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    SubjectRe: RFC: remove __read_mostly
    Matt Mackall a écrit :
    > On Thu, Dec 13, 2007 at 11:20:44PM +0100, Adrian Bunk wrote:
    >
    >> I tried the following patch with a full x86 .config [1]:
    >>
    >> --- a/include/asm-x86/cache.h
    >> +++ b/include/asm-x86/cache.h
    >> -#define __read_mostly __attribute__((__section__(".data.read_mostly")))
    >> +/* #define __read_mostly __attribute__((__section__(".data.read_mostly"))) */
    >>
    >> The result [2,3] was:
    >>
    >> -rwxrwxr-x 1 bunk bunk 46607243 2007-12-13 19:50 vmlinux.old
    >> -rwxrwxr-x 1 bunk bunk 46598691 2007-12-13 21:55 vmlinux
    >>
    >> It's not a surprise that the kernel can become bigger when __read_mostly
    >> gets used, especially in cases where __read_mostly prevents gcc
    >> optimizations.
    >>
    >> My question is:
    >> Is there anywhere in the kernel a case where __read_mostly brings a
    >> measurable improvement or can it be removed?
    >>
    >
    > Yes, but perhaps we can put it under CONFIG_BASE_FULL?
    >
    >
    Yes, we probably can do something like that (in addition to !CONFIG_SMP)





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