Mike Travis d0a9964e98 x86/platform/uv: Implement simple dump failover if kdump fails ... The ability to trigger a kdump using the system NMI command was added by commit 12ba6c990f ("x86/UV: Add kdump to UV NMI handler") Author: Mike Travis <travis@sgi.com> Date: Mon Sep 23 16:25:03 2013 -0500 This is useful because when kdump is working the information gathered is more informative than the original per CPU stack traces or "dump" option. However a number of things can go wrong with kdump and then the stack traces are more useful than nothing. The two most common reasons for kdump to not be available are: 1) if a problem occurs during boot before the kdump service is started, or 2) the kdump daemon failed to start. In either case the call to crash_kexec() returns unexpectedly. When this happens uv_nmi_kdump() also sets the uv_nmi_kexec_failed flag which causes the slave CPU's to also return to the NMI handler. Upon this unexpected return to the NMI handler, the NMI handler will revert to the "dump" action which uses show_regs() to obtain a process trace dump for all the CPU's. Other minor changes: The "dump" action now generates both the show_regs() stack trace and show instruction pointer information. Whereas the "ips" action only shows instruction pointers for non-idle CPU's. This is more like an abbreviated "ps" display. Change printk(KERN_DEFAULT...) --> pr_info() Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: George Beshers <gbeshers@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Hedi Berriche <hedi@sgi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russ Anderson <rja@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>		2015-09-14 15:31:30 +02:00
..
Makefile	x86/UV: Move NMI support	2013-09-24 09:02:02 +02:00
bios_uv.c	x86/efi: Delete most of the efi_call* macros	2014-04-17 13:26:30 +01:00
tlb_uv.c	x86: Fix up obsolete __cpu_set() function usage	2015-03-02 14:28:17 +01:00
uv_irq.c	x86/irq: Use accessor irq_data_get_node()	2015-07-13 21:22:46 +02:00
uv_nmi.c	x86/platform/uv: Implement simple dump failover if kdump fails	2015-09-14 15:31:30 +02:00
uv_sysfs.c	driver-core: remove sysdev.h usage.	2011-12-21 16:26:03 -08:00
uv_time.c	x86/uv/time: Migrate to new set-state interface	2015-07-30 21:25:38 +02:00