lkml.org 
[lkml]   [1998]   [Jul]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Kernel-bound applications?
    > Two things you might like to consider (they aren't necessarily
    > easy;-):
    >
    > - direct copying from writing process to reading process. This would
    > require you to read the page tables of the reading process so you can
    > copy_from_user() to the physical pages of the reading process. You'll
    > need to pin down the reading process pages

    I was thinking about this method. For blocking reads and writes, it seems
    like it would work great. But since X uses non-blocking i/o, I didn't
    really look into it. Anyone want to comment further on the feasibility?
    Perhaps a test in unix_stream_sendmsg and unix_stream_recvmsg that checks
    to see if it is a blocking socket and if true, does the direct copy.
    Reasonable???

    > - when user buffers are page aligned and at least one page in size, do
    > page flipping.

    I think I'll let someone else try this method :)

    > Both these techniques require page table accesses, which will have
    > some overhead. You might also need to consider cache issues.
    > Do it and benchmark it :-)

    I think I'll try the direct copy mechanism this weekend, along with some
    other ideas.

    --
    Kirk Petersen
    www.speakeasy.org/~kirk/

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.rutgers.edu
    Please read the FAQ at http://www.altern.org/andrebalsa/doc/lkml-faq.html

    \
     
     \ /
      Last update: 2005-03-22 13:43    [W:0.032 / U:89.996 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site