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Diffstat (limited to 'kernel/rcu/rcu.h')
| -rw-r--r-- | kernel/rcu/rcu.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index 4916077119f3..0adb55941aeb 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -120,6 +120,18 @@ static inline bool rcu_seq_done(unsigned long *sp, unsigned long s) } /* + * Given a snapshot from rcu_seq_snap(), determine whether or not a + * full update-side operation has occurred, but do not allow the + * (ULONG_MAX / 2) safety-factor/guard-band. + */ +static inline bool rcu_seq_done_exact(unsigned long *sp, unsigned long s) +{ + unsigned long cur_s = READ_ONCE(*sp); + + return ULONG_CMP_GE(cur_s, s) || ULONG_CMP_LT(cur_s, s - (2 * RCU_SEQ_STATE_MASK + 1)); +} + +/* * Has a grace period completed since the time the old gp_seq was collected? */ static inline bool rcu_seq_completed_gp(unsigned long old, unsigned long new) |