lkml.org 
[lkml]   [2021]   [Jun]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v2 5/9] mm: remove CONFIG_DISCONTIGMEM
    Date
    From: Mike Rapoport <rppt@linux.ibm.com>

    There are no architectures that support DISCONTIGMEM left.

    Remove the configuration option and the dead code it was guarding in the
    generic memory management code.

    Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
    ---
    include/asm-generic/memory_model.h | 37 ++++--------------------------
    include/linux/mmzone.h | 8 ++++---
    mm/Kconfig | 25 +++-----------------
    mm/page_alloc.c | 13 -----------
    4 files changed, 12 insertions(+), 71 deletions(-)

    diff --git a/include/asm-generic/memory_model.h b/include/asm-generic/memory_model.h
    index 7637fb46ba4f..a2c8ed60233a 100644
    --- a/include/asm-generic/memory_model.h
    +++ b/include/asm-generic/memory_model.h
    @@ -6,47 +6,18 @@

    #ifndef __ASSEMBLY__

    +/*
    + * supports 3 memory models.
    + */
    #if defined(CONFIG_FLATMEM)

    #ifndef ARCH_PFN_OFFSET
    #define ARCH_PFN_OFFSET (0UL)
    #endif

    -#elif defined(CONFIG_DISCONTIGMEM)
    -
    -#ifndef arch_pfn_to_nid
    -#define arch_pfn_to_nid(pfn) pfn_to_nid(pfn)
    -#endif
    -
    -#ifndef arch_local_page_offset
    -#define arch_local_page_offset(pfn, nid) \
    - ((pfn) - NODE_DATA(nid)->node_start_pfn)
    -#endif
    -
    -#endif /* CONFIG_DISCONTIGMEM */
    -
    -/*
    - * supports 3 memory models.
    - */
    -#if defined(CONFIG_FLATMEM)
    -
    #define __pfn_to_page(pfn) (mem_map + ((pfn) - ARCH_PFN_OFFSET))
    #define __page_to_pfn(page) ((unsigned long)((page) - mem_map) + \
    ARCH_PFN_OFFSET)
    -#elif defined(CONFIG_DISCONTIGMEM)
    -
    -#define __pfn_to_page(pfn) \
    -({ unsigned long __pfn = (pfn); \
    - unsigned long __nid = arch_pfn_to_nid(__pfn); \
    - NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
    -})
    -
    -#define __page_to_pfn(pg) \
    -({ const struct page *__pg = (pg); \
    - struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg)); \
    - (unsigned long)(__pg - __pgdat->node_mem_map) + \
    - __pgdat->node_start_pfn; \
    -})

    #elif defined(CONFIG_SPARSEMEM_VMEMMAP)

    @@ -70,7 +41,7 @@
    struct mem_section *__sec = __pfn_to_section(__pfn); \
    __section_mem_map_addr(__sec) + __pfn; \
    })
    -#endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
    +#endif /* CONFIG_FLATMEM/SPARSEMEM */

    /*
    * Convert a physical address to a Page Frame Number and back
    diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
    index 0d53eba1c383..700032e99419 100644
    --- a/include/linux/mmzone.h
    +++ b/include/linux/mmzone.h
    @@ -738,10 +738,12 @@ struct zonelist {
    struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
    };

    -#ifndef CONFIG_DISCONTIGMEM
    -/* The array of struct pages - for discontigmem use pgdat->lmem_map */
    +/*
    + * The array of struct pages for flatmem.
    + * It must be declared for SPARSEMEM as well because there are configurations
    + * that rely on that.
    + */
    extern struct page *mem_map;
    -#endif

    #ifdef CONFIG_TRANSPARENT_HUGEPAGE
    struct deferred_split {
    diff --git a/mm/Kconfig b/mm/Kconfig
    index 02d44e3420f5..218b96ccc84a 100644
    --- a/mm/Kconfig
    +++ b/mm/Kconfig
    @@ -19,7 +19,7 @@ choice

    config FLATMEM_MANUAL
    bool "Flat Memory"
    - depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) || ARCH_FLATMEM_ENABLE
    + depends on !ARCH_SPARSEMEM_ENABLE || ARCH_FLATMEM_ENABLE
    help
    This option is best suited for non-NUMA systems with
    flat address space. The FLATMEM is the most efficient
    @@ -32,21 +32,6 @@ config FLATMEM_MANUAL

    If unsure, choose this option (Flat Memory) over any other.

    -config DISCONTIGMEM_MANUAL
    - bool "Discontiguous Memory"
    - depends on ARCH_DISCONTIGMEM_ENABLE
    - help
    - This option provides enhanced support for discontiguous
    - memory systems, over FLATMEM. These systems have holes
    - in their physical address spaces, and this option provides
    - more efficient handling of these holes.
    -
    - Although "Discontiguous Memory" is still used by several
    - architectures, it is considered deprecated in favor of
    - "Sparse Memory".
    -
    - If unsure, choose "Sparse Memory" over this option.
    -
    config SPARSEMEM_MANUAL
    bool "Sparse Memory"
    depends on ARCH_SPARSEMEM_ENABLE
    @@ -62,17 +47,13 @@ config SPARSEMEM_MANUAL

    endchoice

    -config DISCONTIGMEM
    - def_bool y
    - depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL
    -
    config SPARSEMEM
    def_bool y
    depends on (!SELECT_MEMORY_MODEL && ARCH_SPARSEMEM_ENABLE) || SPARSEMEM_MANUAL

    config FLATMEM
    def_bool y
    - depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL
    + depends on !SPARSEMEM || FLATMEM_MANUAL

    config FLAT_NODE_MEM_MAP
    def_bool y
    @@ -85,7 +66,7 @@ config FLAT_NODE_MEM_MAP
    #
    config NEED_MULTIPLE_NODES
    def_bool y
    - depends on DISCONTIGMEM || NUMA
    + depends on NUMA

    #
    # SPARSEMEM_EXTREME (which is the default) does some bootmem
    diff --git a/mm/page_alloc.c b/mm/page_alloc.c
    index aaa1655cf682..6fc22482eaa8 100644
    --- a/mm/page_alloc.c
    +++ b/mm/page_alloc.c
    @@ -331,20 +331,7 @@ compound_page_dtor * const compound_page_dtors[NR_COMPOUND_DTORS] = {

    int min_free_kbytes = 1024;
    int user_min_free_kbytes = -1;
    -#ifdef CONFIG_DISCONTIGMEM
    -/*
    - * DiscontigMem defines memory ranges as separate pg_data_t even if the ranges
    - * are not on separate NUMA nodes. Functionally this works but with
    - * watermark_boost_factor, it can reclaim prematurely as the ranges can be
    - * quite small. By default, do not boost watermarks on discontigmem as in
    - * many cases very high-order allocations like THP are likely to be
    - * unsupported and the premature reclaim offsets the advantage of long-term
    - * fragmentation avoidance.
    - */
    -int watermark_boost_factor __read_mostly;
    -#else
    int watermark_boost_factor __read_mostly = 15000;
    -#endif
    int watermark_scale_factor = 10;

    static unsigned long nr_kernel_pages __initdata;
    --
    2.28.0
    \
     
     \ /
      Last update: 2021-06-04 08:51    [W:3.009 / U:0.164 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site