evie/android_kernel_oneplus_msm8998
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rcu: Allow task-level idle entry/exit nesting

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The current task-level idle entry/exit code forces an entry/exit on
each call, regardless of the nesting level.  This commit therefore
properly accounts for nesting.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
This commit is contained in:
Paul E. McKenney 2013-10-04 18:48:55 -07:00
parent 96d3fd0d31
commit 3a5924052a
1 changed files with 8 additions and 6 deletions
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12
kernel/rcu/tree.c
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@ -418,11 +418,12 @@ static void rcu_eqs_enter(bool user)
rdtp = this_cpu_ptr(&rcu_dynticks); rdtp = this_cpu_ptr(&rcu_dynticks);
oldval = rdtp->dynticks_nesting; oldval = rdtp->dynticks_nesting;
WARN_ON_ONCE((oldval & DYNTICK_TASK_NEST_MASK) == 0); WARN_ON_ONCE((oldval & DYNTICK_TASK_NEST_MASK) == 0);
if ((oldval & DYNTICK_TASK_NEST_MASK) == DYNTICK_TASK_NEST_VALUE) if ((oldval & DYNTICK_TASK_NEST_MASK) == DYNTICK_TASK_NEST_VALUE) {
rdtp->dynticks_nesting = 0; rdtp->dynticks_nesting = 0;
else
rdtp->dynticks_nesting -= DYNTICK_TASK_NEST_VALUE;
rcu_eqs_enter_common(rdtp, oldval, user); rcu_eqs_enter_common(rdtp, oldval, user);
} else {
rdtp->dynticks_nesting -= DYNTICK_TASK_NEST_VALUE;
}
} }
/** /**
@ -540,12 +541,13 @@ static void rcu_eqs_exit(bool user)
rdtp = this_cpu_ptr(&rcu_dynticks); rdtp = this_cpu_ptr(&rcu_dynticks);
oldval = rdtp->dynticks_nesting; oldval = rdtp->dynticks_nesting;
WARN_ON_ONCE(oldval < 0); WARN_ON_ONCE(oldval < 0);
if (oldval & DYNTICK_TASK_NEST_MASK) if (oldval & DYNTICK_TASK_NEST_MASK) {
rdtp->dynticks_nesting += DYNTICK_TASK_NEST_VALUE; rdtp->dynticks_nesting += DYNTICK_TASK_NEST_VALUE;
else } else {
rdtp->dynticks_nesting = DYNTICK_TASK_EXIT_IDLE; rdtp->dynticks_nesting = DYNTICK_TASK_EXIT_IDLE;
rcu_eqs_exit_common(rdtp, oldval, user); rcu_eqs_exit_common(rdtp, oldval, user);
} }
}
/** /**
* rcu_idle_exit - inform RCU that current CPU is leaving idle * rcu_idle_exit - inform RCU that current CPU is leaving idle