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| author | Ingo Molnar <mingo@elte.hu> | 2011-01-14 15:30:16 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-01-14 15:30:16 +0100 |
| commit | 1161ec944916069ceec21c487e30247d9ff22857 (patch) | |
| tree | 741385cbfde51286f502790cdfb77b1af2953944 /kernel | |
| parent | rtmutex: Fix comment about why new_owner can be NULL in wake_futex_pi() (diff) | |
| parent | rcu: avoid pointless blocked-task warnings (diff) | |
| download | linux-1161ec944916069ceec21c487e30247d9ff22857.tar.xz linux-1161ec944916069ceec21c487e30247d9ff22857.zip | |
Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu into core/urgent
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcutiny.c | 3 | ||||
| -rw-r--r-- | kernel/srcu.c | 15 |
2 files changed, 15 insertions, 3 deletions
diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c index 034493724749..0c343b9a46d5 100644 --- a/kernel/rcutiny.c +++ b/kernel/rcutiny.c @@ -189,7 +189,8 @@ static int rcu_kthread(void *arg) unsigned long flags; for (;;) { - wait_event(rcu_kthread_wq, have_rcu_kthread_work != 0); + wait_event_interruptible(rcu_kthread_wq, + have_rcu_kthread_work != 0); morework = rcu_boost(); local_irq_save(flags); work = have_rcu_kthread_work; diff --git a/kernel/srcu.c b/kernel/srcu.c index 98d8c1e80edb..73ce23feaea9 100644 --- a/kernel/srcu.c +++ b/kernel/srcu.c @@ -156,6 +156,16 @@ void __srcu_read_unlock(struct srcu_struct *sp, int idx) EXPORT_SYMBOL_GPL(__srcu_read_unlock); /* + * We use an adaptive strategy for synchronize_srcu() and especially for + * synchronize_srcu_expedited(). We spin for a fixed time period + * (defined below) to allow SRCU readers to exit their read-side critical + * sections. If there are still some readers after 10 microseconds, + * we repeatedly block for 1-millisecond time periods. This approach + * has done well in testing, so there is no need for a config parameter. + */ +#define SYNCHRONIZE_SRCU_READER_DELAY 10 + +/* * Helper function for synchronize_srcu() and synchronize_srcu_expedited(). */ static void __synchronize_srcu(struct srcu_struct *sp, void (*sync_func)(void)) @@ -207,11 +217,12 @@ static void __synchronize_srcu(struct srcu_struct *sp, void (*sync_func)(void)) * will have finished executing. We initially give readers * an arbitrarily chosen 10 microseconds to get out of their * SRCU read-side critical sections, then loop waiting 1/HZ - * seconds per iteration. + * seconds per iteration. The 10-microsecond value has done + * very well in testing. */ if (srcu_readers_active_idx(sp, idx)) - udelay(CONFIG_SRCU_SYNCHRONIZE_DELAY); + udelay(SYNCHRONIZE_SRCU_READER_DELAY); while (srcu_readers_active_idx(sp, idx)) schedule_timeout_interruptible(1); |