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path: root/fs/xfs/support/ktrace.c
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Diffstat (limited to 'fs/xfs/support/ktrace.c')
-rw-r--r--fs/xfs/support/ktrace.c21
1 files changed, 8 insertions, 13 deletions
diff --git a/fs/xfs/support/ktrace.c b/fs/xfs/support/ktrace.c
index 129067cfcb86..4e0444c0aca6 100644
--- a/fs/xfs/support/ktrace.c
+++ b/fs/xfs/support/ktrace.c
@@ -92,7 +92,7 @@ ktrace_alloc(int nentries, unsigned int __nocast sleep)
ktp->kt_entries = ktep;
ktp->kt_nentries = nentries;
- ktp->kt_index = 0;
+ atomic_set(&ktp->kt_index, 0);
ktp->kt_rollover = 0;
return ktp;
}
@@ -151,8 +151,6 @@ ktrace_enter(
void *val14,
void *val15)
{
- static DEFINE_SPINLOCK(wrap_lock);
- unsigned long flags;
int index;
ktrace_entry_t *ktep;
@@ -161,12 +159,8 @@ ktrace_enter(
/*
* Grab an entry by pushing the index up to the next one.
*/
- spin_lock_irqsave(&wrap_lock, flags);
- index = ktp->kt_index;
- if (++ktp->kt_index == ktp->kt_nentries)
- ktp->kt_index = 0;
- spin_unlock_irqrestore(&wrap_lock, flags);
-
+ index = atomic_add_return(1, &ktp->kt_index);
+ index = (index - 1) % ktp->kt_nentries;
if (!ktp->kt_rollover && index == ktp->kt_nentries - 1)
ktp->kt_rollover = 1;
@@ -199,11 +193,12 @@ int
ktrace_nentries(
ktrace_t *ktp)
{
- if (ktp == NULL) {
+ int index;
+ if (ktp == NULL)
return 0;
- }
- return (ktp->kt_rollover ? ktp->kt_nentries : ktp->kt_index);
+ index = atomic_read(&ktp->kt_index) % ktp->kt_nentries;
+ return (ktp->kt_rollover ? ktp->kt_nentries : index);
}
/*
@@ -228,7 +223,7 @@ ktrace_first(ktrace_t *ktp, ktrace_snap_t *ktsp)
int nentries;
if (ktp->kt_rollover)
- index = ktp->kt_index;
+ index = atomic_read(&ktp->kt_index) % ktp->kt_nentries;
else
index = 0;