mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
5c587f9b9c
This is a revert of commit 1947bfcf81 ("tools/memory-model: Add types
to litmus tests") with conflict resolutions.
klitmus7 [1] is aware of default types of "int" and "int*".
It accepts litmus tests for herd7 without extra type info unless
non-"int" variables are referenced by an "exists", "locations",
or "filter" directive.
[1]: Tested with klitmus7 versions 7.49 or later.
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
39 lines
784 B
Text
39 lines
784 B
Text
C ISA2+pooncerelease+poacquirerelease+poacquireonce
|
|
|
|
(*
|
|
* Result: Never
|
|
*
|
|
* This litmus test demonstrates that a release-acquire chain suffices
|
|
* to order P0()'s initial write against P2()'s final read. The reason
|
|
* that the release-acquire chain suffices is because in all but one
|
|
* case (P2() to P0()), each process reads from the preceding process's
|
|
* write. In memory-model-speak, there is only one non-reads-from
|
|
* (AKA non-rf) link, so release-acquire is all that is needed.
|
|
*)
|
|
|
|
{}
|
|
|
|
P0(int *x, int *y)
|
|
{
|
|
WRITE_ONCE(*x, 1);
|
|
smp_store_release(y, 1);
|
|
}
|
|
|
|
P1(int *y, int *z)
|
|
{
|
|
int r0;
|
|
|
|
r0 = smp_load_acquire(y);
|
|
smp_store_release(z, 1);
|
|
}
|
|
|
|
P2(int *x, int *z)
|
|
{
|
|
int r0;
|
|
int r1;
|
|
|
|
r0 = smp_load_acquire(z);
|
|
r1 = READ_ONCE(*x);
|
|
}
|
|
|
|
exists (1:r0=1 /\ 2:r0=1 /\ 2:r1=0)
|