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authorIngo Molnar <mingo@kernel.org>2016-02-09 04:26:02 -0500
committerIngo Molnar <mingo@kernel.org>2016-02-09 04:26:02 -0500
commit2a96fd7417a0eb501edfde9713555bd7c2eda302 (patch)
treeef00ebfbde662b94a0423a8816a0bbab37440c1e /lib/dump_stack.c
parentca59809ff6d572ae58fc6bedf7500f5a60fdbd64 (diff)
parent388f7b1d6e8ca06762e2454d28d6c3c55ad0fe95 (diff)
Merge tag 'v4.5-rc3' into locking/core, to refresh the tree
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib/dump_stack.c')
-rw-r--r--lib/dump_stack.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/lib/dump_stack.c b/lib/dump_stack.c
index 6745c6230db3..c30d07e99dba 100644
--- a/lib/dump_stack.c
+++ b/lib/dump_stack.c
@@ -25,6 +25,7 @@ static atomic_t dump_lock = ATOMIC_INIT(-1);
25 25
26asmlinkage __visible void dump_stack(void) 26asmlinkage __visible void dump_stack(void)
27{ 27{
28 unsigned long flags;
28 int was_locked; 29 int was_locked;
29 int old; 30 int old;
30 int cpu; 31 int cpu;
@@ -33,9 +34,8 @@ asmlinkage __visible void dump_stack(void)
33 * Permit this cpu to perform nested stack dumps while serialising 34 * Permit this cpu to perform nested stack dumps while serialising
34 * against other CPUs 35 * against other CPUs
35 */ 36 */
36 preempt_disable();
37
38retry: 37retry:
38 local_irq_save(flags);
39 cpu = smp_processor_id(); 39 cpu = smp_processor_id();
40 old = atomic_cmpxchg(&dump_lock, -1, cpu); 40 old = atomic_cmpxchg(&dump_lock, -1, cpu);
41 if (old == -1) { 41 if (old == -1) {
@@ -43,6 +43,7 @@ retry:
43 } else if (old == cpu) { 43 } else if (old == cpu) {
44 was_locked = 1; 44 was_locked = 1;
45 } else { 45 } else {
46 local_irq_restore(flags);
46 cpu_relax(); 47 cpu_relax();
47 goto retry; 48 goto retry;
48 } 49 }
@@ -52,7 +53,7 @@ retry:
52 if (!was_locked) 53 if (!was_locked)
53 atomic_set(&dump_lock, -1); 54 atomic_set(&dump_lock, -1);
54 55
55 preempt_enable(); 56 local_irq_restore(flags);
56} 57}
57#else 58#else
58asmlinkage __visible void dump_stack(void) 59asmlinkage __visible void dump_stack(void)