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| author | Paul E. McKenney | 2024-02-01 10:51:28 -0800 |
|---|---|---|
| committer | Paul E. McKenney | 2024-05-06 14:28:35 -0700 |
| commit | d2c470c491719130e9af2e80c1bd7223ac61ee93 (patch) | |
| tree | c17cd9b7ea9fe7f7e192ffce7e6c89e8a62633fa /Documentation | |
| parent | 39cd87c4eb2b893354f3b850f916353f2658ae6f (diff) | |
Documentation/litmus-tests: Add locking tests to README
This commit documents the litmus tests in the "locking" directory.
[ paulmck: Apply formatting feedback from Andrea Parri. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jade Alglave <j.alglave@ucl.ac.uk>
Cc: Luc Maranget <luc.maranget@inria.fr>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Akira Yokosawa <akiyks@gmail.com>
Cc: Daniel Lustig <dlustig@nvidia.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: <linux-arch@vger.kernel.org>
Cc: <linux-doc@vger.kernel.org>
Acked-by: Andrea Parri <parri.andrea@gmail.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/litmus-tests/README | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/Documentation/litmus-tests/README b/Documentation/litmus-tests/README index 658d37860d39..26ca56df0212 100644 --- a/Documentation/litmus-tests/README +++ b/Documentation/litmus-tests/README @@ -22,6 +22,35 @@ Atomic-RMW-ops-are-atomic-WRT-atomic_set.litmus NOTE: Require herd7 7.56 or later which supports "(void)expr". +locking (/locking directory) +---------------------------- + +DCL-broken.litmus + Demonstrates that double-checked locking needs more than just + the obvious lock acquisitions and releases. + +DCL-fixed.litmus + Demonstrates corrected double-checked locking that uses + smp_store_release() and smp_load_acquire() in addition to the + obvious lock acquisitions and releases. + +RM-broken.litmus + Demonstrates problems with "roach motel" locking, where code is + freely moved into lock-based critical sections. This example also + shows how to use the "filter" clause to discard executions that + would be excluded by other code not modeled in the litmus test. + Note also that this "roach motel" optimization is emulated by + physically moving P1()'s two reads from x under the lock. + + What is a roach motel? This is from an old advertisement for + a cockroach trap, much later featured in one of the "Men in + Black" movies. "The roaches check in. They don't check out." + +RM-fixed.litmus + The counterpart to RM-broken.litmus, showing P0()'s two loads from + x safely outside of the critical section. + + RCU (/rcu directory) -------------------- |