lkml.org 
[lkml]   [2007]   [Jun]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] trim memory not covered by WB MTRRs
    Hi!

    > On some machines, buggy BIOSes don't properly setup WB MTRRs to
    > cover all available RAM, meaning the last few megs (or even gigs)
    > of memory will be marked uncached. Since Linux tends to allocate
    > from high memory addresses first, this causes the machine to be
    > unusably slow as soon as the kernel starts really using memory
    > (i.e. right around init time).

    > + if ((highest_addr >> PAGE_SHIFT) != end_pfn) {
    > + printk(KERN_WARNING "***************\n");
    > + printk(KERN_WARNING "**** WARNING: likely BIOS bug\n");
    > + printk(KERN_WARNING "**** MTRRs don't cover all of "
    > + "memory, trimmed %ld pages\n", end_pfn -
    > + (highest_addr >> PAGE_SHIFT));
    > + printk(KERN_WARNING "***************\n");
    > + end_pfn = highest_addr >> PAGE_SHIFT;

    Missing 4K of memory is not worth 4K of junk in syslog per boot. Can
    you drop the stars and stop shouting?

    Pavel
    --
    (english) http://www.livejournal.com/~pavelmachek
    (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
    -
    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: 2007-06-12 16:53    [W:0.019 / U:89.824 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site