From 90759047b3c1858f4832515282307058d6a9fba2 Mon Sep 17 00:00:00 2001
From: Abdulaziz Ghuloum <aghuloum@cs.indiana.edu>
Date: Sat, 17 Nov 2007 13:26:27 -0500
Subject: [PATCH] * The fasl loader has reduced the startup mmap frenzy for
 code   objects from 5242 pages (almost one page per code object) down   to
 785 pages.  Special thanks to Michael Adams for counting the   the number of
 pages that were used and touched at startup; without   his help, I wouldn't
 have optimized it in about 10 minutes of   coding time.

---
 src/Makefile.in   |  2 +-
 src/ikarus-fasl.c | 35 +++++++++++++++++++++++++++++------
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/src/Makefile.in b/src/Makefile.in
index 15f2885..379d9b5 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -484,7 +484,7 @@ bootfileloc.h: Makefile
 
 scheme-script: 
 	echo "#!/bin/sh" > scheme-script
-	echo "$(bindir)/ikarus --r6rs-script \$$@" >> scheme-script
+	echo "exec $(bindir)/ikarus --r6rs-script \$$@" >> scheme-script
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
 # Otherwise a system limit (for SysV at least) may be exceeded.
 .NOEXPORT:
diff --git a/src/ikarus-fasl.c b/src/ikarus-fasl.c
index 3a9563b..1a222ad 100644
--- a/src/ikarus-fasl.c
+++ b/src/ikarus-fasl.c
@@ -45,6 +45,8 @@ typedef struct {
   char* membase;
   char* memp;
   char* memq;
+  ikp code_ap;
+  ikp code_ep;
 #endif
   ikp* marks;
   int marks_size;
@@ -66,6 +68,8 @@ void ik_fasl_load(ikpcb* pcb, char* fasl_file){
   p.marks_size = 0;
   ikp v = ik_fasl_read(pcb, &p);
   while(v){
+    p.code_ap = 0;
+    p.code_ep = 0;
     if(p.marks){
       bzero(p.marks, p.marks_size * sizeof(ikp*));
     }
@@ -153,12 +157,31 @@ void ik_fasl_load(ikpcb* pcb, char* fasl_file){
 }
 #endif
 
-
 static ikp 
-alloc_code(int size, ikpcb* pcb){
-  int required_memory = align_to_next_page(size);
-  ikp mem = ik_mmap_code(required_memory, 0, pcb);
-  return (ikp)mem;
+alloc_code(int size, ikpcb* pcb, fasl_port* p){
+  int asize = align(size);
+  ikp ap = p->code_ap;
+  ikp nap = ap + asize;
+  if(nap <= p->code_ep){
+    p->code_ap = nap;
+    return ap;
+  } else if (asize < pagesize){
+    ikp mem = ik_mmap_code(pagesize, 0, pcb);
+    int bytes_remaining = pagesize - asize;
+    int previous_bytes = 
+      ((unsigned int)p->code_ep) - ((unsigned int)ap);
+    if(bytes_remaining <= previous_bytes){
+      return mem;
+    } else {
+      p->code_ap = mem+asize;
+      p->code_ep = mem+pagesize;
+      return mem;
+    }
+  } else {
+    int asize = align_to_next_page(size);
+    ikp mem = ik_mmap_code(asize, 0, pcb);
+    return mem;
+  }
 }
 
 
@@ -305,7 +328,7 @@ static ikp do_read(ikpcb* pcb, fasl_port* p){
     fasl_read_buf(p, &code_size, sizeof(int));
     fasl_read_buf(p, &freevars, sizeof(ikp));
     ikp annotation = do_read(pcb, p);
-    ikp code = alloc_code(align(code_size+disp_code_data), pcb);
+    ikp code = alloc_code(align(code_size+disp_code_data), pcb, p);
     ref(code, 0) = code_tag;
     ref(code, disp_code_code_size) = fix(code_size);
     ref(code, disp_code_freevars) = freevars;