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Diffstat (limited to 'Documentation/RCU/whatisRCU.txt')
| -rw-r--r-- | Documentation/RCU/whatisRCU.txt | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt index 07cb93b82ba..4f41a60e511 100644 --- a/Documentation/RCU/whatisRCU.txt +++ b/Documentation/RCU/whatisRCU.txt @@ -184,7 +184,17 @@ synchronize_rcu() blocking, it registers a function and argument which are invoked after all ongoing RCU read-side critical sections have completed. This callback variant is particularly useful in situations where - it is illegal to block. + it is illegal to block or where update-side performance is + critically important. + + However, the call_rcu() API should not be used lightly, as use + of the synchronize_rcu() API generally results in simpler code. + In addition, the synchronize_rcu() API has the nice property + of automatically limiting update rate should grace periods + be delayed. This property results in system resilience in face + of denial-of-service attacks. Code using call_rcu() should limit + update rate in order to gain this same sort of resilience. See + checklist.txt for some approaches to limiting the update rate. rcu_assign_pointer() @@ -790,7 +800,6 @@ RCU pointer update: RCU grace period: - synchronize_kernel (deprecated) synchronize_net synchronize_sched synchronize_rcu |