Commit 395e73bd authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

srcu: Add NUM_ACTIVE_SRCU_POLL_OLDSTATE 



This commit adds NUM_ACTIVE_SRCU_POLL_OLDSTATE, which gives the maximum
number of distinct return values from get_state_synchronize_rcu()
that can, at a given point in time, correspond to not-completed SRCU
grace periods.

Reported-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
Closes: https://lore.kernel.org/all/irycqy4sinjdgm2hkyix2bffunpcmuwgeufsx6nlljvqme3wiu@ify3zdnrmzph/


Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 1613e604

include/linux/srcu.h

+4 −0
Original line number Diff line number Diff line
@@ -61,6 +61,10 @@ unsigned long get_state_synchronize_srcu(struct srcu_struct *ssp); 
unsigned long start_poll_synchronize_srcu(struct srcu_struct *ssp);

bool poll_state_synchronize_srcu(struct srcu_struct *ssp, unsigned long cookie);



// Maximum number of unsigned long values corresponding to

// not-yet-completed SRCU grace periods.

#define NUM_ACTIVE_SRCU_POLL_OLDSTATE 2



#ifdef CONFIG_NEED_SRCU_NMI_SAFE

int __srcu_read_lock_nmisafe(struct srcu_struct *ssp) __acquires(ssp);

void __srcu_read_unlock_nmisafe(struct srcu_struct *ssp, int idx) __releases(ssp);