From 80073d46d9466615fa3815ea33cc30e63ba3c24e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maxime=20Ch=C3=A9ramy?= <maxime81@gmail.com>
Date: Tue, 20 Jan 2015 18:09:19 +0100
Subject: [PATCH] [vmm] bugfix increase_heap: augmente le dernier slab libre si
 possible. ref #173

---
 kernel/memory.c | 28 ++++++++++++++++------------
 kernel/vmm.c    | 15 +++++----------
 2 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/kernel/memory.c b/kernel/memory.c
index 1c32fd59..5b066899 100644
--- a/kernel/memory.c
+++ b/kernel/memory.c
@@ -197,19 +197,23 @@ void memory_setup(size_t ram_size) {
 paddr_t memory_reserve_page_frame()
 {
 	struct physical_page_descr *p = free_frame_pages;
- 
-	// pop it from free page stack
-	free_frame_pages = free_frame_pages->next;
-	if(free_frame_pages != NULL)
-		free_frame_pages->prev = NULL;
- 
-	// put the new reserved on used page stack
-	used_frame_pages->prev = p;
-	p->next = used_frame_pages;
-	used_frame_pages = p;
-	p->prev = NULL;
 
-	return p->addr;
+	if (p != NULL) {
+		// pop it from free page stack
+		free_frame_pages = free_frame_pages->next;
+		if(free_frame_pages != NULL)
+			free_frame_pages->prev = NULL;
+
+		// put the new reserved on used page stack
+		used_frame_pages->prev = p;
+		p->next = used_frame_pages;
+		used_frame_pages = p;
+		p->prev = NULL;
+
+		return p->addr;
+	} else {
+		return 0;
+	}
 }
 
 int memory_free_page_frame(paddr_t addr)
diff --git a/kernel/vmm.c b/kernel/vmm.c
index 323152fb..4a82b580 100644
--- a/kernel/vmm.c
+++ b/kernel/vmm.c
@@ -254,20 +254,15 @@ static int increase_heap(struct virtual_mem *vm, unsigned int nb_pages, int u_s)
 	/* vaddr_t top_last_slab; unused */
 	struct slab *slab = (struct slab *) vm->vmm_top;
 
-	for(i=0 ; i<nb_pages ; i++)
-	{
-		if(memory_get_first_free_page() == NULL)
-			return -1;
-		if(map(memory_reserve_page_frame(), vm->vmm_top, u_s) == -1)
+	for (i = 0; i < nb_pages; i++){
+		paddr_t paddr = memory_reserve_page_frame();
+		if(!paddr || map(paddr, vm->vmm_top, u_s) == -1)
 			return -1;
 		vm->vmm_top += PAGE_SIZE;
 	}
 	
-	/* Il semble que si on calcul cette ligne à cet endroit, et que on a !is_empty(&(vm->free_slabs)), ça plante, alors
-	 * je commente et j'insert directement la ligne dans le if 
-	 * top_last_slab = (vaddr_t) vm->free_slabs.end + vm->free_slabs.end->nb_pages*PAGE_SIZE;*/
-	
-	if(!is_empty(&(vm->free_slabs)) && ((vaddr_t) vm->free_slabs.end + vm->free_slabs.end->nb_pages*PAGE_SIZE) == vm->vmm_top)
+	// S'il y a un free slab et que la fin correspond à la fin du heap:
+	if(!is_empty(&(vm->free_slabs)) && ((vaddr_t) vm->free_slabs.end + vm->free_slabs.end->nb_pages*PAGE_SIZE) == (vaddr_t)slab)
 	{
 	 	// agrandit juste le dernier free slab
 		vm->free_slabs.end->nb_pages += nb_pages;