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Diffstat (limited to 'Documentation/RCU/UP.txt')
| -rw-r--r-- | Documentation/RCU/UP.txt | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/Documentation/RCU/UP.txt b/Documentation/RCU/UP.txt index 90ec5341ee98..53bde717017b 100644 --- a/Documentation/RCU/UP.txt +++ b/Documentation/RCU/UP.txt @@ -86,10 +86,8 @@ even on a UP system. So do not do it! Even on a UP system, the RCU infrastructure -must- respect grace periods, and -must- invoke callbacks from a known environment in which no locks are held. -It -is- safe for synchronize_sched() and synchronize_rcu_bh() to return -immediately on an UP system. It is also safe for synchronize_rcu() -to return immediately on UP systems, except when running preemptable -RCU. +Note that it -is- safe for synchronize_rcu() to return immediately on +UP systems, including !PREEMPT SMP builds running on UP systems. Quick Quiz #3: Why can't synchronize_rcu() return immediately on UP systems running preemptable RCU? |