Add a MCA parameter to fix the size of the maximum buffer that can be allocated by TCP (tcp_frag_size).

This commit was SVN r3390.

src/mca/ptl/tcp/src/ptl_tcp.h

@@ -36,13 +36,14 @@ struct mca_ptl_tcp_component_t {
     size_t tcp_max_ptl_modules;            /**< maximum number of ptls - available kernel ifs */
     int tcp_listen_sd;                     /**< listen socket for incoming connection requests */
     unsigned short tcp_listen_port;        /**< listen port */
-    char* tcp_if_include;                  /**< comma seperated list of interface to include */
-    char* tcp_if_exclude;                  /**< comma seperated list of interface to exclude */
-    int   tcp_free_list_num;               /**< initial size of free lists */
-    int   tcp_free_list_max;               /**< maximum size of free lists */
-    int   tcp_free_list_inc;               /**< number of elements to alloc when growing free lists */
-    int   tcp_sndbuf;                      /**< socket sndbuf size */
-    int   tcp_rcvbuf;                      /**< socket rcvbuf size */
+    char*  tcp_if_include;                 /**< comma seperated list of interface to include */
+    char*  tcp_if_exclude;                 /**< comma seperated list of interface to exclude */
+    int    tcp_free_list_num;              /**< initial size of free lists */
+    int    tcp_free_list_max;              /**< maximum size of free lists */
+    int    tcp_free_list_inc;              /**< number of elements to alloc when growing free lists */
+    int    tcp_sndbuf;                     /**< socket sndbuf size */
+    int    tcp_rcvbuf;                     /**< socket rcvbuf size */
+    size_t tcp_frag_size;                  /**< buffer limit for the TCP PTL */
     ompi_free_list_t tcp_send_frags;       /**< free list of tcp send fragments */
     ompi_free_list_t tcp_recv_frags;       /**< free list of tcp recv fragments */
     ompi_hash_table_t tcp_procs;           /**< hash table of tcp proc structures */

src/mca/ptl/tcp/src/ptl_tcp_component.c

@@ -182,7 +182,14 @@ int mca_ptl_tcp_component_open(void)
         mca_ptl_tcp_param_register_int("min_frag_size", 64*1024);
     mca_ptl_tcp_module.super.ptl_max_frag_size =
         mca_ptl_tcp_param_register_int("max_frag_size", -1);
-
+    /* the tcp allocator will never allocate buffers with more than this size */
+    mca_ptl_tcp_component.tcp_frag_size =
+        mca_ptl_tcp_param_register_int("frag_size", 16*1024);
+    /* adapt the first fragment size to fit with the allowed fragment size */
+    if( (mca_ptl_tcp_component.tcp_frag_size != 0) &&
+        (mca_ptl_tcp_module.super.ptl_first_frag_size > mca_ptl_tcp_component.tcp_frag_size) ) {
+        mca_ptl_tcp_module.super.ptl_first_frag_size = mca_ptl_tcp_component.tcp_frag_size;
+    }
     return OMPI_SUCCESS;
 }
 

src/mca/ptl/tcp/src/ptl_tcp_sendfrag.c

@@ -48,9 +48,13 @@ static void mca_ptl_tcp_send_frag_destruct(mca_ptl_tcp_send_frag_t* frag)
 {
 }
 
+extern mca_ptl_tcp_component_t mca_ptl_tcp_component;
+
 void* mca_ptl_tcp_memalloc( unsigned int* length )
 {
-  return malloc( *length );
+   if( (*length) > mca_ptl_tcp_component.tcp_frag_size )
+      *length = mca_ptl_tcp_component.tcp_frag_size;
+   return malloc( *length );
 }
 
 /*