diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-01-06 22:04:22 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-01-23 11:37:14 -0800 |
| commit | bb4e2c08bbfa8eb032db7814f6100086aac102d3 (patch) | |
| tree | 9f5f9cf8d14f4fb6e70dc72061d6c793032b3625 | |
| parent | d78973c32a210b0057b51880f7119bf2b61d5a65 (diff) | |
| download | linux-bb4e2c08bbfa8eb032db7814f6100086aac102d3.tar.bz2 | |
rcu: Eliminate unused expedited_normal counter
Expedited grace periods no longer fall back to normal grace periods
in response to lock contention, given that expedited grace periods
now use the rcu_node tree so as to avoid contention. This commit
therfore removes the expedited_normal counter.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| -rw-r--r-- | Documentation/RCU/trace.txt | 5 | ||||
| -rw-r--r-- | kernel/rcu/tree.h | 1 | ||||
| -rw-r--r-- | kernel/rcu/tree_trace.c | 3 |
3 files changed, 2 insertions, 7 deletions
diff --git a/Documentation/RCU/trace.txt b/Documentation/RCU/trace.txt index 00a3a38b375a..6549012033f9 100644 --- a/Documentation/RCU/trace.txt +++ b/Documentation/RCU/trace.txt @@ -237,7 +237,7 @@ o "ktl" is the low-order 16 bits (in hexadecimal) of the count of The output of "cat rcu/rcu_preempt/rcuexp" looks as follows: -s=21872 wd1=0 wd2=0 wd3=5 n=0 enq=0 sc=21872 +s=21872 wd1=0 wd2=0 wd3=5 enq=0 sc=21872 These fields are as follows: @@ -249,9 +249,6 @@ o "wd1", "wd2", and "wd3" are the number of times that an attempt completed an expedited grace period that satisfies the attempted request. "Our work is done." -o "n" is number of times that a concurrent CPU-hotplug operation - forced a fallback to a normal grace period. - o "enq" is the number of quiescent states still outstanding. o "sc" is the number of times that the attempt to start a diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index fe98dd24adf8..8f750dffb0dd 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -521,7 +521,6 @@ struct rcu_state { struct mutex exp_mutex; /* Serialize expedited GP. */ struct mutex exp_wake_mutex; /* Serialize wakeup. */ unsigned long expedited_sequence; /* Take a ticket. */ - atomic_long_t expedited_normal; /* # fallbacks to normal. */ atomic_t expedited_need_qs; /* # CPUs left to check in. */ struct swait_queue_head expedited_wq; /* Wait for check-ins. */ int ncpus_snap; /* # CPUs seen last time. */ diff --git a/kernel/rcu/tree_trace.c b/kernel/rcu/tree_trace.c index b1f28972872c..2e932cd1da31 100644 --- a/kernel/rcu/tree_trace.c +++ b/kernel/rcu/tree_trace.c @@ -194,9 +194,8 @@ static int show_rcuexp(struct seq_file *m, void *v) s2 += atomic_long_read(&rdp->exp_workdone2); s3 += atomic_long_read(&rdp->exp_workdone3); } - seq_printf(m, "s=%lu wd0=%lu wd1=%lu wd2=%lu wd3=%lu n=%lu enq=%d sc=%lu\n", + seq_printf(m, "s=%lu wd0=%lu wd1=%lu wd2=%lu wd3=%lu enq=%d sc=%lu\n", rsp->expedited_sequence, s0, s1, s2, s3, - atomic_long_read(&rsp->expedited_normal), atomic_read(&rsp->expedited_need_qs), rsp->expedited_sequence / 2); return 0; |