#include <asm/uaccess.h>
#include <asm/system.h>
-#include <asm/bitops.h>
+#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/init.h>
+#include <linux/rbtree.h>
+#include <linux/slab.h>
#include <net/sock.h>
#include <net/gen_stats.h>
NOTES.
- * The stored value for avbps is scaled by 2^5, so that maximal
- rate is ~1Gbit, avpps is scaled by 2^10.
-
+ * avbps is scaled by 2^5, avpps is scaled by 2^10.
+ * both values are reported as 32 bit unsigned values. bps can
+ overflow for fast links : max speed being 34360Mbit/sec
* Minimal interval is HZ/4=250msec (it is the greatest common divisor
for HZ=100 and HZ=1024 8)), maximal interval
is (HZ*2^EST_MAX_INTERVAL)/4 = 8sec. Shorter intervals
struct gen_estimator
{
- struct gen_estimator *next;
- struct gnet_stats_basic *bstats;
+ struct list_head list;
+ struct gnet_stats_basic_packed *bstats;
struct gnet_stats_rate_est *rate_est;
spinlock_t *stats_lock;
- unsigned interval;
int ewma_log;
u64 last_bytes;
+ u64 avbps;
u32 last_packets;
u32 avpps;
- u32 avbps;
+ struct rcu_head e_rcu;
+ struct rb_node node;
};
struct gen_estimator_head
{
struct timer_list timer;
- struct gen_estimator *list;
+ struct list_head list;
};
static struct gen_estimator_head elist[EST_MAX_INTERVAL+1];
-/* Estimator array lock */
+/* Protects against NULL dereference */
static DEFINE_RWLOCK(est_lock);
+/* Protects against soft lockup during large deletion */
+static struct rb_root est_root = RB_ROOT;
+
static void est_timer(unsigned long arg)
{
int idx = (int)arg;
struct gen_estimator *e;
- read_lock(&est_lock);
- for (e = elist[idx].list; e; e = e->next) {
+ rcu_read_lock();
+ list_for_each_entry_rcu(e, &elist[idx].list, list) {
u64 nbytes;
+ u64 brate;
u32 npackets;
u32 rate;
spin_lock(e->stats_lock);
+ read_lock(&est_lock);
+ if (e->bstats == NULL)
+ goto skip;
+
nbytes = e->bstats->bytes;
npackets = e->bstats->packets;
- rate = (nbytes - e->last_bytes)<<(7 - idx);
+ brate = (nbytes - e->last_bytes)<<(7 - idx);
e->last_bytes = nbytes;
- e->avbps += ((long)rate - (long)e->avbps) >> e->ewma_log;
+ e->avbps += (brate >> e->ewma_log) - (e->avbps >> e->ewma_log);
e->rate_est->bps = (e->avbps+0xF)>>5;
rate = (npackets - e->last_packets)<<(12 - idx);
e->last_packets = npackets;
- e->avpps += ((long)rate - (long)e->avpps) >> e->ewma_log;
+ e->avpps += (rate >> e->ewma_log) - (e->avpps >> e->ewma_log);
e->rate_est->pps = (e->avpps+0x1FF)>>10;
+skip:
+ read_unlock(&est_lock);
spin_unlock(e->stats_lock);
}
- mod_timer(&elist[idx].timer, jiffies + ((HZ<<idx)/4));
- read_unlock(&est_lock);
+ if (!list_empty(&elist[idx].list))
+ mod_timer(&elist[idx].timer, jiffies + ((HZ/4) << idx));
+ rcu_read_unlock();
+}
+
+static void gen_add_node(struct gen_estimator *est)
+{
+ struct rb_node **p = &est_root.rb_node, *parent = NULL;
+
+ while (*p) {
+ struct gen_estimator *e;
+
+ parent = *p;
+ e = rb_entry(parent, struct gen_estimator, node);
+
+ if (est->bstats > e->bstats)
+ p = &parent->rb_right;
+ else
+ p = &parent->rb_left;
+ }
+ rb_link_node(&est->node, parent, p);
+ rb_insert_color(&est->node, &est_root);
+}
+
+static
+struct gen_estimator *gen_find_node(const struct gnet_stats_basic_packed *bstats,
+ const struct gnet_stats_rate_est *rate_est)
+{
+ struct rb_node *p = est_root.rb_node;
+
+ while (p) {
+ struct gen_estimator *e;
+
+ e = rb_entry(p, struct gen_estimator, node);
+
+ if (bstats > e->bstats)
+ p = p->rb_right;
+ else if (bstats < e->bstats || rate_est != e->rate_est)
+ p = p->rb_left;
+ else
+ return e;
+ }
+ return NULL;
}
/**
* configuration TLV is created. Upon each interval, the latest statistics
* will be read from &bstats and the estimated rate will be stored in
* &rate_est with the statistics lock grabed during this period.
- *
+ *
* Returns 0 on success or a negative error code.
+ *
+ * NOTE: Called under rtnl_mutex
*/
-int gen_new_estimator(struct gnet_stats_basic *bstats,
- struct gnet_stats_rate_est *rate_est, spinlock_t *stats_lock, struct rtattr *opt)
+int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
+ struct gnet_stats_rate_est *rate_est,
+ spinlock_t *stats_lock,
+ struct nlattr *opt)
{
struct gen_estimator *est;
- struct gnet_estimator *parm = RTA_DATA(opt);
+ struct gnet_estimator *parm = nla_data(opt);
+ int idx;
- if (RTA_PAYLOAD(opt) < sizeof(*parm))
+ if (nla_len(opt) < sizeof(*parm))
return -EINVAL;
if (parm->interval < -2 || parm->interval > 3)
return -EINVAL;
- est = kmalloc(sizeof(*est), GFP_KERNEL);
+ est = kzalloc(sizeof(*est), GFP_KERNEL);
if (est == NULL)
return -ENOBUFS;
- memset(est, 0, sizeof(*est));
- est->interval = parm->interval + 2;
+ idx = parm->interval + 2;
est->bstats = bstats;
est->rate_est = rate_est;
est->stats_lock = stats_lock;
est->last_packets = bstats->packets;
est->avpps = rate_est->pps<<10;
- est->next = elist[est->interval].list;
- if (est->next == NULL) {
- init_timer(&elist[est->interval].timer);
- elist[est->interval].timer.data = est->interval;
- elist[est->interval].timer.expires = jiffies + ((HZ<<est->interval)/4);
- elist[est->interval].timer.function = est_timer;
- add_timer(&elist[est->interval].timer);
+ if (!elist[idx].timer.function) {
+ INIT_LIST_HEAD(&elist[idx].list);
+ setup_timer(&elist[idx].timer, est_timer, idx);
}
- write_lock_bh(&est_lock);
- elist[est->interval].list = est;
- write_unlock_bh(&est_lock);
+
+ if (list_empty(&elist[idx].list))
+ mod_timer(&elist[idx].timer, jiffies + ((HZ/4) << idx));
+
+ list_add_rcu(&est->list, &elist[idx].list);
+ gen_add_node(est);
+
return 0;
}
+EXPORT_SYMBOL(gen_new_estimator);
+
+static void __gen_kill_estimator(struct rcu_head *head)
+{
+ struct gen_estimator *e = container_of(head,
+ struct gen_estimator, e_rcu);
+ kfree(e);
+}
/**
* gen_kill_estimator - remove a rate estimator
* @bstats: basic statistics
* @rate_est: rate estimator statistics
*
- * Removes the rate estimator specified by &bstats and &rate_est
- * and deletes the timer.
+ * Removes the rate estimator specified by &bstats and &rate_est.
+ *
+ * NOTE: Called under rtnl_mutex
*/
-void gen_kill_estimator(struct gnet_stats_basic *bstats,
- struct gnet_stats_rate_est *rate_est)
+void gen_kill_estimator(struct gnet_stats_basic_packed *bstats,
+ struct gnet_stats_rate_est *rate_est)
{
- int idx;
- struct gen_estimator *est, **pest;
-
- for (idx=0; idx <= EST_MAX_INTERVAL; idx++) {
- int killed = 0;
- pest = &elist[idx].list;
- while ((est=*pest) != NULL) {
- if (est->rate_est != rate_est || est->bstats != bstats) {
- pest = &est->next;
- continue;
- }
-
- write_lock_bh(&est_lock);
- *pest = est->next;
- write_unlock_bh(&est_lock);
-
- kfree(est);
- killed++;
- }
- if (killed && elist[idx].list == NULL)
- del_timer(&elist[idx].timer);
+ struct gen_estimator *e;
+
+ while ((e = gen_find_node(bstats, rate_est))) {
+ rb_erase(&e->node, &est_root);
+
+ write_lock_bh(&est_lock);
+ e->bstats = NULL;
+ write_unlock_bh(&est_lock);
+
+ list_del_rcu(&e->list);
+ call_rcu(&e->e_rcu, __gen_kill_estimator);
}
}
+EXPORT_SYMBOL(gen_kill_estimator);
/**
- * gen_replace_estimator - replace rate estimator configruation
+ * gen_replace_estimator - replace rate estimator configuration
* @bstats: basic statistics
* @rate_est: rate estimator statistics
* @stats_lock: statistics lock
*
* Replaces the configuration of a rate estimator by calling
* gen_kill_estimator() and gen_new_estimator().
- *
+ *
* Returns 0 on success or a negative error code.
*/
-int
-gen_replace_estimator(struct gnet_stats_basic *bstats,
- struct gnet_stats_rate_est *rate_est, spinlock_t *stats_lock,
- struct rtattr *opt)
+int gen_replace_estimator(struct gnet_stats_basic_packed *bstats,
+ struct gnet_stats_rate_est *rate_est,
+ spinlock_t *stats_lock, struct nlattr *opt)
{
- gen_kill_estimator(bstats, rate_est);
- return gen_new_estimator(bstats, rate_est, stats_lock, opt);
+ gen_kill_estimator(bstats, rate_est);
+ return gen_new_estimator(bstats, rate_est, stats_lock, opt);
}
-
-
-EXPORT_SYMBOL(gen_kill_estimator);
-EXPORT_SYMBOL(gen_new_estimator);
EXPORT_SYMBOL(gen_replace_estimator);
+
+/**
+ * gen_estimator_active - test if estimator is currently in use
+ * @bstats: basic statistics
+ * @rate_est: rate estimator statistics
+ *
+ * Returns true if estimator is active, and false if not.
+ */
+bool gen_estimator_active(const struct gnet_stats_basic_packed *bstats,
+ const struct gnet_stats_rate_est *rate_est)
+{
+ ASSERT_RTNL();
+
+ return gen_find_node(bstats, rate_est) != NULL;
+}
+EXPORT_SYMBOL(gen_estimator_active);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff