net: Optimize ipfwd and wrbuffer by buffer pool

To allow dynamic allocation of these structs, performance keeps the same
as the previous implementation.

Signed-off-by: Zhe Weng <wengzhe@xiaomi.com>

net/ipforward/Kconfig

@@ -40,3 +40,21 @@ config NET_IPFORWARD_NSTRUCT
 		WARNING: DO NOT set this setting to a value greater than or equal to
 		CONFIG_IOB_NBUFFERS, otherwise it may consume all the IOB and let
 		netdev fail to work.
+
+config NET_IPFORWARD_ALLOC_STRUCT
+	int "Dynamic forwarding structures allocation"
+	default 0
+	---help---
+		When set to 0 all dynamic allocations are disabled
+
+		When set to 1 a new forwarding structure will be allocated every
+		time, and it will be free'd when no longer needed.
+
+		Setting this to 2 or more will allocate the forwarding structures
+		in batches (with batch size equal to this config). When a I/O buffer
+		chain head is no longer needed, it will be returned to the free
+		forwarding structures pool, and it will never be deallocated!
+
+		Note: maximum number of allocated forwarding structures is limited
+		to CONFIG_IOB_NBUFFERS - CONFIG_IOB_THROTTLE to avoid consuming all
+		the IOBs.

net/ipforward/ipfwd_alloc.c

@@ -37,6 +37,7 @@
 #include <nuttx/net/icmpv6.h>
 
 #include "ipforward/ipforward.h"
+#include "utils/utils.h"
 
 #ifdef CONFIG_NET_IPFORWARD
 
@@ -66,13 +67,12 @@
  * Private Data
  ****************************************************************************/
 
-/* This is an array of pre-allocating forwarding structures */
+/* This is the state of the global forwarding structures */
 
-static struct forward_s g_fwdpool[CONFIG_NET_IPFORWARD_NSTRUCT];
-
-/* This is a list of free forwarding structures */
-
-static FAR struct forward_s *g_fwdfree;
+NET_BUFPOOL_DECLARE(g_fwdpool, sizeof(struct forward_s),
+                    CONFIG_NET_IPFORWARD_NSTRUCT,
+                    CONFIG_NET_IPFORWARD_ALLOC_STRUCT,
+                    CONFIG_IOB_NBUFFERS - CONFIG_IOB_THROTTLE);
 
 /****************************************************************************
  * Public Functions
@@ -91,25 +91,13 @@ static FAR struct forward_s *g_fwdfree;
 
 void ipfwd_initialize(void)
 {
-  FAR struct forward_s *fwd;
-  int i;
-
   /* The IOB size must be such that the maximum L2 and L3 headers fit into
    * the contiguous memory of the first IOB in the IOB chain.
    */
 
   DEBUGASSERT(MAX_HDRLEN <= CONFIG_IOB_BUFSIZE);
 
-  /* Add all pre-allocated forwarding structures to the free list */
-
-  g_fwdfree = NULL;
-
-  for (i = 0; i < CONFIG_NET_IPFORWARD_NSTRUCT; i++)
-    {
-      fwd          = &g_fwdpool[i];
-      fwd->f_flink = g_fwdfree;
-      g_fwdfree    = fwd;
-    }
+  NET_BUFPOOL_INIT(g_fwdpool);
 }
 
 /****************************************************************************
@@ -127,16 +115,7 @@ void ipfwd_initialize(void)
 
 FAR struct forward_s *ipfwd_alloc(void)
 {
-  FAR struct forward_s *fwd;
-
-  fwd = g_fwdfree;
-  if (fwd != NULL)
-    {
-      g_fwdfree = fwd->f_flink;
-      memset (fwd, 0, sizeof(struct forward_s));
-    }
-
-  return fwd;
+  return NET_BUFPOOL_TRYALLOC(g_fwdpool);
 }
 
 /****************************************************************************
@@ -153,8 +132,7 @@ FAR struct forward_s *ipfwd_alloc(void)
 
 void ipfwd_free(FAR struct forward_s *fwd)
 {
-  fwd->f_flink = g_fwdfree;
-  g_fwdfree    = fwd;
+  NET_BUFPOOL_FREE(g_fwdpool, fwd);
 }
 
 #endif /* CONFIG_NET_IPFORWARD */

net/tcp/Kconfig

@@ -259,6 +259,20 @@ config NET_TCP_NWRBCHAINS
 		choice for this value would be the same as the maximum number of
 		TCP connections.
 
+config NET_TCP_ALLOC_WRBCHAINS
+	int "Dynamic I/O buffer chain heads allocation"
+	default 0
+	---help---
+		When set to 0 all dynamic allocations are disabled
+
+		When set to 1 a new I/O buffer chain head will be allocated every
+		time, and it will be free'd when no longer needed.
+
+		Setting this to 2 or more will allocate the I/O buffer chain heads
+		in batches (with batch size equal to this config). When a I/O buffer
+		chain head is no longer needed, it will be returned to the free
+		I/O buffer chain heads pool, and it will never be deallocated!
+
 config NET_TCP_WRBUFFER_DEBUG
 	bool "Force write buffer debug"
 	default n

net/tcp/tcp_wrbuffer.c

@@ -48,34 +48,15 @@
 
 #if defined(CONFIG_NET_TCP) && defined(CONFIG_NET_TCP_WRITE_BUFFERS)
 
-/****************************************************************************
- * Private Types
- ****************************************************************************/
-
-/* Package all globals used by this logic into a structure */
-
-struct wrbuffer_s
-{
-  /* The semaphore to protect the buffers */
-
-  sem_t sem;
-
-  /* This is the list of available write buffers */
-
-  sq_queue_t freebuffers;
-
-  /* These are the pre-allocated write buffers */
-
-  struct tcp_wrbuffer_s buffers[CONFIG_NET_TCP_NWRBCHAINS];
-};
-
 /****************************************************************************
  * Private Data
  ****************************************************************************/
 
 /* This is the state of the global write buffer resource */
 
-static struct wrbuffer_s g_wrbuffer;
+NET_BUFPOOL_DECLARE(g_wrbuffer, sizeof(struct tcp_wrbuffer_s),
+                    CONFIG_NET_TCP_NWRBCHAINS,
+                    CONFIG_NET_TCP_ALLOC_WRBCHAINS, 0);
 
 /****************************************************************************
  * Public Functions
@@ -94,16 +75,7 @@ static struct wrbuffer_s g_wrbuffer;
 
 void tcp_wrbuffer_initialize(void)
 {
-  int i;
-
-  sq_init(&g_wrbuffer.freebuffers);
-
-  nxsem_init(&g_wrbuffer.sem, 0, CONFIG_NET_TCP_NWRBCHAINS);
-
-  for (i = 0; i < CONFIG_NET_TCP_NWRBCHAINS; i++)
-    {
-      sq_addfirst(&g_wrbuffer.buffers[i].wb_node, &g_wrbuffer.freebuffers);
-    }
+  NET_BUFPOOL_INIT(g_wrbuffer);
 }
 
 /****************************************************************************
@@ -127,7 +99,6 @@ void tcp_wrbuffer_initialize(void)
 FAR struct tcp_wrbuffer_s *tcp_wrbuffer_timedalloc(unsigned int timeout)
 {
   FAR struct tcp_wrbuffer_s *wrb;
-  int ret;
 
   /* We need to allocate two things:  (1) A write buffer structure and (2)
    * at least one I/O buffer to start the chain.
@@ -137,20 +108,12 @@ FAR struct tcp_wrbuffer_s *tcp_wrbuffer_timedalloc(unsigned int timeout)
    * buffer
    */
 
-  ret = net_sem_timedwait_uninterruptible(&g_wrbuffer.sem, timeout);
-  if (ret != OK)
+  wrb = NET_BUFPOOL_TIMEDALLOC(g_wrbuffer, timeout);
+  if (wrb == NULL)
     {
       return NULL;
     }
 
-  /* Now, we are guaranteed to have a write buffer structure reserved
-   * for us in the free list.
-   */
-
-  wrb = (FAR struct tcp_wrbuffer_s *)sq_remfirst(&g_wrbuffer.freebuffers);
-  DEBUGASSERT(wrb);
-  memset(wrb, 0, sizeof(struct tcp_wrbuffer_s));
-
   /* Now get the first I/O buffer for the write buffer structure */
 
   wrb->wb_iob = net_iobtimedalloc(true, timeout);
@@ -247,8 +210,7 @@ void tcp_wrbuffer_release(FAR struct tcp_wrbuffer_s *wrb)
 
   /* Then free the write buffer structure */
 
-  sq_addlast(&wrb->wb_node, &g_wrbuffer.freebuffers);
-  nxsem_post(&g_wrbuffer.sem);
+  NET_BUFPOOL_FREE(g_wrbuffer, wrb);
 }
 
 /****************************************************************************
@@ -304,16 +266,7 @@ uint32_t tcp_wrbuffer_inqueue_size(FAR struct tcp_conn_s *conn)
 
 int tcp_wrbuffer_test(void)
 {
-  int val = 0;
-  int ret;
-
-  ret = nxsem_get_value(&g_wrbuffer.sem, &val);
-  if (ret >= 0)
-    {
-      ret = val > 0 ? OK : -ENOSPC;
-    }
-
-  return ret;
+  return NET_BUFPOOL_TEST(g_wrbuffer);
 }
 
 #endif /* CONFIG_NET_TCP && CONFIG_NET_TCP_WRITE_BUFFERS */

net/udp/Kconfig

@@ -103,6 +103,20 @@ config NET_UDP_NWRBCHAINS
 		choice for this value would be the same as the maximum number of
 		UDP connections.
 
+config NET_UDP_ALLOC_WRBCHAINS
+	int "Dynamic I/O buffer chain heads allocation"
+	default 0
+	---help---
+		When set to 0 all dynamic allocations are disabled.
+
+		When set to 1 a new I/O buffer chain head will be allocated every
+		time, and it will be free'd when no longer needed.
+
+		Setting this to 2 or more will allocate the I/O buffer chain heads
+		in batches (with batch size equal to this config). When a I/O buffer
+		chain head is no longer needed, it will be returned to the free
+		I/O buffer chain heads pool, and it will never be deallocated!
+
 config NET_UDP_WRBUFFER_DEBUG
 	bool "Force write buffer debug"
 	default n