bgpd: split soft reconfigure table task into several jobs to not block vtysh

BGP configuration changes that imply recomputing the BGP route table
(e.g. modifying route-maps, setting bgp graceful-shutdown) might be a
long time process depending on the size of the BGP table and the
route-map numbers and complexity. For example, setups with full
Internet routes take something like one minute to reprocess all the
prefixes when graceful-shutdown is configured. During this time, a
"show bgp commands" request on vtysh results in blocking the shell until
the soft reconfigure table task is over.

This patch splits bgp_soft_reconfig_table task into thread jobs of 25K
prefixes.

Some tests on a full Internet route setup show that after reconfiguring
route-maps or graceful-shutdown, vtysh is not stucked anymore. We are
now able to request commands like "show bgp summary" after 1 or 2
seconds instead of 30 to 60s.

Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/bgpd/bgp_table.h b/bgpd/bgp_table.h
index 68b460149..fb906aa1f 100644
--- a/bgpd/bgp_table.h
+++ b/bgpd/bgp_table.h
@@ -42,6 +42,13 @@ struct bgp_table {
 
 	int lock;
 
+	/* soft_reconfig_table in progress */
+	bool soft_reconfig_init;
+	struct thread *soft_reconfig_thread;
+
+	/* list of peers on which soft_reconfig_table has to run */
+	struct list *soft_reconfig_peers;
+
 	struct route_table *route_table;
 	uint64_t version;
 };
@@ -96,7 +103,7 @@ struct bgp_node {
 
 	mpls_label_t local_label;
 
-	uint8_t flags;
+	uint16_t flags;
 #define BGP_NODE_PROCESS_SCHEDULED	(1 << 0)
 #define BGP_NODE_USER_CLEAR             (1 << 1)
 #define BGP_NODE_LABEL_CHANGED          (1 << 2)
@@ -105,6 +112,7 @@ struct bgp_node {
 #define BGP_NODE_FIB_INSTALL_PENDING    (1 << 5)
 #define BGP_NODE_FIB_INSTALLED          (1 << 6)
 #define BGP_NODE_LABEL_REQUESTED        (1 << 7)
+#define BGP_NODE_SOFT_RECONFIG (1 << 8)
 
 	struct bgp_addpath_node_data tx_addpath;