diff options
| author | Ingo Molnar <mingo@elte.hu> | 2009-03-05 21:48:31 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-05 21:48:50 +0100 |
| commit | a1413c89ae6a4b7a9a43f7768934a81ffb5c629a (patch) | |
| tree | 7e16be26407c5fd4dfbfeb98b11590809a963664 /include/linux/rcupreempt.h | |
| parent | f254f3909efaf59ca2d0f408de2d044dace60706 (diff) | |
| parent | dd4124a8a06bca89c077a16437edac010f0bb993 (diff) | |
| download | talos-obmc-linux-a1413c89ae6a4b7a9a43f7768934a81ffb5c629a.tar.gz talos-obmc-linux-a1413c89ae6a4b7a9a43f7768934a81ffb5c629a.zip | |
Merge branch 'x86/urgent' into x86/core
Conflicts:
arch/x86/include/asm/fixmap_64.h
Semantic merge:
arch/x86/include/asm/fixmap.h
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/rcupreempt.h')
| -rw-r--r-- | include/linux/rcupreempt.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/rcupreempt.h b/include/linux/rcupreempt.h index 3e05c09b54a2..74304b4538d8 100644 --- a/include/linux/rcupreempt.h +++ b/include/linux/rcupreempt.h @@ -142,4 +142,19 @@ static inline void rcu_exit_nohz(void) #define rcu_exit_nohz() do { } while (0) #endif /* CONFIG_NO_HZ */ +/* + * A context switch is a grace period for rcupreempt synchronize_rcu() + * only during early boot, before the scheduler has been initialized. + * So, how the heck do we get a context switch? Well, if the caller + * invokes synchronize_rcu(), they are willing to accept a context + * switch, so we simply pretend that one happened. + * + * After boot, there might be a blocked or preempted task in an RCU + * read-side critical section, so we cannot then take the fastpath. + */ +static inline int rcu_blocking_is_gp(void) +{ + return num_online_cpus() == 1 && !rcu_scheduler_active; +} + #endif /* __LINUX_RCUPREEMPT_H */ |
