Improvements in Netlink connections allocation.

This commit is contained in:
Fotis Panagiotopoulos 2023-02-13 16:57:17 +02:00 committed by Xiang Xiao
parent 74bb921a19
commit cf15d6b63a
2 changed files with 71 additions and 13 deletions

View File

@ -22,11 +22,46 @@ config NET_NETLINK
if NET_NETLINK
config NETLINK_CONNS
int "Number of Netlink connections"
config NETLINK_PREALLOC_CONNS
int "Preallocated Netlink connections"
default 4
---help---
Maximum number of Netlink connections (all tasks).
Number of Netlink connections (all tasks).
This number of connections will be pre-allocated during system boot.
If dynamic connections allocation is enabled, more connections may
be allocated at a later time, as the system needs them. Else this
will be the maximum number of connections available to the system
at all times.
Set to 0 to disable (and rely only on dynamic allocations).
config NETLINK_ALLOC_CONNS
int "Dynamic Netlink connections allocation"
default 0
---help---
Dynamic memory allocations for Netlink.
When set to 0 all dynamic allocations are disabled.
When set to 1 a new connection will be allocated every time,
and it will be free'd when no longer needed.
Setting this to 2 or more will allocate the connections in
batches (with batch size equal to this config). When a
connection is no longer needed, it will be returned to the
free connections pool, and it will never be deallocated!
config NETLINK_MAX_CONNS
int "Maximum number of Netlink connections"
default 0
depends on NETLINK_ALLOC_CONNS > 0
---help---
If dynamic connections allocation is selected (NETLINK_ALLOC_CONNS > 0)
this will limit the number of connections that can be allocated.
This is useful in case the system is under very heavy load (or
under attack), ensuring that the heap will not be exhausted.
menu "Netlink Protocols"

View File

@ -51,8 +51,9 @@
/* The array containing all NetLink connections. */
#ifndef CONFIG_NET_ALLOC_CONNS
static struct netlink_conn_s g_netlink_connections[CONFIG_NETLINK_CONNS];
#if CONFIG_NETLINK_PREALLOC_CONNS > 0
static struct netlink_conn_s
g_netlink_connections[CONFIG_NETLINK_PREALLOC_CONNS];
#endif
/* A list of all free NetLink connections */
@ -106,10 +107,10 @@ static void netlink_response_available(FAR void *arg)
void netlink_initialize(void)
{
#ifndef CONFIG_NET_ALLOC_CONNS
#if CONFIG_NETLINK_PREALLOC_CONNS > 0
int i;
for (i = 0; i < CONFIG_NETLINK_CONNS; i++)
for (i = 0; i < CONFIG_NETLINK_PREALLOC_CONNS; i++)
{
/* Mark the connection closed and move it to the free list */
@ -131,20 +132,29 @@ void netlink_initialize(void)
FAR struct netlink_conn_s *netlink_alloc(void)
{
FAR struct netlink_conn_s *conn;
#ifdef CONFIG_NET_ALLOC_CONNS
#if CONFIG_NETLINK_ALLOC_CONNS > 0
int i;
#endif
/* The free list is protected by a mutex. */
nxmutex_lock(&g_free_lock);
#ifdef CONFIG_NET_ALLOC_CONNS
#if CONFIG_NETLINK_ALLOC_CONNS > 0
if (dq_peek(&g_free_netlink_connections) == NULL)
{
conn = kmm_zalloc(sizeof(*conn) * CONFIG_NETLINK_CONNS);
#if CONFIG_NETLINK_MAX_CONNS > 0
if (dq_count(&g_active_netlink_connections) +
CONFIG_NETLINK_ALLOC_CONNS >= CONFIG_NETLINK_MAX_CONNS)
{
nxmutex_unlock(&g_free_lock);
return NULL;
}
#endif
conn = kmm_zalloc(sizeof(*conn) * CONFIG_NETLINK_ALLOC_CONNS);
if (conn != NULL)
{
for (i = 0; i < CONFIG_NETLINK_CONNS; i++)
for (i = 0; i < CONFIG_NETLINK_ALLOC_CONNS; i++)
{
dq_addlast(&conn[i].sconn.node, &g_free_netlink_connections);
}
@ -199,9 +209,22 @@ void netlink_free(FAR struct netlink_conn_s *conn)
memset(conn, 0, sizeof(*conn));
/* Free the connection */
/* If this is a preallocated or a batch allocated connection store it in
* the free connections list. Else free it.
*/
#if CONFIG_NETLINK_ALLOC_CONNS == 1
if (conn < g_netlink_connections || conn >= (g_netlink_connections +
CONFIG_NETLINK_PREALLOC_CONNS))
{
kmm_free(conn);
}
else
#endif
{
dq_addlast(&conn->sconn.node, &g_free_netlink_connections);
}
nxmutex_unlock(&g_free_lock);
}