[GIT PULL] x86/debug change for v4.4

From: Ingo Molnar
Date: Tue Nov 03 2015 - 06:05:24 EST


Linus,

Please pull the latest x86-debug-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-debug-for-linus

# HEAD: 0d44975d1e2791f6df2b84b182f49d815ba3c9e0 x86/kgdb: Replace bool_int_array[NR_CPUS] with bitmap

A single debugging related commit: compress the memory usage of a kgdb data
structure.

Thanks,

Ingo

------------------>
Denys Vlasenko (1):
x86/kgdb: Replace bool_int_array[NR_CPUS] with bitmap


arch/x86/kernel/kgdb.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index d6178d9791db..44256a62702b 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -511,26 +511,31 @@ single_step_cont(struct pt_regs *regs, struct die_args *args)
return NOTIFY_STOP;
}

-static int was_in_debug_nmi[NR_CPUS];
+static DECLARE_BITMAP(was_in_debug_nmi, NR_CPUS);

static int kgdb_nmi_handler(unsigned int cmd, struct pt_regs *regs)
{
+ int cpu;
+
switch (cmd) {
case NMI_LOCAL:
if (atomic_read(&kgdb_active) != -1) {
/* KGDB CPU roundup */
- kgdb_nmicallback(raw_smp_processor_id(), regs);
- was_in_debug_nmi[raw_smp_processor_id()] = 1;
+ cpu = raw_smp_processor_id();
+ kgdb_nmicallback(cpu, regs);
+ set_bit(cpu, was_in_debug_nmi);
touch_nmi_watchdog();
+
return NMI_HANDLED;
}
break;

case NMI_UNKNOWN:
- if (was_in_debug_nmi[raw_smp_processor_id()]) {
- was_in_debug_nmi[raw_smp_processor_id()] = 0;
+ cpu = raw_smp_processor_id();
+
+ if (__test_and_clear_bit(cpu, was_in_debug_nmi))
return NMI_HANDLED;
- }
+
break;
default:
/* do nothing */
--
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