[lkml]   [2002]   [Jan]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: Note describing poor dcache utilization under high memory pressure

    On Tue, 29 Jan 2002, Oliver Xymoron wrote:
    > I don't think read-only for the tables is sufficient if the pages
    > themselves are writable.

    At least on x86, the WRITE bit in the page directory entries will override
    any bits int he PTE. In other words, it doesn't make the page directory
    entries thmselves unwritable - it makes the final pages unwritable.

    Which are exactly the semantics we want.

    I have this strong feeling (but am lazy enough to not try to find the
    documentation) that on alpha the access bits in the upper page tables are
    just ignored (ie you have to actually turn off the present bit), which is
    a bit sad as it shouldn't matter from a PAL-code standpoint (just two more
    "and" instructions to and all the levels access bits together).


    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:15    [W:0.022 / U:7.124 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site