Re: [RFC PATCH 27/29] mm: remove nobootmem

Michal Hocko
2018-09-06T09:08:17Z

On Wed 05-09-18 18:59:42, Mike Rapoport wrote:
> Move a few remaining functions from nobootmem.c to memblock.c and remove
> nobootmem
>
> Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
> mm/Makefile | 1 -
> mm/memblock.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++
> mm/nobootmem.c | 128 ---------------------------------------------------------
> 3 files changed, 104 insertions(+), 129 deletions(-)
> delete mode 100644 mm/nobootmem.c
>
> diff --git a/mm/Makefile b/mm/Makefile
> index 0a3e72e..fb96c45 100644
> --- a/mm/Makefile
> +++ b/mm/Makefile
> @@ -42,7 +42,6 @@ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \
> debug.o $(mmu-y)
>
> obj-y += init-mm.o
> -obj-y += nobootmem.o
> obj-y += memblock.o
>
> ifdef CONFIG_MMU
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 55d7d50..3f76d40 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -82,6 +82,16 @@
> * initialization compltes.
> */
>
> +#ifndef CONFIG_NEED_MULTIPLE_NODES
> +struct pglist_data __refdata contig_page_data;
> +EXPORT_SYMBOL(contig_page_data);
> +#endif
> +
> +unsigned long max_low_pfn;
> +unsigned long min_low_pfn;
> +unsigned long max_pfn;
> +unsigned long long max_possible_pfn;
> +
> static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
> static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
> #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
> @@ -1959,6 +1969,100 @@ static int __init early_memblock(char *p)
> }
> early_param("memblock", early_memblock);
>
> +static void __init __free_pages_memory(unsigned long start, unsigned long end)
> +{
> + int order;
> +
> + while (start < end) {
> + order = min(MAX_ORDER - 1UL, __ffs(start));
> +
> + while (start + (1UL << order) > end)
> + order--;
> +
> + memblock_free_pages(pfn_to_page(start), start, order);
> +
> + start += (1UL << order);
> + }
> +}
> +
> +static unsigned long __init __free_memory_core(phys_addr_t start,
> + phys_addr_t end)
> +{
> + unsigned long start_pfn = PFN_UP(start);
> + unsigned long end_pfn = min_t(unsigned long,
> + PFN_DOWN(end), max_low_pfn);
> +
> + if (start_pfn >= end_pfn)
> + return 0;
> +
> + __free_pages_memory(start_pfn, end_pfn);
> +
> + return end_pfn - start_pfn;
> +}
> +
> +static unsigned long __init free_low_memory_core_early(void)
> +{
> + unsigned long count = 0;
> + phys_addr_t start, end;
> + u64 i;
> +
> + memblock_clear_hotplug(0, -1);
> +
> + for_each_reserved_mem_region(i, &start, &end)
> + reserve_bootmem_region(start, end);
> +
> + /*
> + * We need to use NUMA_NO_NODE instead of NODE_DATA(0)->node_id
> + * because in some case like Node0 doesn't have RAM installed
> + * low ram will be on Node1
> + */
> + for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end,
> + NULL)
> + count += __free_memory_core(start, end);
> +
> + return count;
> +}
> +
> +static int reset_managed_pages_done __initdata;
> +
> +void reset_node_managed_pages(pg_data_t *pgdat)
> +{
> + struct zone *z;
> +
> + for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
> + z->managed_pages = 0;
> +}
> +
> +void __init reset_all_zones_managed_pages(void)
> +{
> + struct pglist_data *pgdat;
> +
> + if (reset_managed_pages_done)
> + return;
> +
> + for_each_online_pgdat(pgdat)
> + reset_node_managed_pages(pgdat);
> +
> + reset_managed_pages_done = 1;
> +}
> +
> +/**
> + * memblock_free_all - release free pages to the buddy allocator
> + *
> + * Return: the number of pages actually released.
> + */
> +unsigned long __init memblock_free_all(void)
> +{
> + unsigned long pages;
> +
> + reset_all_zones_managed_pages();
> +
> + pages = free_low_memory_core_early();
> + totalram_pages += pages;
> +
> + return pages;
> +}
> +
> #if defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK)
>
> static int memblock_debug_show(struct seq_file *m, void *private)
> diff --git a/mm/nobootmem.c b/mm/nobootmem.c
> deleted file mode 100644
> index 9608bc5..0000000
> --- a/mm/nobootmem.c
> +++ /dev/null
> @@ -1,128 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -/*
> - * bootmem - A boot-time physical memory allocator and configurator
> - *
> - * Copyright (C) 1999 Ingo Molnar
> - * 1999 Kanoj Sarcar, SGI
> - * 2008 Johannes Weiner
> - *
> - * Access to this subsystem has to be serialized externally (which is true
> - * for the boot process anyway).
> - */
> -#include <linux/init.h>
> -#include <linux/pfn.h>
> -#include <linux/slab.h>
> -#include <linux/export.h>
> -#include <linux/kmemleak.h>
> -#include <linux/range.h>
> -#include <linux/memblock.h>
> -#include <linux/bootmem.h>
> -
> -#include <asm/bug.h>
> -#include <asm/io.h>
> -
> -#include "internal.h"
> -
> -#ifndef CONFIG_NEED_MULTIPLE_NODES
> -struct pglist_data __refdata contig_page_data;
> -EXPORT_SYMBOL(contig_page_data);
> -#endif
> -
> -unsigned long max_low_pfn;
> -unsigned long min_low_pfn;
> -unsigned long max_pfn;
> -unsigned long long max_possible_pfn;
> -
> -static void __init __free_pages_memory(unsigned long start, unsigned long end)
> -{
> - int order;
> -
> - while (start < end) {
> - order = min(MAX_ORDER - 1UL, __ffs(start));
> -
> - while (start + (1UL << order) > end)
> - order--;
> -
> - memblock_free_pages(pfn_to_page(start), start, order);
> -
> - start += (1UL << order);
> - }
> -}
> -
> -static unsigned long __init __free_memory_core(phys_addr_t start,
> - phys_addr_t end)
> -{
> - unsigned long start_pfn = PFN_UP(start);
> - unsigned long end_pfn = min_t(unsigned long,
> - PFN_DOWN(end), max_low_pfn);
> -
> - if (start_pfn >= end_pfn)
> - return 0;
> -
> - __free_pages_memory(start_pfn, end_pfn);
> -
> - return end_pfn - start_pfn;
> -}
> -
> -static unsigned long __init free_low_memory_core_early(void)
> -{
> - unsigned long count = 0;
> - phys_addr_t start, end;
> - u64 i;
> -
> - memblock_clear_hotplug(0, -1);
> -
> - for_each_reserved_mem_region(i, &start, &end)
> - reserve_bootmem_region(start, end);
> -
> - /*
> - * We need to use NUMA_NO_NODE instead of NODE_DATA(0)->node_id
> - * because in some case like Node0 doesn't have RAM installed
> - * low ram will be on Node1
> - */
> - for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end,
> - NULL)
> - count += __free_memory_core(start, end);
> -
> - return count;
> -}
> -
> -static int reset_managed_pages_done __initdata;
> -
> -void reset_node_managed_pages(pg_data_t *pgdat)
> -{
> - struct zone *z;
> -
> - for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
> - z->managed_pages = 0;
> -}
> -
> -void __init reset_all_zones_managed_pages(void)
> -{
> - struct pglist_data *pgdat;
> -
> - if (reset_managed_pages_done)
> - return;
> -
> - for_each_online_pgdat(pgdat)
> - reset_node_managed_pages(pgdat);
> -
> - reset_managed_pages_done = 1;
> -}
> -
> -/**
> - * memblock_free_all - release free pages to the buddy allocator
> - *
> - * Return: the number of pages actually released.
> - */
> -unsigned long __init memblock_free_all(void)
> -{
> - unsigned long pages;
> -
> - reset_all_zones_managed_pages();
> -
> - pages = free_low_memory_core_early();
> - totalram_pages += pages;
> -
> - return pages;
> -}
> --
> 2.7.4
>

--
Michal Hocko
SUSE Labs