Eric Lee / smarc-fsl-linux-kernel

30 Oct, 2005

1 commit

  • 4c21e2f24   [PATCH] mm: split page table lock ... Browse Code »

    Christoph Lameter demonstrated very poor scalability on the SGI 512-way, with
    a many-threaded application which concurrently initializes different parts of
    a large anonymous area.

    This patch corrects that, by using a separate spinlock per page table page, to
    guard the page table entries in that page, instead of using the mm's single
    page_table_lock. (But even then, page_table_lock is still used to guard page
    table allocation, and anon_vma allocation.)

    In this implementation, the spinlock is tucked inside the struct page of the
    page table page: with a BUILD_BUG_ON in case it overflows - which it would in
    the case of 32-bit PA-RISC with spinlock debugging enabled.

    Splitting the lock is not quite for free: another cacheline access. Ideally,
    I suppose we would use split ptlock only for multi-threaded processes on
    multi-cpu machines; but deciding that dynamically would have its own costs.
    So for now enable it by config, at some number of cpus - since the Kconfig
    language doesn't support inequalities, let preprocessor compare that with
    NR_CPUS. But I don't think it's worth being user-configurable: for good
    testing of both split and unsplit configs, split now at 4 cpus, and perhaps
    change that to 8 later.

    There is a benefit even for singly threaded processes: kswapd can be attacking
    one part of the mm while another part is busy faulting.

    Signed-off-by: Hugh Dickins
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Hugh Dickins
     

09 Oct, 2005

1 commit

  • dd0fc66fb   [PATCH] gfp flags annotations - part 1 ... Browse Code »

    - added typedef unsigned int __nocast gfp_t;

    - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
    the same warnings as far as sparse is concerned, doesn't change
    generated code (from gcc point of view we replaced unsigned int with
    typedef) and documents what's going on far better.

    Signed-off-by: Al Viro
    Signed-off-by: Linus Torvalds

    Al Viro
     

26 Jun, 2005

1 commit

17 Apr, 2005

1 commit

  • 1da177e4c   Linux-2.6.12-rc2 ... Browse Code »

    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