22 Mar, 2006

1 commit

  • Centralize the page migration functions in anticipation of additional
    tinkering. Creates a new file mm/migrate.c

    1. Extract buffer_migrate_page() from fs/buffer.c

    2. Extract central migration code from vmscan.c

    3. Extract some components from mempolicy.c

    4. Export pageout() and remove_from_swap() from vmscan.c

    5. Make it possible to configure NUMA systems without page migration
    and non-NUMA systems with page migration.

    I had to so some #ifdeffing in mempolicy.c that may need a cleanup.

    Signed-off-by: Christoph Lameter
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Christoph Lameter
     

09 Jan, 2006

2 commits

  • configurable replacement for slab allocator

    This adds a CONFIG_SLAB option under CONFIG_EMBEDDED. When CONFIG_SLAB is
    disabled, the kernel falls back to using the 'SLOB' allocator.

    SLOB is a traditional K&R/UNIX allocator with a SLAB emulation layer,
    similar to the original Linux kmalloc allocator that SLAB replaced. It's
    signicantly smaller code and is more memory efficient. But like all
    similar allocators, it scales poorly and suffers from fragmentation more
    than SLAB, so it's only appropriate for small systems.

    It's been tested extensively in the Linux-tiny tree. I've also
    stress-tested it with make -j 8 compiles on a 3G SMP+PREEMPT box (not
    recommended).

    Here's a comparison for otherwise identical builds, showing SLOB saving
    nearly half a megabyte of RAM:

    $ size vmlinux*
    text data bss dec hex filename
    3336372 529360 190812 4056544 3de5e0 vmlinux-slab
    3323208 527948 190684 4041840 3dac70 vmlinux-slob

    $ size mm/{slab,slob}.o
    text data bss dec hex filename
    13221 752 48 14021 36c5 mm/slab.o
    1896 52 8 1956 7a4 mm/slob.o

    /proc/meminfo:
    SLAB SLOB delta
    MemTotal: 27964 kB 27980 kB +16 kB
    MemFree: 24596 kB 25092 kB +496 kB
    Buffers: 36 kB 36 kB 0 kB
    Cached: 1188 kB 1188 kB 0 kB
    SwapCached: 0 kB 0 kB 0 kB
    Active: 608 kB 600 kB -8 kB
    Inactive: 808 kB 812 kB +4 kB
    HighTotal: 0 kB 0 kB 0 kB
    HighFree: 0 kB 0 kB 0 kB
    LowTotal: 27964 kB 27980 kB +16 kB
    LowFree: 24596 kB 25092 kB +496 kB
    SwapTotal: 0 kB 0 kB 0 kB
    SwapFree: 0 kB 0 kB 0 kB
    Dirty: 4 kB 12 kB +8 kB
    Writeback: 0 kB 0 kB 0 kB
    Mapped: 560 kB 556 kB -4 kB
    Slab: 1756 kB 0 kB -1756 kB
    CommitLimit: 13980 kB 13988 kB +8 kB
    Committed_AS: 4208 kB 4208 kB 0 kB
    PageTables: 28 kB 28 kB 0 kB
    VmallocTotal: 1007312 kB 1007312 kB 0 kB
    VmallocUsed: 48 kB 48 kB 0 kB
    VmallocChunk: 1007264 kB 1007264 kB 0 kB

    (this work has been sponsored in part by CELF)

    From: Ingo Molnar

    Fix 32-bitness bugs in mm/slob.c.

    Signed-off-by: Matt Mackall
    Signed-off-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Matt Mackall
     
  • Add mm/util.c for functions common between SLAB and SLOB.

    Signed-off-by: Matt Mackall
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Matt Mackall
     

30 Oct, 2005

1 commit

  • This adds generic memory add/remove and supporting functions for memory
    hotplug into a new file as well as a memory hotplug kernel config option.

    Individual architecture patches will follow.

    For now, disable memory hotplug when swsusp is enabled. There's a lot of
    churn there right now. We'll fix it up properly once it calms down.

    Signed-off-by: Matt Tolentino
    Signed-off-by: Dave Hansen
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Dave Hansen
     

24 Jun, 2005

2 commits

  • - generic_file* file operations do no longer have a xip/non-xip split
    - filemap_xip.c implements a new set of fops that require get_xip_page
    aop to work proper. all new fops are exported GPL-only (don't like to
    see whatever code use those except GPL modules)
    - __xip_unmap now uses page_check_address, which is no longer static
    in rmap.c, and defined in linux/rmap.h
    - mm/filemap.h is now much more clean, plainly having just Linus'
    inline funcs moved here from filemap.c
    - fix includes in filemap_xip to make it build cleanly on i386

    Signed-off-by: Carsten Otte
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Carsten Otte
     
  • Sparsemem abstracts the use of discontiguous mem_maps[]. This kind of
    mem_map[] is needed by discontiguous memory machines (like in the old
    CONFIG_DISCONTIGMEM case) as well as memory hotplug systems. Sparsemem
    replaces DISCONTIGMEM when enabled, and it is hoped that it can eventually
    become a complete replacement.

    A significant advantage over DISCONTIGMEM is that it's completely separated
    from CONFIG_NUMA. When producing this patch, it became apparent in that NUMA
    and DISCONTIG are often confused.

    Another advantage is that sparse doesn't require each NUMA node's ranges to be
    contiguous. It can handle overlapping ranges between nodes with no problems,
    where DISCONTIGMEM currently throws away that memory.

    Sparsemem uses an array to provide different pfn_to_page() translations for
    each SECTION_SIZE area of physical memory. This is what allows the mem_map[]
    to be chopped up.

    In order to do quick pfn_to_page() operations, the section number of the page
    is encoded in page->flags. Part of the sparsemem infrastructure enables
    sharing of these bits more dynamically (at compile-time) between the
    page_zone() and sparsemem operations. However, on 32-bit architectures, the
    number of bits is quite limited, and may require growing the size of the
    page->flags type in certain conditions. Several things might force this to
    occur: a decrease in the SECTION_SIZE (if you want to hotplug smaller areas of
    memory), an increase in the physical address space, or an increase in the
    number of used page->flags.

    One thing to note is that, once sparsemem is present, the NUMA node
    information no longer needs to be stored in the page->flags. It might provide
    speed increases on certain platforms and will be stored there if there is
    room. But, if out of room, an alternate (theoretically slower) mechanism is
    used.

    This patch introduces CONFIG_FLATMEM. It is used in almost all cases where
    there used to be an #ifndef DISCONTIG, because SPARSEMEM and DISCONTIGMEM
    often have to compile out the same areas of code.

    Signed-off-by: Andy Whitcroft
    Signed-off-by: Dave Hansen
    Signed-off-by: Martin Bligh
    Signed-off-by: Adrian Bunk
    Signed-off-by: Yasunori Goto
    Signed-off-by: Bob Picco
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andy Whitcroft
     

17 Apr, 2005

1 commit

  • Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds