Commit 7bc069c6 authored by Jan Beulich's avatar Jan Beulich Committed by Ingo Molnar

x86: fix spin_is_contended()

The masked difference is what needs to be compared against 1, rather
than the difference of masked values (which can be negative).
Signed-off-by: default avatarJan Beulich <jbeulich@novell.com>
Acked-by: default avatarNick Piggin <npiggin@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 8bb85190
......@@ -65,7 +65,7 @@ static inline int __ticket_spin_is_contended(raw_spinlock_t *lock)
{
int tmp = ACCESS_ONCE(lock->slock);
return (((tmp >> 8) & 0xff) - (tmp & 0xff)) > 1;
return (((tmp >> 8) - tmp) & 0xff) > 1;
}
static __always_inline void __ticket_spin_lock(raw_spinlock_t *lock)
......@@ -127,7 +127,7 @@ static inline int __ticket_spin_is_contended(raw_spinlock_t *lock)
{
int tmp = ACCESS_ONCE(lock->slock);
return (((tmp >> 16) & 0xffff) - (tmp & 0xffff)) > 1;
return (((tmp >> 16) - tmp) & 0xffff) > 1;
}
static __always_inline void __ticket_spin_lock(raw_spinlock_t *lock)
......
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