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| author |   Paul E. McKenney <paulmck@kernel.org> | 2022-07-28 12:00:50 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-08-31 04:58:14 -0700 |
| commit | ed336c6fe4c0110a56f6f237865ff9660de8c598 (patch) | |
| tree | 2575e764fb97798c5e74dfd4384929c840790657 | |
| parent | doc: Emphasize the need for explicit RCU read-side markers (diff) | |
| download | linux-dev-ed336c6fe4c0110a56f6f237865ff9660de8c598.tar.xz linux-dev-ed336c6fe4c0110a56f6f237865ff9660de8c598.zip | |
doc: Call out queue_rcu_work() for blocking RCU callbacks
The current checklist.rst file correctly notes that RCU callbacks execute
in BH context, and cannot block. This commit adds words advising people
needing callbacks to block to use workqueues, for example, by replacing
call_rcu() with queue_rcu_work().
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| -rw-r--r-- | Documentation/RCU/checklist.rst | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/RCU/checklist.rst b/Documentation/RCU/checklist.rst index 5eedef027d92..2db206fc3465 100644 --- a/Documentation/RCU/checklist.rst +++ b/Documentation/RCU/checklist.rst @@ -190,6 +190,9 @@ over a rather long period of time, but improvements are always welcome! 5. If call_rcu() or call_srcu() is used, the callback function will be called from softirq context. In particular, it cannot block. + If you need the callback to block, run that code in a workqueue + handler scheduled from the callback. The queue_rcu_work() + function does this for you in the case of call_rcu(). 6. Since synchronize_rcu() can block, it cannot be called from any sort of irq context. The same rule applies |