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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-02-24 20:05:36 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-02-27 01:04:37 +0100 |
| commit | 5871968d531f39c23a8e6c69525bb705bca52e04 (patch) | |
| tree | 059ed811b5da15952bcb06844ecfcb437070be6b /kernel/rcu/tree.c | |
| parent | rcu: Fixes to NO_HZ_FULL sysidle accounting (diff) | |
| download | linux-5871968d531f39c23a8e6c69525bb705bca52e04.tar.xz linux-5871968d531f39c23a8e6c69525bb705bca52e04.zip | |
rcu: Tighten up affinity and check for sysidle
If the RCU grace-period kthread invoking rcu_sysidle_check_cpu()
happens to be running on the tick_do_timer_cpu initially,
then rcu_bind_gp_kthread() won't bind it. This kthread might
then migrate before invoking rcu_gp_fqs(), which will trigger the
WARN_ON_ONCE() in rcu_sysidle_check_cpu(). This commit therefore makes
rcu_bind_gp_kthread() do the binding even if the kthread is currently
on the same CPU. Because this incurs added overhead, this commit also
causes each RCU grace-period kthread to invoke rcu_bind_gp_kthread()
once at boot rather than at the beginning of each grace period.
And as long as rcu_bind_gp_kthread() is being modified, this commit
eliminates its #ifdef.
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 735bd7ee749a..a6972c20eaa5 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1707,7 +1707,6 @@ static int rcu_gp_init(struct rcu_state *rsp) struct rcu_node *rnp = rcu_get_root(rsp); ACCESS_ONCE(rsp->gp_activity) = jiffies; - rcu_bind_gp_kthread(); raw_spin_lock_irq(&rnp->lock); smp_mb__after_unlock_lock(); if (!ACCESS_ONCE(rsp->gp_flags)) { @@ -1895,6 +1894,7 @@ static int __noreturn rcu_gp_kthread(void *arg) struct rcu_state *rsp = arg; struct rcu_node *rnp = rcu_get_root(rsp); + rcu_bind_gp_kthread(); for (;;) { /* Handle grace-period start. */ |