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authorAaron Tomlin <atomlin@redhat.com>2014-06-23 13:22:05 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-23 16:47:44 -0700
commitf3aca3d09525f87731ba6b892c9b010570bc54b4 (patch)
tree80c80be186f7bac74cb548444562ae6890938d83 /arch/sparc
parent88e15ce402c58f41037752da092683e90826742a (diff)
downloadlinux-f3aca3d09525f87731ba6b892c9b010570bc54b4.tar.bz2
nmi: provide the option to issue an NMI back trace to every cpu but current
Sometimes it is preferred not to use the trigger_all_cpu_backtrace() routine when one wants to avoid capturing a back trace for current. For instance if one was previously captured recently. This patch provides a new routine namely trigger_allbutself_cpu_backtrace() which offers the flexibility to issue an NMI to every cpu but current and capture a back trace accordingly. Patch x86 and sparc to support new routine. [dzickus@redhat.com: add stub in #else clause] [dzickus@redhat.com: don't print message in single processor case, wrap with get/put_cpu based on Oleg's suggestion] [sfr@canb.auug.org.au: undo C99ism] Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/sparc')
-rw-r--r--arch/sparc/include/asm/irq_64.h2
-rw-r--r--arch/sparc/kernel/process_64.c18
2 files changed, 13 insertions, 7 deletions
diff --git a/arch/sparc/include/asm/irq_64.h b/arch/sparc/include/asm/irq_64.h
index 375cffcf7dbd..91d219381306 100644
--- a/arch/sparc/include/asm/irq_64.h
+++ b/arch/sparc/include/asm/irq_64.h
@@ -89,7 +89,7 @@ static inline unsigned long get_softint(void)
return retval;
}
-void arch_trigger_all_cpu_backtrace(void);
+void arch_trigger_all_cpu_backtrace(bool);
#define arch_trigger_all_cpu_backtrace arch_trigger_all_cpu_backtrace
extern void *hardirq_stack[NR_CPUS];
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index b2988f25e230..027e09986194 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -239,7 +239,7 @@ static void __global_reg_poll(struct global_reg_snapshot *gp)
}
}
-void arch_trigger_all_cpu_backtrace(void)
+void arch_trigger_all_cpu_backtrace(bool include_self)
{
struct thread_info *tp = current_thread_info();
struct pt_regs *regs = get_irq_regs();
@@ -251,16 +251,22 @@ void arch_trigger_all_cpu_backtrace(void)
spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
- memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
-
this_cpu = raw_smp_processor_id();
- __global_reg_self(tp, regs, this_cpu);
+ memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
+
+ if (include_self)
+ __global_reg_self(tp, regs, this_cpu);
smp_fetch_global_regs();
for_each_online_cpu(cpu) {
- struct global_reg_snapshot *gp = &global_cpu_snapshot[cpu].reg;
+ struct global_reg_snapshot *gp;
+
+ if (!include_self && cpu == this_cpu)
+ continue;
+
+ gp = &global_cpu_snapshot[cpu].reg;
__global_reg_poll(gp);
@@ -292,7 +298,7 @@ void arch_trigger_all_cpu_backtrace(void)
static void sysrq_handle_globreg(int key)
{
- arch_trigger_all_cpu_backtrace();
+ arch_trigger_all_cpu_backtrace(true);
}
static struct sysrq_key_op sparc_globalreg_op = {