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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-09-29 12:34:40 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-12-04 12:26:51 -0800 |
| commit | 886ef5a18a4a771d5fdc0e23ae9373bb35d529e7 (patch) | |
| tree | cbecef5a7f6313614c0b8617411a764ab24c91ab /kernel/rcu/tree.c | |
| parent | 1de6e56ddc043437d335ee0455a1b34b73510c91 (diff) | |
| download | linux-0-day-886ef5a18a4a771d5fdc0e23ae9373bb35d529e7.tar.gz linux-0-day-886ef5a18a4a771d5fdc0e23ae9373bb35d529e7.tar.xz | |
rcu: Move smp_mb() from rcu_seq_snap() to rcu_exp_gp_seq_snap()
The memory barrier in rcu_seq_snap() is needed only for grace periods,
so this commit moves it to the grace-period-oriented wrapper
rcu_exp_gp_seq_snap().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree.c')
| -rw-r--r-- | kernel/rcu/tree.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index bd2605c144ccf..a4a0475aede9e 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3347,7 +3347,6 @@ static unsigned long rcu_seq_snap(unsigned long *sp) { unsigned long s; - smp_mb(); /* Caller's modifications seen first by other CPUs. */ s = (READ_ONCE(*sp) + 3) & ~0x1; smp_mb(); /* Above access must not bleed into critical section. */ return s; @@ -3374,6 +3373,7 @@ static void rcu_exp_gp_seq_end(struct rcu_state *rsp) } static unsigned long rcu_exp_gp_seq_snap(struct rcu_state *rsp) { + smp_mb(); /* Caller's modifications seen first by other CPUs. */ return rcu_seq_snap(&rsp->expedited_sequence); } static bool rcu_exp_gp_seq_done(struct rcu_state *rsp, unsigned long s) |