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>
38 lines
704 B
Plaintext
38 lines
704 B
Plaintext
C RCU+sync+read
|
|
|
|
(*
|
|
* Result: Never
|
|
*
|
|
* This litmus test demonstrates that after a grace period, an RCU updater always
|
|
* sees all stores done in prior RCU read-side critical sections. Such
|
|
* read-side critical sections would have ended before the grace period ended.
|
|
*
|
|
* This is one implication of the RCU grace-period guarantee, which says (among
|
|
* other things) that an RCU read-side critical section cannot span a grace period.
|
|
*)
|
|
|
|
{
|
|
int x = 0;
|
|
int y = 0;
|
|
}
|
|
|
|
P0(int *x, int *y)
|
|
{
|
|
rcu_read_lock();
|
|
WRITE_ONCE(*x, 1);
|
|
WRITE_ONCE(*y, 1);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
P1(int *x, int *y)
|
|
{
|
|
int r0;
|
|
int r1;
|
|
|
|
r0 = READ_ONCE(*x);
|
|
synchronize_rcu();
|
|
r1 = READ_ONCE(*y);
|
|
}
|
|
|
|
exists (1:r0=1 /\ 1:r1=0)
|