234da7bcdc
In practice, it is harmless to voluntarily sleep in a rcu_read_lock() section if we are running under preempt rcu, but it is illegal if we build a kernel running non-preemptable rcu. Currently, might_sleep() doesn't notice sleepable operations under rcu_read_lock() sections if we are running under preemptable rcu because preempt_count() is left untouched after rcu_read_lock() in this case. But we want developers who test their changes under such config to notice the "sleeping while atomic" issues. So we add rcu_read_lock_nesting to prempt_count() in might_sleep() checks. [ v2: Handle rcu-tiny ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <1260991265-8451-1-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
109 lines
2.4 KiB
C
109 lines
2.4 KiB
C
/*
|
|
* Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*
|
|
* Copyright IBM Corporation, 2008
|
|
*
|
|
* Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
|
*
|
|
* For detailed explanation of Read-Copy Update mechanism see -
|
|
* Documentation/RCU
|
|
*/
|
|
#ifndef __LINUX_TINY_H
|
|
#define __LINUX_TINY_H
|
|
|
|
#include <linux/cache.h>
|
|
|
|
void rcu_sched_qs(int cpu);
|
|
void rcu_bh_qs(int cpu);
|
|
|
|
#define __rcu_read_lock() preempt_disable()
|
|
#define __rcu_read_unlock() preempt_enable()
|
|
#define __rcu_read_lock_bh() local_bh_disable()
|
|
#define __rcu_read_unlock_bh() local_bh_enable()
|
|
#define call_rcu_sched call_rcu
|
|
|
|
#define rcu_init_sched() do { } while (0)
|
|
extern void rcu_check_callbacks(int cpu, int user);
|
|
|
|
static inline int rcu_needs_cpu(int cpu)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Return the number of grace periods.
|
|
*/
|
|
static inline long rcu_batches_completed(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Return the number of bottom-half grace periods.
|
|
*/
|
|
static inline long rcu_batches_completed_bh(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
extern int rcu_expedited_torture_stats(char *page);
|
|
|
|
#define synchronize_rcu synchronize_sched
|
|
|
|
static inline void synchronize_rcu_expedited(void)
|
|
{
|
|
synchronize_sched();
|
|
}
|
|
|
|
static inline void synchronize_rcu_bh_expedited(void)
|
|
{
|
|
synchronize_sched();
|
|
}
|
|
|
|
struct notifier_block;
|
|
|
|
#ifdef CONFIG_NO_HZ
|
|
|
|
extern void rcu_enter_nohz(void);
|
|
extern void rcu_exit_nohz(void);
|
|
|
|
#else /* #ifdef CONFIG_NO_HZ */
|
|
|
|
static inline void rcu_enter_nohz(void)
|
|
{
|
|
}
|
|
|
|
static inline void rcu_exit_nohz(void)
|
|
{
|
|
}
|
|
|
|
#endif /* #else #ifdef CONFIG_NO_HZ */
|
|
|
|
static inline void rcu_scheduler_starting(void)
|
|
{
|
|
}
|
|
|
|
static inline void exit_rcu(void)
|
|
{
|
|
}
|
|
|
|
static inline int rcu_preempt_depth(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#endif /* __LINUX_RCUTINY_H */
|