| Message ID | 20220831181435.2695936-3-paulmck@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | SRCU polled grace-period updates for v6.1 | expand |
diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index 92c002d654828..a2af24f214676 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -240,10 +240,10 @@ EXPORT_SYMBOL_GPL(start_poll_synchronize_srcu); */ bool poll_state_synchronize_srcu(struct srcu_struct *ssp, unsigned long cookie) { - bool ret = USHORT_CMP_GE(READ_ONCE(ssp->srcu_idx), cookie); + unsigned short cur_s = READ_ONCE(ssp->srcu_idx); barrier(); - return ret; + return USHORT_CMP_GE(cur_s, cookie) || USHORT_CMP_LT(cur_s, cookie - 3); } EXPORT_SYMBOL_GPL(poll_state_synchronize_srcu);
This commit applies the more-precise grace-period-state check used by rcu_seq_done_exact() to poll_state_synchronize_srcu(). This is important because Tiny SRCU uses a 16-bit counter, which can wrap quite quickly. If counter wrap continues to be a problem, then expanding ->srcu_idx and ->srcu_idx_max to 32 bits might be warranted. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> --- kernel/rcu/srcutiny.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)