diff options
| author | Andrea Parri <[email protected]> | 2019-06-29 23:10:44 +0200 |
|---|---|---|
| committer | Paul E. McKenney <[email protected]> | 2019-08-09 10:28:57 -0700 |
| commit | 6738ff85c3ee8073d5b030cb26241d0009d4ce29 (patch) | |
| tree | 925debdeae5d0d6ff762c0fbfa881823db134723 /tools/memory-model/README | |
| parent | 6240973e5661a83df24e35a9a9c2013496931e2b (diff) | |
tools/memory-model: Update the informal documentation
The formal memory consistency model has added support for plain accesses
(and data races). While updating the informal documentation to describe
this addition to the model is highly desirable and important future work,
update the informal documentation to at least acknowledge such addition.
Signed-off-by: Andrea Parri <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: David Howells <[email protected]>
Cc: Jade Alglave <[email protected]>
Cc: Luc Maranget <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Akira Yokosawa <[email protected]>
Cc: Daniel Lustig <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Acked-by: Alan Stern <[email protected]>
Diffstat (limited to 'tools/memory-model/README')
| -rw-r--r-- | tools/memory-model/README | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/tools/memory-model/README b/tools/memory-model/README index 2b87f3971548..fc07b52f2028 100644 --- a/tools/memory-model/README +++ b/tools/memory-model/README @@ -167,15 +167,15 @@ scripts Various scripts, see scripts/README. LIMITATIONS =========== -The Linux-kernel memory model has the following limitations: - -1. Compiler optimizations are not modeled. Of course, the use - of READ_ONCE() and WRITE_ONCE() limits the compiler's ability - to optimize, but there is Linux-kernel code that uses bare C - memory accesses. Handling this code is on the to-do list. - For more information, see Documentation/explanation.txt (in - particular, the "THE PROGRAM ORDER RELATION: po AND po-loc" - and "A WARNING" sections). +The Linux-kernel memory model (LKMM) has the following limitations: + +1. Compiler optimizations are not accurately modeled. Of course, + the use of READ_ONCE() and WRITE_ONCE() limits the compiler's + ability to optimize, but under some circumstances it is possible + for the compiler to undermine the memory model. For more + information, see Documentation/explanation.txt (in particular, + the "THE PROGRAM ORDER RELATION: po AND po-loc" and "A WARNING" + sections). Note that this limitation in turn limits LKMM's ability to accurately model address, control, and data dependencies. |