diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-03-28 22:57:45 -0400 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-04-12 11:23:43 -0400 |
| commit | d3d3a3ccc4a8f1f254fb6788081f35bebe374174 (patch) | |
| tree | d5da6f64b71d990aeefae5649197db2eea8494c4 /Documentation/RCU | |
| parent | 93728af0a1f63e13d6f7f56a434965b05b8b2abd (diff) | |
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>
Diffstat (limited to 'Documentation/RCU')
| -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 | |||
| 562 | familiar locking primitives. Its overhead makes it a non-starter for | 562 | familiar locking primitives. Its overhead makes it a non-starter for |
| 563 | real-life use, as does its lack of scalability. It is also unsuitable | 563 | real-life use, as does its lack of scalability. It is also unsuitable |
| 564 | for realtime use, since it allows scheduling latency to "bleed" from | 564 | for realtime use, since it allows scheduling latency to "bleed" from |
| 565 | one read-side critical section to another. | 565 | one read-side critical section to another. It also assumes recursive |
| 566 | reader-writer locks: If you try this with non-recursive locks, and | ||
| 567 | you allow nested rcu_read_lock() calls, you can deadlock. | ||
| 566 | 568 | ||
| 567 | However, it is probably the easiest implementation to relate to, so is | 569 | However, it is probably the easiest implementation to relate to, so is |
| 568 | a good starting point. | 570 | a good starting point. |