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  • Ingo Molnar's avatar
    [PATCH] smp_processor_id() cleanup · 39c715b7
    Ingo Molnar authored
    This patch implements a number of smp_processor_id() cleanup ideas that
    Arjan van de Ven and I came up with.
    The previous __smp_processor_id/_smp_processor_id/smp_processor_id API
    spaghetti was hard to follow both on the implementational and on the
    usage side.
    Some of the complexity arose from picking wrong names, some of the
    complexity comes from the fact that not all architectures defined
    In the new code, there are two externally visible symbols:
     - smp_processor_id(): debug variant.
     - raw_smp_processor_id(): nondebug variant. Replaces all existing
       uses of _smp_processor_id() and __smp_processor_id(). Defined
       by every SMP architecture in include/asm-*/smp.h.
    There is one new internal symbol, dependent on DEBUG_PREEMPT:
     - debug_smp_processor_id(): internal debug variant, mapped to
    Also, i moved debug_smp_processor_id() from lib/kernel_lock.c into a new
    lib/smp_processor_id.c file.  All related comments got updated and/or
    I have build/boot tested the following 8 .config combinations on x86:
    I have also build/boot tested x64 on UP/PREEMPT/DEBUG_PREEMPT.  (Other
    architectures are untested, but should work just fine.)
    Signed-off-by: default avatarIngo Molnar <>
    Signed-off-by: default avatarArjan van de Ven <>
    Signed-off-by: default avatarAndrew Morton <>
    Signed-off-by: default avatarLinus Torvalds <>