lkml.org 
[lkml]   [2003]   [Apr]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: cow-ahead N pages for fault clustering
    >> > >> Ah, you probably don't want to do that ... it's very expensive.
    >> > >> Moreover, if you exec 2ns later, all the effort will be wasted ...
    >> > >> and it's very hard to deterministically predict whether you'll exec
    >> > >> or not (stupid UNIX semantics). Doing it lazily is probably best,
    >> > >> and as to "nodes would not have to reference the memory from
    >> > >> others" - you're still doing that, you're just batching it on the
    >> > >> front end.
    >> > >
    >> > > True... What about a vma-level COW-ahead just like we have a
    >> > > file-level read-ahead, then? I mean batching the COW at
    >> > > unCOW-because-of-write time.
    >> >
    >> > That'd be interesting ... and you can test that on a UP box, is not
    >> > just NUMA. Depends on the workload quite heavily, I suspect.
    >> >
    >> > > btw, COW-ahead sound really silly :)
    >> >
    >> > Yeah. So be sure to call it that if it works out ... we need more
    >> > things like that ;-) Moooooo.
    >>
    >> What about the attached one? I'm compiling it right now to test in UML :)
    >>
    >> [ snip fake-NUMA-on-SMP discussion ]
    >>
    >
    > OK, too quick for me... this next one applies, compiles and boots on
    > 2.5.66 + uml. Now I wonder how can I test if this is useful... ideas?

    Well, benchmark it ;-) My favourite trick is to just
    "/usr/bin/time make bzImage" on some fixed kernel version & config,
    but aim7 / aim9 is pretty easy to set up too, and might be interesting.

    M.

    -
    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: 2005-03-22 13:34    [W:0.046 / U:0.180 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site