From 1c7df2c24029d6721745b99fd4137935db03e257 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Wed, 9 Mar 2022 09:13:20 +0100
Subject: [PATCH] Revert "Multipage allocation"

This reverts commit 6cd37713781a3092f8166b2178fae35cbfec1e28.
---
 doc/bird.sgml       |  7 -------
 lib/resource.c      |  2 ++
 lib/slab.c          |  2 +-
 sysdep/unix/alloc.c | 23 -----------------------
 sysdep/unix/main.c  | 32 +-------------------------------
 5 files changed, 4 insertions(+), 62 deletions(-)

diff --git a/doc/bird.sgml b/doc/bird.sgml
index ddad4d98..39dadaf2 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -145,13 +145,6 @@ BIRD executable by configuring out routing protocols you don't use, and
 <p>You can pass several command-line options to bird:
 
 <descrip>
-	<tag><label id="argv-block">-B <m/exp/</tag>
-	allocate memory using 2^<cf/exp/ byte sized blocks;
-	if you're expecting high memory load, raise this to
-        reduce number of allocated memory pages. For a million routes
-	in one table, the recommended setting is 18.
-	Default is your system page size, typically 12 for 4096 bytes.
-
 	<tag><label id="argv-config">-c <m/config name/</tag>
 	use given configuration file instead of <it/prefix/<file>/etc/bird.conf</file>.
 
diff --git a/lib/resource.c b/lib/resource.c
index e80b315b..0ad886d9 100644
--- a/lib/resource.c
+++ b/lib/resource.c
@@ -61,6 +61,7 @@ pool root_pool;
 
 void *alloc_sys_page(void);
 void free_sys_page(void *);
+void resource_sys_init(void);
 
 static int indent;
 
@@ -282,6 +283,7 @@ rlookup(unsigned long a)
 void
 resource_init(void)
 {
+  resource_sys_init();
   root_pool.r.class = &pool_class;
   root_pool.name = "Root";
   init_list(&root_pool.inside);
diff --git a/lib/slab.c b/lib/slab.c
index 6348e29b..2fc88ee0 100644
--- a/lib/slab.c
+++ b/lib/slab.c
@@ -178,7 +178,7 @@ struct sl_alignment {			/* Magic structure for testing of alignment */
   int x[0];
 };
 
-#define SL_GET_HEAD(x)	((struct sl_head *) PAGE_HEAD(x))
+#define SL_GET_HEAD(x)	((struct sl_head *) (((uintptr_t) (x)) & ~(page_size-1)))
 
 /**
  * sl_new - create a new Slab
diff --git a/sysdep/unix/alloc.c b/sysdep/unix/alloc.c
index 4c9d5eb5..f6296afe 100644
--- a/sysdep/unix/alloc.c
+++ b/sysdep/unix/alloc.c
@@ -17,7 +17,6 @@
 #endif
 
 long page_size = 0;
-_Bool alloc_multipage = 0;
 
 #ifdef HAVE_MMAP
 static _Bool use_fake = 0;
@@ -46,31 +45,9 @@ alloc_sys_page(void)
 #ifdef HAVE_MMAP
   if (!use_fake)
   {
-    if (alloc_multipage)
-    {
-      void *big = mmap(NULL, page_size * 2, PROT_WRITE | PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-      if (big == MAP_FAILED)
-	bug("mmap(%lu) failed: %m", page_size);
-
-      uintptr_t offset = ((uintptr_t) big) % page_size;
-      if (offset)
-      {
-	void *ret = big + page_size - offset;
-	munmap(big, page_size - offset);
-	munmap(ret + page_size, offset);
-	return ret;
-      }
-      else
-      {
-	munmap(big + page_size, page_size);
-	return big;
-      }
-    }
-
     void *ret = mmap(NULL, page_size, PROT_WRITE | PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
     if (ret == MAP_FAILED)
       bug("mmap(%lu) failed: %m", page_size);
-
     return ret;
   }
   else
diff --git a/sysdep/unix/main.c b/sysdep/unix/main.c
index 7e8ea0dc..cdf0a310 100644
--- a/sysdep/unix/main.c
+++ b/sysdep/unix/main.c
@@ -682,7 +682,7 @@ signal_init(void)
  *	Parsing of command-line arguments
  */
 
-static char *opt_list = "B:c:dD:ps:P:u:g:flRh";
+static char *opt_list = "bc:dD:ps:P:u:g:flRh";
 int parse_and_exit;
 char *bird_name;
 static char *use_user;
@@ -703,7 +703,6 @@ display_help(void)
   fprintf(stderr,
     "\n"
     "Options: \n"
-    "  -B <block-size>	    Use 2^this number as memory allocation block size (default: 12)\n"
     "  -c <config-file>     Use given configuration file instead of\n"
     "                       "  PATH_CONFIG_FILE "\n"
     "  -d                   Enable debug messages and run bird in foreground\n"
@@ -790,15 +789,12 @@ get_gid(const char *s)
   return gr->gr_gid;
 }
 
-extern _Bool alloc_multipage;
-
 static void
 parse_args(int argc, char **argv)
 {
   int config_changed = 0;
   int socket_changed = 0;
   int c;
-  int bp;
 
   bird_name = get_bird_name(argv[0], "bird");
   if (argc == 2)
@@ -811,29 +807,6 @@ parse_args(int argc, char **argv)
   while ((c = getopt(argc, argv, opt_list)) >= 0)
     switch (c)
       {
-      case 'B':
-	bp = atoi(optarg);
-	if (bp < 1)
-	{
-	  fprintf(stderr, "Strange block size power %d\n\n", bp);
-	  display_usage();
-	  exit(1);
-	}
-
-	if ((1 << bp) < page_size)
-	{
-	  fprintf(stderr, "Requested block size %ld is lesser than page size %ld\n\n", (1L<<bp), page_size);
-	  display_usage();
-	  exit(1);
-	}
-
-	if ((1L << bp) > page_size)
-	{
-	  alloc_multipage = 1;
-	  page_size = (1L << bp);
-	}
-
-	break;
       case 'c':
 	config_name = optarg;
 	config_changed = 1;
@@ -888,8 +861,6 @@ parse_args(int argc, char **argv)
    }
 }
 
-void resource_sys_init(void);
-
 /*
  *	Hic Est main()
  */
@@ -902,7 +873,6 @@ main(int argc, char **argv)
     dmalloc_debug(0x2f03d00);
 #endif
 
-  resource_sys_init();
   parse_args(argc, argv);
   log_switch(1, NULL, NULL);