lkml.org 
[lkml]   [2004]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Properly stop kernel threads on aic7xxx
    On Thu, Apr 01, 2004 at 05:04:03PM -0800, Andrew Morton wrote:
    > Andrea Arcangeli <andrea@suse.de> wrote:
    > >
    > > I'm also unsure why _all_ multipage allocations really need this
    > > compound thing setup and why can't the owner of the page take care of
    > > the refcounting itself by always using the head page. I may actually
    > > add a GFP bitflag asking for a multipage but w/o a compound setup. There
    > > are million ways to fix this, none of which is obvious.
    >
    > For direct-io into higher-order pages. When doing direct-io into a hugetlb
    > page we need to make sure that get_user_pages() pins the correct pageframe.

    we do the same in bigpages 2.4 just fine with a basic math on the page_t
    knowing it's 2M naturally aligned, very easy to find the head page on
    vmas with VM_HUGETLBFS.

    > Possibly we need to turn it on regardless of CONFIG_HUGETLBPAGE for people
    > who want to do direct-io or PEEKTEXT/POKETEXT into mmapped soundcard
    > buffers, for example. Perhaps there's a race which could permit direct-io
    > to write to a freed page via this route..
    >
    > Davem had some reason why he might want to turn on the compound logic
    > permanently - related to TCP access to/from higher-order pages, I think.

    currently it's turned on only with HUGTLBFS=y though.
    -
    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 14:02    [W:0.044 / U:122.380 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site