diff options
| author | Oleg Nesterov <oleg@tv-sign.ru> | 2006-10-04 02:17:17 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-04 07:55:31 -0700 |
| commit | 20e9751bd9dd6b832fd84ada27840360f7e877f1 (patch) | |
| tree | c598ff9cb9e540da7f8595f2c130f3674065e018 /include | |
| parent | 4b6c2cca6eef9cc4a15350bf1c61839e12e08b84 (diff) | |
[PATCH] rcu: simplify/improve batch tuning
Kill a hard-to-calculate 'rsinterval' boot parameter and per-cpu
rcu_data.last_rs_qlen. Instead, it adds adds a flag rcu_ctrlblk.signaled,
which records the fact that one of CPUs has sent a resched IPI since the
last rcu_start_batch().
Roughly speaking, we need two rcu_start_batch()s in order to move callbacks
from ->nxtlist to ->donelist. This means that when ->qlen exceeds qhimark
and continues to grow, we should send a resched IPI, and then do it again
after we gone through a quiescent state.
On the other hand, if it was already sent, we don't need to do it again
when another CPU detects overflow of the queue.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/rcupdate.h | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index b4ca73d6589..f6dd71bf8a4 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -66,6 +66,8 @@ struct rcu_ctrlblk { long completed; /* Number of the last completed batch */ int next_pending; /* Is the next batch already waiting? */ + int signaled; + spinlock_t lock ____cacheline_internodealigned_in_smp; cpumask_t cpumask; /* CPUs that need to switch in order */ /* for current batch to proceed. */ @@ -106,9 +108,6 @@ struct rcu_data { long blimit; /* Upper limit on a processed batch */ int cpu; struct rcu_head barrier; -#ifdef CONFIG_SMP - long last_rs_qlen; /* qlen during the last resched */ -#endif }; DECLARE_PER_CPU(struct rcu_data, rcu_data); |