[PATCHv4] opensm: Reduce heap consumption by unicast routing tables (LFTs)

[Hal Rosenstock <hnrose-Wuw85uim5zDR7s880joybQ@public.gmane.org>]

Heap memory consumption by the unicast and multicast routing tables can be
reduced.

Using valgrind --tool=massif (for heap profiling), there are couple of places that consume most of the heap memory:
->38.75% (11,206,656B) 0x43267E: osm_switch_new (osm_switch.c:134)
->12.89% (3,728,256B) 0x40F8C9: osm_mcast_tbl_init (osm_mcast_tbl.c:96)

osm_switch_new (osm_switch.c:108):
       p_sw->lft = malloc(IB_LID_UCAST_END_HO + 1);

>From ib_types.h
 #define IB_LID_UCAST_END_HO 0xBFFF

The LFT can be allocated after LID assignment, once the number of LIDs
assigned is known.

So it looks like for cluster of 2-4K with an LMC of 0 about 40% (!!!) of the
heap memory can be saved:

 - 39% used by LFTs, each with 48K entries - SM can allocate 4K entries instead.

A similar subsequent change will do this for MFTs.

Signed-off-by: Hal Rosenstock <hal.rosenstock-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
Changes since v3:
Fixed comparisons to lft_size to use max_lid_ho
Modifications to alloc_lft
- Simpler calculation of lft_size in units of LFT block size
- Eliminated unneeded malloc case for LFT when no LFT

Changes since v2:
Fixed alloc_lft handling of an existing lft
Moved alloc_lft into osm_switch_prepare_path_rebuild 

Changes since v1:
Basic approach changed to not do in chunks but rather allocate
LFT once LID assignment is completed

diff --git a/opensm/include/opensm/osm_switch.h b/opensm/include/opensm/osm_switch.h
index 502e5a7..655491d 100644
--- a/opensm/include/opensm/osm_switch.h
+++ b/opensm/include/opensm/osm_switch.h
@@ -102,6 +102,7 @@ typedef struct osm_switch {
 	osm_port_profile_t *p_prof;
 	uint8_t *lft;
 	uint8_t *new_lft;
+	uint16_t lft_size;
 	osm_mcast_tbl_t mcast_tbl;
 	int32_t mft_block_num;
 	uint32_t mft_position;
@@ -405,7 +406,7 @@ uint8_t osm_switch_get_port_least_hops(IN const osm_switch_t * p_sw,
 static inline uint8_t osm_switch_get_port_by_lid(IN const osm_switch_t * p_sw,
 						 IN uint16_t lid_ho)
 {
-	if (lid_ho == 0 || lid_ho > IB_LID_UCAST_END_HO)
+	if (lid_ho == 0 || lid_ho > p_sw->max_lid_ho)
 		return OSM_NO_PATH;
 	return p_sw->lft[lid_ho];
 }
@@ -711,7 +712,7 @@ osm_switch_set_lft_block(IN osm_switch_t * p_sw, IN const uint8_t * p_block,
 		(uint16_t) (block_num * IB_SMP_DATA_SIZE);
 	CL_ASSERT(p_sw);
 
-	if (lid_start + IB_SMP_DATA_SIZE > IB_LID_UCAST_END_HO)
+	if (lid_start + IB_SMP_DATA_SIZE > p_sw->lft_size)
 		return IB_INVALID_PARAMETER;
 
 	memcpy(&p_sw->lft[lid_start], p_block, IB_SMP_DATA_SIZE);
diff --git a/opensm/opensm/osm_state_mgr.c b/opensm/opensm/osm_state_mgr.c
index 185c700..c40c9d3 100644
--- a/opensm/opensm/osm_state_mgr.c
+++ b/opensm/opensm/osm_state_mgr.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2004-2008 Voltaire, Inc. All rights reserved.
- * Copyright (c) 2002-2008 Mellanox Technologies LTD. All rights reserved.
+ * Copyright (c) 2002-2009 Mellanox Technologies LTD. All rights reserved.
  * Copyright (c) 1996-2003 Intel Corporation. All rights reserved.
  * Copyright (c) 2009 HNR Consulting. All rights reserved.
  *
@@ -1011,9 +1011,9 @@ static void cleanup_switch(cl_map_item_t * item, void *log)
 	if (!sw->new_lft)
 		return;
 
-	if (memcmp(sw->lft, sw->new_lft, IB_LID_UCAST_END_HO + 1))
+	if (memcmp(sw->lft, sw->new_lft, sw->lft_size))
 		osm_log(log, OSM_LOG_ERROR, "ERR 331D: "
-			"LFT of switch 0x%016" PRIx64 " is not up to date.\n",
+			"LFT of switch 0x%016" PRIx64 " is not up to date\n",
 			cl_ntoh64(sw->p_node->node_info.node_guid));
 	else {
 		free(sw->new_lft);
diff --git a/opensm/opensm/osm_switch.c b/opensm/opensm/osm_switch.c
index ad1018f..00aad5a 100644
--- a/opensm/opensm/osm_switch.c
+++ b/opensm/opensm/osm_switch.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2004-2008 Voltaire, Inc. All rights reserved.
- * Copyright (c) 2002-2008 Mellanox Technologies LTD. All rights reserved.
+ * Copyright (c) 2002-2009 Mellanox Technologies LTD. All rights reserved.
  * Copyright (c) 1996-2003 Intel Corporation. All rights reserved.
  * Copyright (c) 2009 HNR Consulting. All rights reserved.
  *
@@ -130,12 +130,6 @@ osm_switch_t *osm_switch_new(IN osm_node_t * p_node,
 	p_sw->num_ports = num_ports;
 	p_sw->need_update = 2;
 
-	p_sw->lft = malloc(IB_LID_UCAST_END_HO + 1);
-	if (!p_sw->lft)
-		goto err;
-
-	memset(p_sw->lft, OSM_NO_PATH, IB_LID_UCAST_END_HO + 1);
-
 	p_sw->p_prof = malloc(sizeof(*p_sw->p_prof) * num_ports);
 	if (!p_sw->p_prof)
 		goto err;
@@ -166,7 +160,7 @@ boolean_t osm_switch_get_lft_block(IN const osm_switch_t * p_sw,
 	CL_ASSERT(p_sw);
 	CL_ASSERT(p_block);
 
-	if (base_lid_ho > p_sw->max_lid_ho)
+	if (base_lid_ho >= p_sw->lft_size)
 		return FALSE;
 
 	CL_ASSERT(base_lid_ho + IB_SMP_DATA_SIZE <= IB_LID_UCAST_END_HO);
@@ -498,21 +492,46 @@ void osm_switch_clear_hops(IN osm_switch_t * p_sw)
 
 /**********************************************************************
  **********************************************************************/
+static int alloc_lft(IN osm_switch_t * p_sw, uint16_t lids)
+{
+	uint16_t lft_size;
+	uint8_t *new_lft;
+
+	lft_size = lids;
+	/* Ensure LFT is in units of LFT block size */
+	lft_size = (lids + IB_SMP_DATA_SIZE - 1) / IB_SMP_DATA_SIZE * IB_SMP_DATA_SIZE;
+
+	if (lft_size > p_sw->lft_size) {
+		new_lft = realloc(p_sw->lft, lft_size);
+		if (!new_lft)
+			return -1;
+		memset(new_lft + p_sw->lft_size, OSM_NO_PATH,
+		       lft_size - p_sw->lft_size);
+		p_sw->lft = new_lft;
+		p_sw->lft_size = lft_size;
+	}
+	return 0;
+}
+
+/**********************************************************************
+ **********************************************************************/
 int osm_switch_prepare_path_rebuild(IN osm_switch_t * p_sw, IN uint16_t max_lids)
 {
 	uint8_t **hops;
 	unsigned i;
 
+	if (alloc_lft(p_sw, max_lids))
+		return -1;
+
 	for (i = 0; i < p_sw->num_ports; i++)
 		osm_port_prof_construct(&p_sw->p_prof[i]);
 
 	osm_switch_clear_hops(p_sw);
 
-	if (!p_sw->new_lft &&
-	    !(p_sw->new_lft = malloc(IB_LID_UCAST_END_HO + 1)))
-		return IB_INSUFFICIENT_MEMORY;
+	if (!(p_sw->new_lft = realloc(p_sw->new_lft, p_sw->lft_size)))
+		return -1;
 
-	memset(p_sw->new_lft, OSM_NO_PATH, IB_LID_UCAST_END_HO + 1);
+	memset(p_sw->new_lft, OSM_NO_PATH, p_sw->lft_size);
 
 	if (!p_sw->hops) {
 		hops = malloc((max_lids + 1) * sizeof(hops[0]));
diff --git a/opensm/opensm/osm_ucast_cache.c b/opensm/opensm/osm_ucast_cache.c
index 6d3c53e..31a5333 100644
--- a/opensm/opensm/osm_ucast_cache.c
+++ b/opensm/opensm/osm_ucast_cache.c
@@ -1079,10 +1079,10 @@ int osm_ucast_cache_process(osm_ucast_mgr_t * p_mgr)
 			/* no new routing was recently calculated for this
 			   switch, but the LFT needs to be updated anyway */
 			p_sw->new_lft = p_sw->lft;
-			p_sw->lft = malloc(IB_LID_UCAST_END_HO + 1);
+			p_sw->lft = malloc(p_sw->lft_size);
 			if (!p_sw->lft)
 				return IB_INSUFFICIENT_MEMORY;
-			memset(p_sw->lft, OSM_NO_PATH, IB_LID_UCAST_END_HO + 1);
+			memset(p_sw->lft, OSM_NO_PATH, p_sw->lft_size);
 		}
 
 	}
diff --git a/opensm/opensm/osm_ucast_file.c b/opensm/opensm/osm_ucast_file.c
index 5b73ca5..7c1b5ba 100644
--- a/opensm/opensm/osm_ucast_file.c
+++ b/opensm/opensm/osm_ucast_file.c
@@ -193,8 +193,7 @@ static int do_ucast_file_load(void *context)
 					cl_ntoh64(sw_guid));
 				continue;
 			}
-			memset(p_sw->new_lft, OSM_NO_PATH,
-			       IB_LID_UCAST_END_HO + 1);
+			memset(p_sw->new_lft, OSM_NO_PATH, p_sw->lft_size);
 		} else if (p_sw && !strncmp(p, "0x", 2)) {
 			p += 2;
 			lid = (uint16_t) strtoul(p, &q, 16);
diff --git a/opensm/opensm/osm_ucast_ftree.c b/opensm/opensm/osm_ucast_ftree.c
index 1defd95..885c834 100644
--- a/opensm/opensm/osm_ucast_ftree.c
+++ b/opensm/opensm/osm_ucast_ftree.c
@@ -566,7 +566,7 @@ static ftree_sw_t *sw_create(IN ftree_fabric_t * p_ftree,
 		return NULL;
 
 	/* initialize lft buffer */
-	memset(p_osm_sw->new_lft, OSM_NO_PATH, IB_LID_UCAST_END_HO + 1);
+	memset(p_osm_sw->new_lft, OSM_NO_PATH, p_osm_sw->lft_size);
 	p_sw->hops = malloc((p_osm_sw->max_lid_ho + 1) * sizeof(*(p_sw->hops)));
 	if (p_sw->hops == NULL)
 		return NULL;
diff --git a/opensm/opensm/osm_ucast_lash.c b/opensm/opensm/osm_ucast_lash.c
index 8b0a190..8015226 100644
--- a/opensm/opensm/osm_ucast_lash.c
+++ b/opensm/opensm/osm_ucast_lash.c
@@ -994,7 +994,7 @@ static void populate_fwd_tbls(lash_t * p_lash)
 
 	p_next_sw = (osm_switch_t *) cl_qmap_head(&p_subn->sw_guid_tbl);
 
-	/* Go through each swtich individually */
+	/* Go through each switch individually */
 	while (p_next_sw != (osm_switch_t *) cl_qmap_end(&p_subn->sw_guid_tbl)) {
 		uint64_t current_guid;
 		switch_t *sw;
@@ -1005,7 +1005,7 @@ static void populate_fwd_tbls(lash_t * p_lash)
 		current_guid = p_sw->p_node->node_info.port_guid;
 		sw = p_sw->priv;
 
-		memset(p_sw->new_lft, OSM_NO_PATH, IB_LID_UCAST_END_HO + 1);
+		memset(p_sw->new_lft, OSM_NO_PATH, p_sw->lft_size);
 
 		for (lid = 1; lid <= max_lid_ho; lid++) {
 			port = cl_ptr_vector_get(&p_subn->port_lid_tbl, lid);
diff --git a/opensm/opensm/osm_ucast_mgr.c b/opensm/opensm/osm_ucast_mgr.c
index be37df9..d0e85b1 100644
--- a/opensm/opensm/osm_ucast_mgr.c
+++ b/opensm/opensm/osm_ucast_mgr.c
@@ -372,7 +372,7 @@ static void ucast_mgr_process_tbl(IN cl_map_item_t * p_map_item,
 		cl_ntoh64(osm_node_get_node_guid(p_sw->p_node)));
 
 	/* Initialize LIDs in buffer to invalid port number. */
-	memset(p_sw->new_lft, OSM_NO_PATH, IB_LID_UCAST_END_HO + 1);
+	memset(p_sw->new_lft, OSM_NO_PATH, p_sw->max_lid_ho + 1);
 
 	if (p_mgr->p_subn->opt.lmc)
 		alloc_ports_priv(p_mgr);
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