[PATCH 2/3] vmevent: Factor vmevent_match_attr() out of vmevent_match()

From: Anton Vorontsov
Date: Thu Oct 04 2012 - 06:24:29 EST


Soon we'll use this new function for other code; plus this makes code less
indented.

Signed-off-by: Anton Vorontsov <anton.vorontsov@xxxxxxxxxx>
---
mm/vmevent.c | 107 +++++++++++++++++++++++++++++++----------------------------
1 file changed, 57 insertions(+), 50 deletions(-)

diff --git a/mm/vmevent.c b/mm/vmevent.c
index 39ef786..d434c11 100644
--- a/mm/vmevent.c
+++ b/mm/vmevent.c
@@ -77,6 +77,59 @@ enum {
VMEVENT_ATTR_STATE_VALUE_WAS_GT = (1UL << 31),
};

+static bool vmevent_match_attr(struct vmevent_attr *attr, u64 value)
+{
+ 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;
+ bool edge = state & VMEVENT_ATTR_STATE_EDGE_TRIGGER;
+ u32 was_lt_mask = VMEVENT_ATTR_STATE_VALUE_WAS_LT;
+ u32 was_gt_mask = VMEVENT_ATTR_STATE_VALUE_WAS_GT;
+ 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 (!state)
+ return false;
+
+ if (!attr_lt && !attr_gt && !attr_eq)
+ return false;
+
+ if (((attr_lt && lt) || (attr_gt && gt) || (attr_eq && eq)) && !edge)
+ return true;
+
+ if (attr_eq && eq && was_eq) {
+ return false;
+ } 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;
+ if (attr_lt)
+ ret = true;
+ } else if (gt) {
+ state |= was_gt_mask;
+ state &= ~was_lt_mask;
+ if (attr_gt)
+ ret = true;
+ }
+
+ attr->state = state;
+ return ret;
+}
+
static bool vmevent_match(struct vmevent_watch *watch)
{
struct vmevent_config *config = &watch->config;
@@ -84,57 +137,11 @@ static bool vmevent_match(struct vmevent_watch *watch)

for (i = 0; i < config->counter; i++) {
struct vmevent_attr *attr = &config->attrs[i];
- 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;
+ u64 val;

- if (attr_lt || attr_gt || attr_eq) {
- bool edge = state & VMEVENT_ATTR_STATE_EDGE_TRIGGER;
- 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) ||
- (attr_eq && eq)) && !edge)
- return true;
-
- if (attr_eq && eq && was_eq) {
- return false;
- } 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;
- if (attr_lt)
- ret = true;
- } else if (gt) {
- state |= was_gt_mask;
- state &= ~was_lt_mask;
- if (attr_gt)
- ret = true;
- }
-
- attr->state = state;
- return ret;
- }
+ val = vmevent_sample_attr(watch, attr);
+ if (vmevent_match_attr(attr, val))
+ return true;
}

return false;
--
1.7.12.1

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