lkml.org 
[lkml]   [1998]   [Jul]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] New phys_addr() syscall
    Alan Cox writes:
    > > People writing pure userspace network drivers may also find this handy
    > > if they want to DMA directly into userspace.
    >
    > It doesnt help. You have locking and copy/write issues to worry about for
    > the DMA case. This seems an extremely fringe and bizarre syscall to consider
    > for general use!

    What issues? If I pin down a set of pages, I can then get their
    physical address and tell the card to DMA its heart out. How exactly
    is this going to fail?

    I'm not claiming this syscall will be of general use: it is most
    certainly specialised. However I don't see any argument for
    restricting access.

    BTW: I wrote this primarily for my memory tester.

    Regards,

    Richard....

    -
    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:0.021 / U:30.148 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site