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authorPetr Mladek <pmladek@suse.com>2023-06-16 17:06:15 +0200
committerAndrew Morton <akpm@linux-foundation.org>2023-06-19 16:25:29 -0700
commit0c68bda69665307bf835b0c433363e5073608c95 (patch)
tree024ddaf7ba97633be14ef3e743c03aa788206126 /arch/Kconfig
parent1356d0b966e7ed81832af35478b913495cf7792e (diff)
watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
arch_touch_nmi_watchdog() needs a different implementation for various hardlockup detector implementations. And it does nothing when any hardlockup detector is not built at all. arch_touch_nmi_watchdog() is declared via linux/nmi.h. And it must be defined as an empty function when there is no hardlockup detector. It is done directly in this header file for the perf and buddy detectors. And it is done in the included asm/linux.h for arch specific detectors. The reason probably is that the arch specific variants build the code using another conditions. For example, powerpc64/sparc64 builds the code when CONFIG_PPC_WATCHDOG is enabled. Another reason might be that these architectures define more functions in asm/nmi.h anyway. However the generic code actually knows when the function will be implemented. It happens when some full featured or the sparc64-specific hardlockup detector is built. In particular, CONFIG_HARDLOCKUP_DETECTOR can be enabled only when a generic or arch-specific full featured hardlockup detector is available. The only exception is sparc64 which can be built even when the global HARDLOCKUP_DETECTOR switch is disabled. The information about sparc64 is a bit complicated. The hardlockup detector is built there when CONFIG_HAVE_NMI_WATCHDOG is set and CONFIG_HAVE_HARDLOCKUP_DETECTOR_ARCH is not set. People might wonder whether this change really makes things easier. The motivation is: + The current logic in linux/nmi.h is far from obvious. For example, arch_touch_nmi_watchdog() is defined as {} when neither CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER nor CONFIG_HAVE_NMI_WATCHDOG is defined. + The change synchronizes the checks in lib/Kconfig.debug and in the generic code. + It is a step that will help cleaning HAVE_NMI_WATCHDOG related checks. The change should not change the existing behavior. Link: https://lkml.kernel.org/r/20230616150618.6073-4-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/Kconfig')
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