lkml.org 
[lkml]   [1999]   [Nov]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: PATCH 2.3.26: kmalloc GFP_ZEROt
    On Wed, 10 Nov 1999, Gerard Roudier wrote:

    >zeroed with the cache invalidating or snooping the accesses. May-be having
    >some pool of zeroed memory or zeroing some memory is useful for security
    >issue, but speaking of pooled or cached objects, we probably want to most

    Yes, the _only_ point of the clear_page in the page fault path is
    security.

    >only zero parts that need to be so. The bzero-mania does not look fine
    >programming to me.

    Agreed. OTOH using a different chip for the bzero may really improve
    performances and scale better.

    The bzero-mania with a minimal slowdown under heavy load still doesn't
    convince me instead...

    >PS: If we want to be able to write zero-filled blocks to a disk without
    >bzero overhead, for example, we can reserve a small amount of physical
    >pages filled with zeros at startup.

    Currently there's at least one page reserved that must stay zeroed all the
    time. It's the ZERO_PAGE(). mapping /dev/null always fallback on the
    ZERO_PAGE. you can read it as many times and whenever you want.

    Andrea


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

    \
     
     \ /
      Last update: 2005-03-22 13:54    [W:6.464 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site