author: Florian Westphal <fw@strlen.de> 2021-07-27 00:29:19 +0200
committer: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2021-09-03 10:22:45 +0200
commit: 7aa03980b21fdc7355e20274a68a69a0b2a45c08
parent: e0f824abe0f412f769fb5468b36c2471430bd885
Commit Summary:
Diffstat:
1 file changed, 21 insertions, 46 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 69079a382d3a..6ba9f4b8d145 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -68,22 +68,17 @@ EXPORT_SYMBOL_GPL(nf_conntrack_hash);
struct conntrack_gc_work {
struct delayed_work dwork;
- u32 last_bucket;
+ u32 next_bucket;
bool exiting;
bool early_drop;
- long next_gc_run;
};
static __read_mostly struct kmem_cache *nf_conntrack_cachep;
static DEFINE_SPINLOCK(nf_conntrack_locks_all_lock);
static __read_mostly bool nf_conntrack_locks_all;
-/* every gc cycle scans at most 1/GC_MAX_BUCKETS_DIV part of table */
-#define GC_MAX_BUCKETS_DIV 128u
-/* upper bound of full table scan */
-#define GC_MAX_SCAN_JIFFIES (16u * HZ)
-/* desired ratio of entries found to be expired */
-#define GC_EVICT_RATIO 50u
+#define GC_SCAN_INTERVAL (120u * HZ)
+#define GC_SCAN_MAX_DURATION msecs_to_jiffies(10)
static struct conntrack_gc_work conntrack_gc_work;
@@ -1359,17 +1354,13 @@ static bool gc_worker_can_early_drop(const struct nf_conn *ct)
static void gc_worker(struct work_struct *work)
{
- unsigned int min_interval = max(HZ / GC_MAX_BUCKETS_DIV, 1u);
- unsigned int i, goal, buckets = 0, expired_count = 0;
- unsigned int nf_conntrack_max95 = 0;
+ unsigned long end_time = jiffies + GC_SCAN_MAX_DURATION;
+ unsigned int i, hashsz, nf_conntrack_max95 = 0;
+ unsigned long next_run = GC_SCAN_INTERVAL;
struct conntrack_gc_work *gc_work;
- unsigned int ratio, scanned = 0;
- unsigned long next_run;
-
gc_work = container_of(work, struct conntrack_gc_work, dwork.work);
- goal = nf_conntrack_htable_size / GC_MAX_BUCKETS_DIV;
- i = gc_work->last_bucket;
+ i = gc_work->next_bucket;
if (gc_work->early_drop)
nf_conntrack_max95 = nf_conntrack_max / 100u * 95u;
@@ -1377,15 +1368,15 @@ static void gc_worker(struct work_struct *work)
struct nf_conntrack_tuple_hash *h;
struct hlist_nulls_head *ct_hash;
struct hlist_nulls_node *n;
- unsigned int hashsz;
struct nf_conn *tmp;
- i++;
rcu_read_lock();
nf_conntrack_get_ht(&ct_hash, &hashsz);
- if (i >= hashsz)
- i = 0;
+ if (i >= hashsz) {
+ rcu_read_unlock();
+ break;
+ }
hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[i], hnnode) {
struct nf_conntrack_net *cnet;
@@ -1393,7 +1384,6 @@ static void gc_worker(struct work_struct *work)
tmp = nf_ct_tuplehash_to_ctrack(h);
- scanned++;
if (test_bit(IPS_OFFLOAD_BIT, &tmp->status)) {
nf_ct_offload_timeout(tmp);
continue;
@@ -1401,7 +1391,6 @@ static void gc_worker(struct work_struct *work)
if (nf_ct_is_expired(tmp)) {
nf_ct_gc_expired(tmp);
- expired_count++;
continue;
}
@@ -1434,7 +1423,14 @@ static void gc_worker(struct work_struct *work)
*/
rcu_read_unlock();
cond_resched();
- } while (++buckets < goal);
+ i++;
+
+ if (time_after(jiffies, end_time) && i < hashsz) {
+ gc_work->next_bucket = i;
+ next_run = 0;
+ break;
+ }
+ } while (i < hashsz);
if (gc_work->exiting)
return;
@@ -1445,40 +1441,17 @@ static void gc_worker(struct work_struct *work)
*
* This worker is only here to reap expired entries when system went
* idle after a busy period.
- *
- * The heuristics below are supposed to balance conflicting goals:
- *
- * 1. Minimize time until we notice a stale entry
- * 2. Maximize scan intervals to not waste cycles
- *
- * Normally, expire ratio will be close to 0.
- *
- * As soon as a sizeable fraction of the entries have expired
- * increase scan frequency.
*/
- ratio = scanned ? expired_count * 100 / scanned : 0;
- if (ratio > GC_EVICT_RATIO) {
- gc_work->next_gc_run = min_interval;
- } else {
- unsigned int max = GC_MAX_SCAN_JIFFIES / GC_MAX_BUCKETS_DIV;
-
- BUILD_BUG_ON((GC_MAX_SCAN_JIFFIES / GC_MAX_BUCKETS_DIV) == 0);
-
- gc_work->next_gc_run += min_interval;
- if (gc_work->next_gc_run > max)
- gc_work->next_gc_run = max;
+ if (next_run) {
+ gc_work->early_drop = false;
+ gc_work->next_bucket = 0;
}
-
- next_run = gc_work->next_gc_run;
- gc_work->last_bucket = i;
- gc_work->early_drop = false;
queue_delayed_work(system_power_efficient_wq, &gc_work->dwork, next_run);
}
static void conntrack_gc_work_init(struct conntrack_gc_work *gc_work)
{
INIT_DEFERRABLE_WORK(&gc_work->dwork, gc_worker);
- gc_work->next_gc_run = HZ;
gc_work->exiting = false;
}