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
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);
--
2.25.1
