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| author |   Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-01-30 17:23:19 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-03-31 13:34:07 -0700 |
| commit | e2fd9d35847d1936398d44c4df68dceb3d7f64e7 (patch) | |
| tree | 1893e200e6f5e87065b38fedfc9f74d19a4079b7 /kernel/rcu/tree_trace.c | |
| parent | rcu: Add expedited-grace-period event tracing (diff) | |
| download | linux-dev-e2fd9d35847d1936398d44c4df68dceb3d7f64e7.tar.xz linux-dev-e2fd9d35847d1936398d44c4df68dceb3d7f64e7.zip | |
rcu: Remove expedited GP funnel-lock bypass
Commit #cdacbe1f91264 ("rcu: Add fastpath bypassing funnel locking")
turns out to be a pessimization at high load because it forces a tree
full of tasks to wait for an expedited grace period that they probably
do not need. This commit therefore removes this optimization.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree_trace.c')
| -rw-r--r-- | kernel/rcu/tree_trace.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/kernel/rcu/tree_trace.c b/kernel/rcu/tree_trace.c index 1088e64f01ad..d149c412a4e5 100644 --- a/kernel/rcu/tree_trace.c +++ b/kernel/rcu/tree_trace.c @@ -185,17 +185,16 @@ static int show_rcuexp(struct seq_file *m, void *v) int cpu; struct rcu_state *rsp = (struct rcu_state *)m->private; struct rcu_data *rdp; - unsigned long s0 = 0, s1 = 0, s2 = 0, s3 = 0; + unsigned long s1 = 0, s2 = 0, s3 = 0; for_each_possible_cpu(cpu) { rdp = per_cpu_ptr(rsp->rda, cpu); - s0 += atomic_long_read(&rdp->expedited_workdone0); s1 += atomic_long_read(&rdp->expedited_workdone1); s2 += atomic_long_read(&rdp->expedited_workdone2); s3 += atomic_long_read(&rdp->expedited_workdone3); } - seq_printf(m, "s=%lu wd0=%lu wd1=%lu wd2=%lu wd3=%lu n=%lu enq=%d sc=%lu\n", - rsp->expedited_sequence, s0, s1, s2, s3, + seq_printf(m, "s=%lu wd1=%lu wd2=%lu wd3=%lu n=%lu enq=%d sc=%lu\n", + rsp->expedited_sequence, s1, s2, s3, atomic_long_read(&rsp->expedited_normal), atomic_read(&rsp->expedited_need_qs), rsp->expedited_sequence / 2); |