diff options
author | Alan Jenkins <alan-jenkins@tuffmail.co.uk> | 2008-09-28 12:02:44 +0100 |
---|---|---|
committer | Kay Sievers <kay.sievers@vrfy.org> | 2008-09-28 14:11:47 +0200 |
commit | 41b7a00922bdb1a501cbf2e39282fe64bb94cb6d (patch) | |
tree | 2c212da9aa9a2e773a344f11fb9b0de2889aed3f /udev | |
parent | 669ed8675f7a8bc3987ad501d11f7623b70698e6 (diff) |
avoid repeated scans for goto targets (udev_iter_find_label)
The scans are now performed up-front at parse-time, instead of being
repeated for each event at run-time.
Cachegrind reports a 5% reduction in cpu cycles
(excluding the time spent in-kernel).
Diffstat (limited to 'udev')
-rw-r--r-- | udev/udev_rules.c | 4 | ||||
-rw-r--r-- | udev/udev_rules.h | 3 | ||||
-rw-r--r-- | udev/udev_rules_parse.c | 50 |
3 files changed, 45 insertions, 12 deletions
diff --git a/udev/udev_rules.c b/udev/udev_rules.c index d4dcb06801..9c37571fb0 100644 --- a/udev/udev_rules.c +++ b/udev/udev_rules.c @@ -1529,7 +1529,7 @@ int udev_rules_get_name(struct udev_rules *rules, struct udevice *udevice) if (rule->goto_label.operation != KEY_OP_UNSET) { dbg(udevice->udev, "moving forward to label '%s'\n", key_val(rule, &rule->goto_label)); - udev_rules_iter_label(&iter, key_val(rule, &rule->goto_label)); + udev_rules_iter_goto(&iter, rule->goto_rule_off); } } } @@ -1609,7 +1609,7 @@ int udev_rules_get_run(struct udev_rules *rules, struct udevice *udevice) if (rule->goto_label.operation != KEY_OP_UNSET) { dbg(udevice->udev, "moving forward to label '%s'\n", key_val(rule, &rule->goto_label)); - udev_rules_iter_label(&iter, key_val(rule, &rule->goto_label)); + udev_rules_iter_goto(&iter, rule->goto_rule_off); } } } diff --git a/udev/udev_rules.h b/udev/udev_rules.h index 02685e1834..af96b8119b 100644 --- a/udev/udev_rules.h +++ b/udev/udev_rules.h @@ -84,6 +84,7 @@ struct udev_rule { struct key wait_for; struct key label; struct key goto_label; + size_t goto_rule_off; struct key name; struct key symlink; @@ -122,7 +123,7 @@ extern void udev_rules_cleanup(struct udev_rules *rules); extern void udev_rules_iter_init(struct udev_rules_iter *iter, struct udev_rules *rules); extern struct udev_rule *udev_rules_iter_next(struct udev_rules_iter *iter); -extern struct udev_rule *udev_rules_iter_label(struct udev_rules_iter *iter, const char *label); +extern struct udev_rule *udev_rules_iter_goto(struct udev_rules_iter *iter, size_t rule_off); extern int udev_rules_get_name(struct udev_rules *rules, struct udevice *udev); extern int udev_rules_get_run(struct udev_rules *rules, struct udevice *udev); diff --git a/udev/udev_rules_parse.c b/udev/udev_rules_parse.c index 229096c8d7..5a76889c84 100644 --- a/udev/udev_rules_parse.c +++ b/udev/udev_rules_parse.c @@ -58,29 +58,40 @@ struct udev_rule *udev_rules_iter_next(struct udev_rules_iter *iter) return rule; } -struct udev_rule *udev_rules_iter_label(struct udev_rules_iter *iter, const char *label) +struct udev_rule *udev_rules_iter_goto(struct udev_rules_iter *iter, size_t rule_off) +{ + struct udev_rules *rules = iter->rules; + struct udev_rule *rule; + + dbg(rules->udev "current=%zi\n", iter->current); + iter->current = rule_off; + rule = (struct udev_rule *) (rules->buf + iter->current); + + return rule; +} + +static size_t find_label(const struct udev_rules_iter *iter, const char *label) { struct udev_rule *rule; struct udev_rules *rules = iter->rules; - size_t start = iter->current; + size_t current = iter->current; next: - dbg(rules->udev, "current=%zi\n", iter->current); - if (iter->current >= rules->bufsize) { + dbg(rules->udev, "current=%zi\n", current); + if (current >= rules->bufsize) { err(rules->udev, "LABEL='%s' not found, GOTO will be ignored\n", label); - iter->current = start; - return NULL; + return iter->current; } - rule = (struct udev_rule *) (rules->buf + iter->current); + rule = (struct udev_rule *) (rules->buf + current); if (strcmp(&rule->buf[rule->label.val_off], label) != 0) { dbg(rules->udev, "moving forward, looking for label '%s'\n", label); - iter->current += sizeof(struct udev_rule) + rule->bufsize; + current += sizeof(struct udev_rule) + rule->bufsize; goto next; } dbg(rules->udev, "found label '%s'\n", label); - return rule; + return current; } static int get_key(struct udev_rules *rules, char **line, char **key, enum key_operation *operation, char **value) @@ -674,6 +685,11 @@ static int parse_file(struct udev_rules *rules, const char *filename) size_t cur; size_t count; int retval = 0; + size_t start; + struct udev_rule *rule; + struct udev_rules_iter iter; + + start = rules->bufsize; if (file_map(filename, &buf, &bufsize) != 0) { err(rules->udev, "can't open '%s' as rules file: %s\n", filename, strerror(errno)); @@ -722,6 +738,22 @@ static int parse_file(struct udev_rules *rules, const char *filename) add_to_rules(rules, line, filename, lineno); } + /* Compute all goto targets within this file */ + udev_rules_iter_init(&iter, rules); + udev_rules_iter_goto(&iter, start); + while((rule = udev_rules_iter_next(&iter))) { + if (rule->goto_label.operation != KEY_OP_UNSET) { + char *goto_label = &rule->buf[rule->goto_label.val_off]; + + dbg(rules->udev, "resolving goto label '%s'", goto_label); + rule->goto_rule_off = find_label(&iter, goto_label); + if (rule->goto_rule_off == iter.current) { + err(rules->udev, "goto nonexistent label '%s' in '%s'", + goto_label, filename); + } + } + } + file_unmap(buf, bufsize); return retval; } |