lkml.org 
[lkml]   [2000]   [Aug]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] Re: Move of input drivers, some word needed from you
    Hi,

    > Now, currently, most of the recieve handling is postponed to the
    > bottom half. I question the usefulness of this optimization. It
    > certainly adds latency. What is it that needs to be done on reception
    > of a few chars? Copy the data to userspace, and hit the waitq of the
    > process that's waiting for data. If you want to prevent the races, use
    > a kernel-space circular buffer, and do the processing (copy to
    > userspace) in the context of the wokenup process.

    The input line handling in n_tty.c should IMO not be done on interrupt
    level. AFAIK it's the only reason put_char can't sleep and you can get the
    input line handling with a simple (but admittingly not very realistic)
    example to overflow, because it has to echo chars back and at some point
    it simply has to drop characters.

    bye, Roman

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

    \
     
     \ /
      Last update: 2005-03-22 12:37    [W:0.029 / U:0.268 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site