Re: [PATCH v2 02/17] dma-contiguous: simplify cma_early_percent_memory()

[Baoquan He]

On 08/02/20 at 07:35pm, Mike Rapoport wrote:
> From: Mike Rapoport 
> 
> The memory size calculation in cma_early_percent_memory() traverses
> memblock.memory rather than simply call memblock_phys_mem_size(). The
> comment in that function suggests that at some point there should have been
> call to memblock_analyze() before memblock_phys_mem_size() could be used.
> As of now, there is no memblock_analyze() at all and
> memblock_phys_mem_size() can be used as soon as cold-plug memory is
> registerd with memblock.
> 
> Replace loop over memblock.memory with a call to memblock_phys_mem_size().
> 
> Signed-off-by: Mike Rapoport 
> Reviewed-by: Christoph Hellwig 
> ---
>  kernel/dma/contiguous.c | 11 +--
>  1 file changed, 1 insertion(+), 10 deletions(-)
> 
> diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
> index 15bc5026c485..1992afd8ca7b 100644
> --- a/kernel/dma/contiguous.c
> +++ b/kernel/dma/contiguous.c
> @@ -73,16 +73,7 @@ early_param("cma", early_cma);
>  
>  static phys_addr_t __init __maybe_unused cma_early_percent_memory(void)
>  {
> - struct memblock_region *reg;
> - unsigned long total_pages = 0;
> -
> - /*
> -  * We cannot use memblock_phys_mem_size() here, because
> -  * memblock_analyze() has not been called yet.
> -  */
> - for_each_memblock(memory, reg)
> - total_pages += memblock_region_memory_end_pfn(reg) -
> -memblock_region_memory_base_pfn(reg);
> + unsigned long total_pages = PHYS_PFN(memblock_phys_mem_size());

Reviewed-by: Baoquan He 

>  
>   return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT;
>  }
> -- 
> 2.26.2
> 

[PATCH v2 02/17] dma-contiguous: simplify cma_early_percent_memory()

[Mike Rapoport]

From: Mike Rapoport 

The memory size calculation in cma_early_percent_memory() traverses
memblock.memory rather than simply call memblock_phys_mem_size(). The
comment in that function suggests that at some point there should have been
call to memblock_analyze() before memblock_phys_mem_size() could be used.
As of now, there is no memblock_analyze() at all and
memblock_phys_mem_size() can be used as soon as cold-plug memory is
registerd with memblock.

Replace loop over memblock.memory with a call to memblock_phys_mem_size().

Signed-off-by: Mike Rapoport 
Reviewed-by: Christoph Hellwig 
---
 kernel/dma/contiguous.c | 11 +--
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index 15bc5026c485..1992afd8ca7b 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -73,16 +73,7 @@ early_param("cma", early_cma);
 
 static phys_addr_t __init __maybe_unused cma_early_percent_memory(void)
 {
-   struct memblock_region *reg;
-   unsigned long total_pages = 0;
-
-   /*
-* We cannot use memblock_phys_mem_size() here, because
-* memblock_analyze() has not been called yet.
-*/
-   for_each_memblock(memory, reg)
-   total_pages += memblock_region_memory_end_pfn(reg) -
-  memblock_region_memory_base_pfn(reg);
+   unsigned long total_pages = PHYS_PFN(memblock_phys_mem_size());
 
return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT;
 }
-- 
2.26.2