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| author | Ingo Molnar <mingo@kernel.org> | 2020-07-31 00:15:53 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-07-31 00:15:53 +0200 |
| commit | c1cc4784ce6e8cceff1013709abd74bcbf7fbf24 (patch) | |
| tree | 5eaacf62240ec85a6ad9c7594e8ad8f7f783afc2 /Documentation/RCU/Design | |
| parent | 92ed301919932f777713b9172e525674157e983d (diff) | |
| parent | 13625c0a4074d3bab61b1dc70a828b574255f339 (diff) | |
| download | linux-c1cc4784ce6e8cceff1013709abd74bcbf7fbf24.tar.bz2 | |
Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull the v5.9 RCU bits from Paul E. McKenney:
- Documentation updates
- Miscellaneous fixes
- kfree_rcu updates
- RCU tasks updates
- Read-side scalability tests
- SRCU updates
- Torture-test updates
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'Documentation/RCU/Design')
| -rw-r--r-- | Documentation/RCU/Design/Requirements/Requirements.rst | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/Documentation/RCU/Design/Requirements/Requirements.rst b/Documentation/RCU/Design/Requirements/Requirements.rst index 75b8ca007a11..a69b5c43a10c 100644 --- a/Documentation/RCU/Design/Requirements/Requirements.rst +++ b/Documentation/RCU/Design/Requirements/Requirements.rst @@ -2583,7 +2583,12 @@ not work to have these markers in the trampoline itself, because there would need to be instructions following ``rcu_read_unlock()``. Although ``synchronize_rcu()`` would guarantee that execution reached the ``rcu_read_unlock()``, it would not be able to guarantee that execution -had completely left the trampoline. +had completely left the trampoline. Worse yet, in some situations +the trampoline's protection must extend a few instructions *prior* to +execution reaching the trampoline. For example, these few instructions +might calculate the address of the trampoline, so that entering the +trampoline would be pre-ordained a surprisingly long time before execution +actually reached the trampoline itself. The solution, in the form of `Tasks RCU <https://lwn.net/Articles/607117/>`__, is to have implicit read-side |