This complements GT and LT, making it possible to combine GE and LE operators. We'll use it for blended attributes: the special attributes will return either 0 or <threshold>, so to make two-way notifications we will pass LT | EQ bits.
Signed-off-by: Anton Vorontsov anton.vorontsov@linaro.org --- include/linux/vmevent.h | 6 +++++- mm/vmevent.c | 22 +++++++++++++++------- 2 files changed, 20 insertions(+), 8 deletions(-)
diff --git a/include/linux/vmevent.h b/include/linux/vmevent.h index ca97cf0..aae0d24 100644 --- a/include/linux/vmevent.h +++ b/include/linux/vmevent.h @@ -27,9 +27,13 @@ enum { */ VMEVENT_ATTR_STATE_VALUE_GT = (1UL << 1), /* + * Sample value is equal to user-specified value + */ + VMEVENT_ATTR_STATE_VALUE_EQ = (1UL << 2), + /* * One-shot mode. */ - VMEVENT_ATTR_STATE_ONE_SHOT = (1UL << 2), + VMEVENT_ATTR_STATE_ONE_SHOT = (1UL << 3),
/* Saved state, used internally by the kernel for one-shot mode. */ __VMEVENT_ATTR_STATE_VALUE_WAS_LT = (1UL << 30), diff --git a/mm/vmevent.c b/mm/vmevent.c index 47ed448..9f1520b 100644 --- a/mm/vmevent.c +++ b/mm/vmevent.c @@ -87,28 +87,39 @@ static bool vmevent_match(struct vmevent_watch *watch) u32 state = attr->state; bool attr_lt = state & VMEVENT_ATTR_STATE_VALUE_LT; bool attr_gt = state & VMEVENT_ATTR_STATE_VALUE_GT; + bool attr_eq = state & VMEVENT_ATTR_STATE_VALUE_EQ;
if (!state) continue;
- if (attr_lt || attr_gt) { + if (attr_lt || attr_gt || attr_eq) { bool one_shot = state & VMEVENT_ATTR_STATE_ONE_SHOT; u32 was_lt_mask = __VMEVENT_ATTR_STATE_VALUE_WAS_LT; u32 was_gt_mask = __VMEVENT_ATTR_STATE_VALUE_WAS_GT; u64 value = vmevent_sample_attr(watch, attr); bool lt = value < attr->value; bool gt = value > attr->value; + bool eq = value == attr->value; bool was_lt = state & was_lt_mask; bool was_gt = state & was_gt_mask; + bool was_eq = was_lt && was_gt; bool ret = false;
- if (((attr_lt && lt) || (attr_gt && gt)) && !one_shot) + if (((attr_lt && lt) || (attr_gt && gt) || + (attr_eq && eq)) && !one_shot) return true;
- if (attr_lt && lt && was_lt) { + if (attr_eq && eq && was_eq) { return false; - } else if (attr_gt && gt && was_gt) { + } else if (attr_lt && lt && was_lt && !was_eq) { return false; + } else if (attr_gt && gt && was_gt && !was_eq) { + return false; + } else if (eq) { + state |= was_lt_mask; + state |= was_gt_mask; + if (attr_eq) + ret = true; } else if (lt) { state |= was_lt_mask; state &= ~was_gt_mask; @@ -119,9 +130,6 @@ static bool vmevent_match(struct vmevent_watch *watch) state &= ~was_lt_mask; if (attr_gt) ret = true; - } else { - state &= ~was_lt_mask; - state &= ~was_gt_mask; }
attr->state = state;