lkml.org 
[lkml]   [2006]   [Nov]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] i386-pda UP optimization
    Arjan van de Ven wrote:
    > segment register accesses really are not cheap.
    > Also really it'll be better to use the register userspace is not using,
    > but we had that discussion before; could you remind me why you picked
    > %gs in the first place?
    >

    To leave open the possibility of using the compiler's TLS support in the
    kernel for percpu. I also measured the cost of reloading %gs vs %fs,
    and found no difference between reloading a null selector vs a non-null
    selector.

    J

    -
    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: 2006-11-15 19:27    [W:0.022 / U:32.672 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site