rcu: Make rcu_enter_nohz() pay attention to nesting

The old version of rcu_enter_nohz() forced RCU into nohz mode even if
the nesting count was non-zero.  This change causes rcu_enter_nohz()
to hold off for non-zero nesting counts.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney 2011-05-16 14:27:31 -07:00
parent b5904090c7
commit 4305ce7894

View File

@ -324,8 +324,8 @@ void rcu_enter_nohz(void)
smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
local_irq_save(flags);
rdtp = &__get_cpu_var(rcu_dynticks);
rdtp->dynticks++;
rdtp->dynticks_nesting--;
if (--rdtp->dynticks_nesting == 0)
rdtp->dynticks++;
WARN_ON_ONCE(rdtp->dynticks & 0x1);
local_irq_restore(flags);
}