Re: [PATCH] sparc64: simplify reduce_memory() function
From: Mike Rapoport
Date: Sun Feb 17 2019 - 03:28:30 EST
Any comments on this?
On Tue, Feb 12, 2019 at 11:32:36AM +0200, Mike Rapoport wrote:
> The reduce_memory() function clampls the available memory to a limit
> defined by the "mem=" command line parameter. It takes into account the
> amount of already reserved memory and excludes it from the limit
> calculations.
>
> Rather than traverse memblocks and remove them by hand, use
> memblock_reserved_size() to account the reserved memory and
> memblock_enforce_memory_limit() to clamp the available memory.
>
> Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> ---
> arch/sparc/mm/init_64.c | 42 ++----------------------------------------
> 1 file changed, 2 insertions(+), 40 deletions(-)
>
> diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
> index b4221d3..478b818 100644
> --- a/arch/sparc/mm/init_64.c
> +++ b/arch/sparc/mm/init_64.c
> @@ -2261,19 +2261,6 @@ static unsigned long last_valid_pfn;
> static void sun4u_pgprot_init(void);
> static void sun4v_pgprot_init(void);
>
> -static phys_addr_t __init available_memory(void)
> -{
> - phys_addr_t available = 0ULL;
> - phys_addr_t pa_start, pa_end;
> - u64 i;
> -
> - for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &pa_start,
> - &pa_end, NULL)
> - available = available + (pa_end - pa_start);
> -
> - return available;
> -}
> -
> #define _PAGE_CACHE_4U (_PAGE_CP_4U | _PAGE_CV_4U)
> #define _PAGE_CACHE_4V (_PAGE_CP_4V | _PAGE_CV_4V)
> #define __DIRTY_BITS_4U (_PAGE_MODIFIED_4U | _PAGE_WRITE_4U | _PAGE_W_4U)
> @@ -2287,33 +2274,8 @@ static phys_addr_t __init available_memory(void)
> */
> static void __init reduce_memory(phys_addr_t limit_ram)
> {
> - phys_addr_t avail_ram = available_memory();
> - phys_addr_t pa_start, pa_end;
> - u64 i;
> -
> - if (limit_ram >= avail_ram)
> - return;
> -
> - for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &pa_start,
> - &pa_end, NULL) {
> - phys_addr_t region_size = pa_end - pa_start;
> - phys_addr_t clip_start = pa_start;
> -
> - avail_ram = avail_ram - region_size;
> - /* Are we consuming too much? */
> - if (avail_ram < limit_ram) {
> - phys_addr_t give_back = limit_ram - avail_ram;
> -
> - region_size = region_size - give_back;
> - clip_start = clip_start + give_back;
> - }
> -
> - memblock_remove(clip_start, region_size);
> -
> - if (avail_ram <= limit_ram)
> - break;
> - i = 0UL;
> - }
> + limit_ram += memblock_reserved_size();
> + memblock_enforce_memory_limit(limit_ram);
> }
>
> void __init paging_init(void)
> --
> 2.7.4
>
--
Sincerely yours,
Mike.