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| author | Andrea Parri <parri.andrea@gmail.com> | 2023-03-23 02:37:51 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2023-03-24 10:24:48 -0700 |
| commit | cc4a29819b0df9f3a2e7e0d5dee0830a3072d5aa (patch) | |
| tree | d4bd54529a6b48d806c39cd1da0855ff16072daf /tools/memory-model | |
| parent | 05dc8470b3bfcad6b84bcf5953172ce26cfb2bd9 (diff) | |
| download | lwn-cc4a29819b0df9f3a2e7e0d5dee0830a3072d5aa.tar.gz lwn-cc4a29819b0df9f3a2e7e0d5dee0830a3072d5aa.zip | |
tools/memory-model: Remove out-of-date SRCU documentation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sections (among other things), making such documentation out-of-date.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out-of-date documentation.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.txt | 27 |
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. |