On 5/16/22 11:35, Chen Wandun wrote:
> Nowadays, psi events are triggered when stall time exceed
> stall threshold, but no any different between these events.
>
> Actually, events can be divide into multi level, each level
> represent a different stall pressure, that is help to identify
> pressure information more accurately.
>
> echo "some 150000 350000 1000000" > /proc/pressure/memory would
This breaks the old ABI. And why you need this new function?
Thanks
> add [150ms, 350ms) threshold for partial memory stall measured
> within 1sec time window.
>
> Signed-off-by: Chen Wandun <chenwandun@xxxxxxxxxx>
> ---
> include/linux/psi_types.h | 3 ++-
> kernel/sched/psi.c | 19 +++++++++++++------
> 2 files changed, 15 insertions(+), 7 deletions(-)
>
> diff --git a/include/linux/psi_types.h b/include/linux/psi_types.h
> index c7fe7c089718..2b1393c8bf90 100644
> --- a/include/linux/psi_types.h
> +++ b/include/linux/psi_types.h
> @@ -119,7 +119,8 @@ struct psi_trigger {
> enum psi_states state;
>
> /* User-spacified threshold in ns */
> - u64 threshold;
> + u64 min_threshold;
> + u64 max_threshold;
>
> /* List node inside triggers list */
> struct list_head node;
> diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
> index 6f9533c95b0a..17dd233b533a 100644
> --- a/kernel/sched/psi.c
> +++ b/kernel/sched/psi.c
> @@ -541,7 +541,7 @@ static u64 update_triggers(struct psi_group *group, u64 now)
>
> /* Calculate growth since last update */
> growth = window_update(&t->win, now, total[t->state]);
> - if (growth < t->threshold)
> + if (growth < t->min_threshold || growth >= t->max_threshold)
> continue;
>
> t->pending_event = true;
> @@ -1087,15 +1087,18 @@ struct psi_trigger *psi_trigger_create(struct psi_group *group,
> {
> struct psi_trigger *t;
> enum psi_states state;
> - u32 threshold_us;
> + u32 min_threshold_us;
> + u32 max_threshold_us;
> u32 window_us;
>
> if (static_branch_likely(&psi_disabled))
> return ERR_PTR(-EOPNOTSUPP);
>
> - if (sscanf(buf, "some %u %u", &threshold_us, &window_us) == 2)
> + if (sscanf(buf, "some %u %u %u", &min_threshold_us,
> + &max_threshold_us, &window_us) == 3)
> state = PSI_IO_SOME + res * 2;
> - else if (sscanf(buf, "full %u %u", &threshold_us, &window_us) == 2)
> + else if (sscanf(buf, "full %u %u %u", &min_threshold_us,
> + &max_threshold_us, &window_us) == 3)
> state = PSI_IO_FULL + res * 2;
> else
> return ERR_PTR(-EINVAL);
> @@ -1107,8 +1110,11 @@ struct psi_trigger *psi_trigger_create(struct psi_group *group,
> window_us > WINDOW_MAX_US)
> return ERR_PTR(-EINVAL);
>
> + if (min_threshold_us >= max_threshold_us)
> + return ERR_PTR(-EINVAL);
> +
> /* Check threshold */
> - if (threshold_us == 0 || threshold_us > window_us)
> + if (max_threshold_us > window_us)
> return ERR_PTR(-EINVAL);
>
> t = kmalloc(sizeof(*t), GFP_KERNEL);
> @@ -1117,7 +1123,8 @@ struct psi_trigger *psi_trigger_create(struct psi_group *group,
>
> t->group = group;
> t->state = state;
> - t->threshold = threshold_us * NSEC_PER_USEC;
> + t->min_threshold = min_threshold_us * NSEC_PER_USEC;
> + t->max_threshold = max_threshold_us * NSEC_PER_USEC;
> t->win.size = window_us * NSEC_PER_USEC;
> window_reset(&t->win, 0, 0, 0);
>
