On Thu, Oct 10, 2024 at 05:38:34PM +0200, Frederic Weisbecker wrote:
> Le Wed, Oct 09, 2024 at 11:07:19AM -0700, Paul E. McKenney a écrit :
> > This commit creates a new srcu-lite option for the refscale.scale_type
> > module parameter that selects srcu_read_lock_lite() and
> > srcu_read_unlock_lite().
> >
> > Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
> > Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
> > Cc: Andrii Nakryiko <andrii@xxxxxxxxxx>
> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
> > Cc: <bpf@xxxxxxxxxxxxxxx>
>
> This one does not apply cleanly. I assume there is some dependency to another
> branch?
Quite possibly, since I made a stack rather than a set of branches.
I will branchify later today, make some updates from feedback, and
resend.
Apologies for the hassle!
Thanx, Paul
> Thanks.
>
> > ---
> > kernel/rcu/refscale.c | 51 +++++++++++++++++++++++++++++++++----------
> > 1 file changed, 40 insertions(+), 11 deletions(-)
> >
> > diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c
> > index be66e5a67ee19..897d5b5494949 100644
> > --- a/kernel/rcu/refscale.c
> > +++ b/kernel/rcu/refscale.c
> > @@ -216,6 +216,36 @@ static const struct ref_scale_ops srcu_ops = {
> > .name = "srcu"
> > };
> >
> > +static void srcu_lite_ref_scale_read_section(const int nloops)
> > +{
> > + int i;
> > + int idx;
> > +
> > + for (i = nloops; i >= 0; i--) {
> > + idx = srcu_read_lock_lite(srcu_ctlp);
> > + srcu_read_unlock_lite(srcu_ctlp, idx);
> > + }
> > +}
> > +
> > +static void srcu_lite_ref_scale_delay_section(const int nloops, const int udl, const int ndl)
> > +{
> > + int i;
> > + int idx;
> > +
> > + for (i = nloops; i >= 0; i--) {
> > + idx = srcu_read_lock_lite(srcu_ctlp);
> > + un_delay(udl, ndl);
> > + srcu_read_unlock_lite(srcu_ctlp, idx);
> > + }
> > +}
> > +
> > +static const struct ref_scale_ops srcu_lite_ops = {
> > + .init = rcu_sync_scale_init,
> > + .readsection = srcu_lite_ref_scale_read_section,
> > + .delaysection = srcu_lite_ref_scale_delay_section,
> > + .name = "srcu-lite"
> > +};
> > +
> > #ifdef CONFIG_TASKS_RCU
> >
> > // Definitions for RCU Tasks ref scale testing: Empty read markers.
> > @@ -1133,27 +1163,26 @@ ref_scale_init(void)
> > long i;
> > int firsterr = 0;
> > static const struct ref_scale_ops *scale_ops[] = {
> > - &rcu_ops, &srcu_ops, RCU_TRACE_OPS RCU_TASKS_OPS &refcnt_ops, &rwlock_ops,
> > - &rwsem_ops, &lock_ops, &lock_irq_ops, &acqrel_ops, &sched_clock_ops, &clock_ops,
> > - &jiffies_ops, &typesafe_ref_ops, &typesafe_lock_ops, &typesafe_seqlock_ops,
> > + &rcu_ops, &srcu_ops, &srcu_lite_ops, RCU_TRACE_OPS RCU_TASKS_OPS
> > + &refcnt_ops, &rwlock_ops, &rwsem_ops, &lock_ops, &lock_irq_ops, &acqrel_ops,
> > + &sched_clock_ops, &clock_ops, &jiffies_ops, &typesafe_ref_ops, &typesafe_lock_ops,
> > + &typesafe_seqlock_ops,
> > };
> >
> > if (!torture_init_begin(scale_type, verbose))
> > return -EBUSY;
> >
> > for (i = 0; i < ARRAY_SIZE(scale_ops); i++) {
> > - cur_ops = scale_ops[i];
> > - if (strcmp(scale_type, cur_ops->name) == 0)
> > + cur_ops = scale_ops[i]; if (strcmp(scale_type,
> > + cur_ops->name) == 0)
> > break;
> > }
> > if (i == ARRAY_SIZE(scale_ops)) {
> > - pr_alert("rcu-scale: invalid scale type: \"%s\"\n", scale_type);
> > - pr_alert("rcu-scale types:");
> > - for (i = 0; i < ARRAY_SIZE(scale_ops); i++)
> > + pr_alert("rcu-scale: invalid scale type: \"%s\"\n",
> > + scale_type); pr_alert("rcu-scale types:"); for (i = 0;
> > + i < ARRAY_SIZE(scale_ops); i++)
> > pr_cont(" %s", scale_ops[i]->name);
> > - pr_cont("\n");
> > - firsterr = -EINVAL;
> > - cur_ops = NULL;
> > + pr_cont("\n"); firsterr = -EINVAL; cur_ops = NULL;
> > goto unwind;
> > }
> > if (cur_ops->init)
> > --
> > 2.40.1
> >
