lkml.org 
[lkml]   [2014]   [Feb]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: [RFC] de-asmify the x86-64 system call slowpath
    From
    On Thu, Feb 6, 2014 at 2:24 PM, Kirill A. Shutemov <kirill@shutemov.name> wrote:
    >
    > If we want to reduce number of page fault with less overhead we probably
    > should concentrate on minor page fault -- populate pte around fault
    > address which already in page cache. It should cover scripting use-case
    > pretty well.

    That's what my patch largely does. Except I screwed up and didn't use
    FAULT_FLAG_ALLOW_RETRY in fault_around().

    Anyway, my patch kind of works, but I'm starting to hate it. I think I
    want to try to extend the "->fault()" interface to allow
    filemap_fault() to just fill in multiple pages.

    We alread have that "vmf->page" thing, we could make it a small array
    easily. That would allow proper gang lookup, and much more efficient
    "fill in multiple entries in one go" in mm/memory.c.

    > Heh! `man 3 mmap' actually suggests MAP_POPULATE | MAP_NONBLOCK.
    > What's the story beyond MAP_NONBLOCK?

    It does nothing, afaik.

    Linus


    \
     
     \ /
      Last update: 2014-02-07 02:41    [W:3.402 / U:0.344 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site