From 47cab6a722d44c71c4f8224017ef548522243cf4 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Aug 2009 09:31:54 +0200 Subject: debug lockups: Improve lockup detection, fix generic arch fallback As Andrew noted, my previous patch ("debug lockups: Improve lockup detection") broke/removed SysRq-L support from architecture that do not provide a __trigger_all_cpu_backtrace implementation. Restore a fallback path and clean up the SysRq-L machinery a bit: - Rename the arch method to arch_trigger_all_cpu_backtrace() - Simplify the define - Document the method a bit - in the hope of more architectures adding support for it. [ The patch touches Sparc code for the rename. ] Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Andrew Morton Cc: Linus Torvalds Cc: "David S. Miller" LKML-Reference: <20090802140809.7ec4bb6b.akpm@linux-foundation.org> Signed-off-by: Ingo Molnar --- include/linux/nmi.h | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 29af2d5df097..b752e807adde 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -28,8 +28,23 @@ static inline void acpi_nmi_disable(void) { } static inline void acpi_nmi_enable(void) { } #endif -#ifndef trigger_all_cpu_backtrace -#define trigger_all_cpu_backtrace() do { } while (0) +/* + * Create trigger_all_cpu_backtrace() out of the arch-provided + * base function. Return whether such support was available, + * to allow calling code to fall back to some other mechanism: + */ +#ifdef arch_trigger_all_cpu_backtrace +static inline bool trigger_all_cpu_backtrace(void) +{ + arch_trigger_all_cpu_backtrace(); + + return true; +} +#else +static inline bool trigger_all_cpu_backtrace(void) +{ + return false; +} #endif #endif -- cgit v1.2.3-59-g8ed1b