lkml.org 
[lkml]   [2007]   [Jul]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [patch 5/6] ps3: BD/DVD/CD-ROM Storage Driver
    From
    Date
    On Mon, 2007-07-16 at 14:16 +0200, Jens Axboe wrote:
    > On Mon, Jul 16 2007, Geert Uytterhoeven wrote:
    > > On Fri, 13 Jul 2007, Geert Uytterhoeven wrote:
    > > > Ah, that explains it. flush_dcache_page() is used in some drivers.
    > > > I'll update my patches. Thanks for the comments!
    > >
    > > Does this look OK?
    > > - Replaced KM_USER0 by KM_IRQ0 (all routines are either called from an
    > > interrupt handler, from .request_fn (ps3disk), or from .queuecommand
    > > (ps3rom))
    >
    > That looks good.
    >
    > > - Add a call to flush_kernel_dcache_page() in routines that write to buffers
    >
    > Hmm, I would have thought a flush_dcache_page() would be more
    > appropriate, the backing could be page cache pages.

    No ... that was the point of flush_kernel_dcache_page(). The page in
    question is page cache backed and contains user mappings. However, the
    block layer has already done a flush_dcache_page() in get_user_pages()
    and the user shouldn't be touching memory under I/O (unless they want
    self induced aliasing problems) so we're free to assume all the user
    cachelines are purged, hence all we have to do is flush the kernel alias
    to bring the page up to date and make the users see it correctly.

    James


    -
    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: 2007-07-16 15:49    [W:3.671 / U:0.164 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site