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authorAndrea Parri <parri.andrea@gmail.com>2023-03-23 02:37:51 +0100
committerPaul E. McKenney <paulmck@kernel.org>2023-03-24 10:24:48 -0700
commitcc4a29819b0df9f3a2e7e0d5dee0830a3072d5aa (patch)
treed4bd54529a6b48d806c39cd1da0855ff16072daf /tools/memory-model
parent05dc8470b3bfcad6b84bcf5953172ce26cfb2bd9 (diff)
tools/memory-model: Remove out-of-date SRCU documentation
Commit 6cd244c87428 ("tools/memory-model: Provide exact SRCU semantics") changed the semantics of partially overlapping SRCU read-side critical sections (among other things), making such documentation out-of-date. The new, semantic changes are discussed in explanation.txt. Remove the out-of-date documentation. Signed-off-by: Andrea Parri <parri.andrea@gmail.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'tools/memory-model')
-rw-r--r--tools/memory-model/Documentation/litmus-tests.txt27
1 files changed, 1 insertions, 26 deletions
diff --git a/tools/memory-model/Documentation/litmus-tests.txt b/tools/memory-model/Documentation/litmus-tests.txt
index 26554b1c5575..acac527328a1 100644
--- a/tools/memory-model/Documentation/litmus-tests.txt
+++ b/tools/memory-model/Documentation/litmus-tests.txt
@@ -1028,32 +1028,7 @@ Limitations of the Linux-kernel memory model (LKMM) include:
additional call_rcu() process to the site of the
emulated rcu-barrier().
- e. Although sleepable RCU (SRCU) is now modeled, there
- are some subtle differences between its semantics and
- those in the Linux kernel. For example, the kernel
- might interpret the following sequence as two partially
- overlapping SRCU read-side critical sections:
-
- 1 r1 = srcu_read_lock(&my_srcu);
- 2 do_something_1();
- 3 r2 = srcu_read_lock(&my_srcu);
- 4 do_something_2();
- 5 srcu_read_unlock(&my_srcu, r1);
- 6 do_something_3();
- 7 srcu_read_unlock(&my_srcu, r2);
-
- In contrast, LKMM will interpret this as a nested pair of
- SRCU read-side critical sections, with the outer critical
- section spanning lines 1-7 and the inner critical section
- spanning lines 3-5.
-
- This difference would be more of a concern had anyone
- identified a reasonable use case for partially overlapping
- SRCU read-side critical sections. For more information
- on the trickiness of such overlapping, please see:
- https://paulmck.livejournal.com/40593.html
-
- f. Reader-writer locking is not modeled. It can be
+ e. Reader-writer locking is not modeled. It can be
emulated in litmus tests using atomic read-modify-write
operations.