even usage of CDROM which requires more
> memory for installation along with the options mentioned above troubles
> the boot memory and result in boot failures. Increasing the RMA size 
> will resolves multiple out of memory issues observed in PowerPC. 

Can you add more on the failure details here list a stack trace or dump,
also is there a selftest to verify the fix in qemu or lpar?

> 
> 
> Signed-off-by: Avnish Chouhan <avnish@linux.ibm.com>
> ---
>  arch/powerpc/kernel/prom_init.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
> index fbb68fc28ed3..c42fd5a826c0 100644
> --- a/arch/powerpc/kernel/prom_init.c
> +++ b/arch/powerpc/kernel/prom_init.c
> @@ -1061,7 +1061,7 @@ static const struct ibm_arch_vec ibm_architecture_vec_template __initconst = {
>  		.virt_base = cpu_to_be32(0xffffffff),
>  		.virt_size = cpu_to_be32(0xffffffff),
>  		.load_base = cpu_to_be32(0xffffffff),
> -		.min_rma = cpu_to_be32(512),		/* 512MB min RMA */
> +		.min_rma = cpu_to_be32(768),		/* 768MB min RMA */
>  		.min_load = cpu_to_be32(0xffffffff),	/* full client load */
>  		.min_rma_percent = 0,	/* min RMA percentage of total RAM */
>  		.max_pft_size = 48,	/* max log_2(hash table size) */