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authorPablo Neira Ayuso <pablo@netfilter.org>2012-05-08 21:39:49 +0400
committerPablo Neira Ayuso <pablo@netfilter.org>2012-05-08 21:39:53 +0400
commit1c003b1580e20ff9f500846677303a695b1837cc (patch)
treed00c951b6e4c88edd403b4d8ead96a57b9bfc808 /include/net/ip_vs.h
parentcdcc5e905d59026fbf2e7f74f9cc834203b6207b (diff)
downloadlinux-1c003b1580e20ff9f500846677303a695b1837cc.tar.xz
ipvs: wakeup master thread
High rate of sync messages in master can lead to overflowing the socket buffer and dropping the messages. Fixed sleep of 1 second without wakeup events is not suitable for loaded masters, Use delayed_work to schedule sending for queued messages and limit the delay to IPVS_SYNC_SEND_DELAY (20ms). This will reduce the rate of wakeups but to avoid sending long bursts we wakeup the master thread after IPVS_SYNC_WAKEUP_RATE (8) messages. Add hard limit for the queued messages before sending by using "sync_qlen_max" sysctl var. It defaults to 1/32 of the memory pages but actually represents number of messages. It will protect us from allocating large parts of memory when the sending rate is lower than the queuing rate. As suggested by Pablo, add new sysctl var "sync_sock_size" to configure the SNDBUF (master) or RCVBUF (slave) socket limit. Default value is 0 (preserve system defaults). Change the master thread to detect and block on SNDBUF overflow, so that we do not drop messages when the socket limit is low but the sync_qlen_max limit is not reached. On ENOBUFS or other errors just drop the messages. Change master thread to enter TASK_INTERRUPTIBLE state early, so that we do not miss wakeups due to messages or kthread_should_stop event. Thanks to Pablo Neira Ayuso for his valuable feedback! Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
Diffstat (limited to 'include/net/ip_vs.h')
-rw-r--r--include/net/ip_vs.h29
1 files changed, 29 insertions, 0 deletions
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 93b81aa73429..30e43c8c0283 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -869,6 +869,8 @@ struct netns_ipvs {
#endif
int sysctl_snat_reroute;
int sysctl_sync_ver;
+ int sysctl_sync_qlen_max;
+ int sysctl_sync_sock_size;
int sysctl_cache_bypass;
int sysctl_expire_nodest_conn;
int sysctl_expire_quiescent_template;
@@ -889,6 +891,9 @@ struct netns_ipvs {
struct timer_list est_timer; /* Estimation timer */
/* ip_vs_sync */
struct list_head sync_queue;
+ int sync_queue_len;
+ unsigned int sync_queue_delay;
+ struct delayed_work master_wakeup_work;
spinlock_t sync_lock;
struct ip_vs_sync_buff *sync_buff;
spinlock_t sync_buff_lock;
@@ -911,6 +916,10 @@ struct netns_ipvs {
#define DEFAULT_SYNC_THRESHOLD 3
#define DEFAULT_SYNC_PERIOD 50
#define DEFAULT_SYNC_VER 1
+#define IPVS_SYNC_WAKEUP_RATE 8
+#define IPVS_SYNC_QLEN_MAX (IPVS_SYNC_WAKEUP_RATE * 4)
+#define IPVS_SYNC_SEND_DELAY (HZ / 50)
+#define IPVS_SYNC_CHECK_PERIOD HZ
#ifdef CONFIG_SYSCTL
@@ -929,6 +938,16 @@ static inline int sysctl_sync_ver(struct netns_ipvs *ipvs)
return ipvs->sysctl_sync_ver;
}
+static inline int sysctl_sync_qlen_max(struct netns_ipvs *ipvs)
+{
+ return ipvs->sysctl_sync_qlen_max;
+}
+
+static inline int sysctl_sync_sock_size(struct netns_ipvs *ipvs)
+{
+ return ipvs->sysctl_sync_sock_size;
+}
+
#else
static inline int sysctl_sync_threshold(struct netns_ipvs *ipvs)
@@ -946,6 +965,16 @@ static inline int sysctl_sync_ver(struct netns_ipvs *ipvs)
return DEFAULT_SYNC_VER;
}
+static inline int sysctl_sync_qlen_max(struct netns_ipvs *ipvs)
+{
+ return IPVS_SYNC_QLEN_MAX;
+}
+
+static inline int sysctl_sync_sock_size(struct netns_ipvs *ipvs)
+{
+ return 0;
+}
+
#endif
/*