From 01a2a10715551ccbad760cec641786aa079c373a Mon Sep 17 00:00:00 2001
From: Dave Barach <dave@barachs.net>
Date: Thu, 11 Jun 2020 08:57:52 -0400
Subject: [PATCH] ip: allocate ip4 mtrie pages in htlb memory

No change in default behavior. To use htlb pages for the ip4 mtrie,
use the "ip" command-line option "mtrie-hugetlb".

Type: improvement

Signed-off-by: Dave Barach <dave@barachs.net>
Change-Id: I5497e426a47200edff2c7e15563ed6a42af12e7f
---
 src/vnet/ip/ip4.h         |  3 +++
 src/vnet/ip/ip4_forward.c |  3 +++
 src/vnet/ip/ip4_mtrie.c   | 44 ++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/src/vnet/ip/ip4.h b/src/vnet/ip/ip4.h
index b5bc2e2c33f..f5ed9385232 100644
--- a/src/vnet/ip/ip4.h
+++ b/src/vnet/ip/ip4.h
@@ -167,6 +167,9 @@ typedef struct ip4_main_t
   /** Heapsize for the Mtries */
   uword mtrie_heap_size;
 
+  /** Use hugetlb pages for the Mtries */
+  int mtrie_hugetlb;
+
   /** The memory heap for the mtries */
   void *mtrie_mheap;
 
diff --git a/src/vnet/ip/ip4_forward.c b/src/vnet/ip/ip4_forward.c
index 0fa9da22c93..595a0a1913c 100644
--- a/src/vnet/ip/ip4_forward.c
+++ b/src/vnet/ip/ip4_forward.c
@@ -3097,10 +3097,13 @@ ip4_config (vlib_main_t * vm, unformat_input_t * input)
     {
       if (unformat (input, "heap-size %U", unformat_memory_size, &heapsize))
 	;
+      else if (unformat (input, "mtrie-hugetlb %=", &im->mtrie_hugetlb, 1))
+	;
       else
 	return clib_error_return (0,
 				  "invalid heap-size parameter `%U'",
 				  format_unformat_error, input);
+
     }
 
   im->mtrie_heap_size = heapsize;
diff --git a/src/vnet/ip/ip4_mtrie.c b/src/vnet/ip/ip4_mtrie.c
index 258a0f76bdc..b5d0a890a7c 100644
--- a/src/vnet/ip/ip4_mtrie.c
+++ b/src/vnet/ip/ip4_mtrie.c
@@ -790,6 +790,9 @@ format_ip4_fib_mtrie (u8 * s, va_list * va)
 
 /** Default heap size for the IPv4 mtries */
 #define IP4_FIB_DEFAULT_MTRIE_HEAP_SIZE (32<<20)
+#ifndef MAP_HUGE_SHIFT
+#define MAP_HUGE_SHIFT 26
+#endif
 
 static clib_error_t *
 ip4_mtrie_module_init (vlib_main_t * vm)
@@ -799,9 +802,46 @@ ip4_mtrie_module_init (vlib_main_t * vm)
   clib_error_t *error = NULL;
   uword *old_heap;
 
-  if (0 == im->mtrie_heap_size)
+  if (im->mtrie_heap_size == 0)
     im->mtrie_heap_size = IP4_FIB_DEFAULT_MTRIE_HEAP_SIZE;
-  im->mtrie_mheap = create_mspace (im->mtrie_heap_size, 1 /* locked */ );
+
+again:
+  if (im->mtrie_hugetlb)
+    {
+      void *rv;
+      int mmap_flags, mmap_flags_huge;
+      uword htlb_pagesize = clib_mem_get_default_hugepage_size ();
+      if (htlb_pagesize == 0)
+	{
+	  clib_warning ("WARNING: htlb pagesize == 0");
+	  im->mtrie_hugetlb = 0;
+	  goto again;
+	}
+      /* Round the allocation request to an even number of huge pages */
+      im->mtrie_heap_size = (im->mtrie_heap_size + (htlb_pagesize - 1)) &
+	~(htlb_pagesize - 1);
+      mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS;
+      mmap_flags_huge = (mmap_flags | MAP_HUGETLB | MAP_LOCKED |
+			 min_log2 (htlb_pagesize) << MAP_HUGE_SHIFT);
+      rv = mmap (0, im->mtrie_heap_size,
+		 PROT_READ | PROT_WRITE, mmap_flags_huge, -1, 0);
+      if (rv == MAP_FAILED)
+	{
+	  /* Failure when running as root should be logged... */
+	  if (geteuid () == 0)
+	    clib_warning ("ip4 mtrie htlb map failed: not enough pages?");
+	  im->mtrie_hugetlb = 0;
+	  goto again;
+	}
+      if (mlock (rv, im->mtrie_heap_size))
+	clib_warning ("WARNING: couldn't lock mtrie heap at %llx", rv);
+      im->mtrie_mheap = create_mspace_with_base (rv, im->mtrie_heap_size,
+						 1 /* locked */ );
+    }
+  else
+    {
+      im->mtrie_mheap = create_mspace (im->mtrie_heap_size, 1 /* locked */ );
+    }
 
   /* Burn one ply so index 0 is taken */
   old_heap = clib_mem_set_heap (ip4_main.mtrie_mheap);
-- 
2.16.6