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| author |   Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-03-28 19:57:45 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-04-12 08:23:43 -0700 |
| commit | d3d3a3ccc4a8f1f254fb6788081f35bebe374174 (patch) | |
| tree | d5da6f64b71d990aeefae5649197db2eea8494c4 | |
| parent | doc: Update the comparisons rule in rcu_dereference.txt (diff) | |
| download | linux-dev-d3d3a3ccc4a8f1f254fb6788081f35bebe374174.tar.xz linux-dev-d3d3a3ccc4a8f1f254fb6788081f35bebe374174.zip | |
doc: Emphasize that "toy" RCU requires recursive rwlock
Reported-by: "yangzc@uit.com.cn" <yangzc@uit.com.cn>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| -rw-r--r-- | Documentation/RCU/whatisRCU.txt | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt index 6b0337008f9c..8c131a1c62ea 100644 --- a/Documentation/RCU/whatisRCU.txt +++ b/Documentation/RCU/whatisRCU.txt @@ -562,7 +562,9 @@ This section presents a "toy" RCU implementation that is based on familiar locking primitives. Its overhead makes it a non-starter for real-life use, as does its lack of scalability. It is also unsuitable for realtime use, since it allows scheduling latency to "bleed" from -one read-side critical section to another. +one read-side critical section to another. It also assumes recursive +reader-writer locks: If you try this with non-recursive locks, and +you allow nested rcu_read_lock() calls, you can deadlock. However, it is probably the easiest implementation to relate to, so is a good starting point. |