• Don Zickus's avatar
    x86, nmi_watchdog: Remove ARCH_HAS_NMI_WATCHDOG and rely on CONFIG_HARDLOCKUP_DETECTOR · 4a7863cc
    Don Zickus authored
    The x86 arch has shifted its use of the nmi_watchdog from a
    local implementation to the global one provide by
    kernel/watchdog.c.  This shift has caused a whole bunch of
    compile problems under different config options.  I attempt to
    simplify things with the patch below.
    
    In order to simplify things, I had to come to terms with the
    meaning of two terms ARCH_HAS_NMI_WATCHDOG and
    CONFIG_HARDLOCKUP_DETECTOR.  Basically they mean the same thing,
    the former on a local level and the latter on a global level.
    
    With the old x86 nmi watchdog gone, there is no need to rely on
    defining the ARCH_HAS_NMI_WATCHDOG variable because it doesn't
    make sense any more.  x86 will now use the global
    implementation.
    
    The changes below do a few things.  First it changes the few
    places that relied on ARCH_HAS_NMI_WATCHDOG to use
    CONFIG_X86_LOCAL_APIC (the former was an alias for the latter
    anyway, so nothing unusual here).  Those pieces of code were
    relying more on local apic functionality the nmi watchdog
    functionality, so the change should make sense.
    
    Second, I removed the x86 implementation of
    touch_nmi_watchdog().  It isn't need now, instead x86 will rely
    on kernel/watchdog.c's implementation.
    
    Third, I removed the #define ARCH_HAS_NMI_WATCHDOG itself from
    x86.  And tweaked the include/linux/nmi.h file to tell users to
    look for an externally defined touch_nmi_watchdog in the case of
    ARCH_HAS_NMI_WATCHDOG _or_ CONFIG_HARDLOCKUP_DETECTOR. This
    changes removes some of the ugliness in that file.
    
    Finally, I added a Kconfig dependency for
    CONFIG_HARDLOCKUP_DETECTOR that said you can't have
    ARCH_HAS_NMI_WATCHDOG _and_ CONFIG_HARDLOCKUP_DETECTOR.  You can
    only have one nmi_watchdog.
    
    Tested with
    ARCH=i386: allnoconfig, defconfig, allyesconfig, (various broken
    configs) ARCH=x86_64: allnoconfig, defconfig, allyesconfig,
    (various broken configs)
    
    Hopefully, after this patch I won't get any more compile broken
    emails. :-)
    
    v3:
      changed a couple of 'linux/nmi.h' -> 'asm/nmi.h' to pick-up correct function
      prototypes when CONFIG_HARDLOCKUP_DETECTOR is not set.
    Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: fweisbec@gmail.com
    LKML-Reference: <1293044403-14117-1-git-send-email-dzickus@redhat.com>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    4a7863cc
nmi.h 790 Bytes