lkml.org 
[lkml]   [2007]   [Feb]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [patch 05/11] syslets: core code
    >  - it assumes we are going to make these complex state machines (which I 
    > don't believe for a second that a real program will do)

    They've not had the chance before and there are certain chains of them
    which make huge amounts of sense because you don't want to keep taking
    completion hits. Not so much looping ones but stuff like

    cork write sendfile uncork close

    are very natural sequences.

    There seem to be a lot of typical sequences it doesn't represent however
    (consider the trivial copy case where you use the result one syscall into
    the next)

    > - it assumes that we're going to make many async system calls that go
    > together (which breaks the whole notion of having different libraries
    > using this for their own internal reasons - they may not even *know*
    > about other libraries that _also_ do async IO for *their* reasons)

    They can each register their own async objects. They need to do this
    anyway so that the libraries can use asynchronous I/O and hide it from
    applications.

    > this "AIO atom" in the first place, WHICH WE KNOW IS INCORRECT, since
    > current users use "aio_read()" that simply doesn't have that and
    > doesn't build up any such data structures.

    Do current users do this because that is all they have, because it is
    hard, or because the current option is all that makes sense ?

    The ability to avoid asynchronous completion waits and
    complete/wake/despatch cycles is a good thing of itself. I don't know if
    it justifies the rest but it has potential for excellent performance.

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

    \
     
     \ /
      Last update: 2007-02-14 22:47    [W:2.480 / U:0.092 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site