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authorDavid S. Miller <davem@davemloft.net>2008-05-19 23:46:00 -0700
committerDavid S. Miller <davem@davemloft.net>2008-05-20 00:33:45 -0700
commit93dae5b70e7c1c8e927d22e1c20a941ca376906a (patch)
treef255087706b9d176455b17e4384f4632f59f4cde /arch/sparc64/kernel/smp.c
parent88278ca27a43ae503572b52ea2c171fbf45db5a2 (diff)
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sparc64: Add global register dumping facility.
When a cpu really is stuck in the kernel, it can be often impossible to figure out which cpu is stuck where. The worst case is when the stuck cpu has interrupts disabled. Therefore, implement a global cpu state capture that uses SMP message interrupts which are not disabled by the normal IRQ enable/disable APIs of the kernel. As long as we can get a sysrq 'y' to the kernel, we can get a dump. Even if the console interrupt cpu is wedged, we can trigger it from userspace using /proc/sysrq-trigger The output is made compact so that this facility is more useful on high cpu count systems, which is where this facility will likely find itself the most useful :) Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc64/kernel/smp.c')
-rw-r--r--arch/sparc64/kernel/smp.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c
index 0d6403a630ac..fa63c68a1819 100644
--- a/arch/sparc64/kernel/smp.c
+++ b/arch/sparc64/kernel/smp.c
@@ -900,6 +900,9 @@ extern unsigned long xcall_flush_tlb_mm;
extern unsigned long xcall_flush_tlb_pending;
extern unsigned long xcall_flush_tlb_kernel_range;
extern unsigned long xcall_report_regs;
+#ifdef CONFIG_MAGIC_SYSRQ
+extern unsigned long xcall_fetch_glob_regs;
+#endif
extern unsigned long xcall_receive_signal;
extern unsigned long xcall_new_mmu_context_version;
#ifdef CONFIG_KGDB
@@ -1080,6 +1083,13 @@ void smp_report_regs(void)
smp_cross_call(&xcall_report_regs, 0, 0, 0);
}
+#ifdef CONFIG_MAGIC_SYSRQ
+void smp_fetch_global_regs(void)
+{
+ smp_cross_call(&xcall_fetch_glob_regs, 0, 0, 0);
+}
+#endif
+
/* We know that the window frames of the user have been flushed
* to the stack before we get here because all callers of us
* are flush_tlb_*() routines, and these run after flush_cache_*()
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