mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-30 08:02:30 +00:00
rcu: Add READ_ONCE() to rcu_do_batch() access to rcu_resched_ns
Given that sysfs can change the value of rcu_resched_ns at any time, this commit adds a READ_ONCE() to the sole access to that variable. While in the area, this commit also adds bounds checking, clamping the value to at least a millisecond, but no longer than a second. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit is contained in:
parent
b5374b2df0
commit
a2b354b995
1 changed files with 6 additions and 2 deletions
|
@ -2394,8 +2394,12 @@ static void rcu_do_batch(struct rcu_data *rdp)
|
|||
div = READ_ONCE(rcu_divisor);
|
||||
div = div < 0 ? 7 : div > sizeof(long) * 8 - 2 ? sizeof(long) * 8 - 2 : div;
|
||||
bl = max(rdp->blimit, pending >> div);
|
||||
if (unlikely(bl > 100))
|
||||
tlimit = local_clock() + rcu_resched_ns;
|
||||
if (unlikely(bl > 100)) {
|
||||
long rrn = READ_ONCE(rcu_resched_ns);
|
||||
|
||||
rrn = rrn < NSEC_PER_MSEC ? NSEC_PER_MSEC : rrn > NSEC_PER_SEC ? NSEC_PER_SEC : rrn;
|
||||
tlimit = local_clock() + rrn;
|
||||
}
|
||||
trace_rcu_batch_start(rcu_state.name,
|
||||
rcu_segcblist_n_cbs(&rdp->cblist), bl);
|
||||
rcu_segcblist_extract_done_cbs(&rdp->cblist, &rcl);
|
||||
|
|
Loading…
Reference in a new issue