Greg Kroah-Hartman
598cf27219
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
35 lines
498 B
Plaintext
35 lines
498 B
Plaintext
C cmpxchg-fail-unordered-1
|
|
|
|
(*
|
|
* Result: Sometimes
|
|
*
|
|
* Demonstrate that a failing cmpxchg() operation does not act as a
|
|
* full barrier. (In contrast, a successful cmpxchg() does act as a
|
|
* full barrier.)
|
|
*)
|
|
|
|
{}
|
|
|
|
P0(int *x, int *y, int *z)
|
|
{
|
|
int r0;
|
|
int r1;
|
|
|
|
WRITE_ONCE(*x, 1);
|
|
r1 = cmpxchg(z, 1, 0);
|
|
r0 = READ_ONCE(*y);
|
|
}
|
|
|
|
P1(int *x, int *y, int *z)
|
|
{
|
|
int r0;
|
|
int r1;
|
|
|
|
WRITE_ONCE(*y, 1);
|
|
r1 = cmpxchg(z, 1, 0);
|
|
r0 = READ_ONCE(*x);
|
|
}
|
|
|
|
locations[0:r1;1:r1]
|
|
exists (0:r0=0 /\ 1:r0=0)
|