mm: Add total_unmovable_pages global variable

Vmalloc will exit if the amount it needs to allocate is
greater than totalram_pages. Vmalloc cannot allocate
from the movable zone, so pages in the movable zone should
not be counted.

This change adds a new global variable: total_unmovable_pages.
It is calculated in init.c, based on totalram_pages minus
the pages in the movable zone. Vmalloc now looks at this new
global instead of totalram_pages.

total_unmovable_pages can be modified during memory_hotplug.
If the zone you are offlining/onlining is unmovable, then
you modify it similar to totalram_pages.  If the zone is
movable, then no change is needed.

Change-Id: Ie55c41051e9ad4b921eb04ecbb4798a8bd2344d6
Signed-off-by: Jack Cheung <jackc@codeaurora.org>
(cherry picked from commit 59f9f1c9ae463a3d4499cd9353619f8b1993371b)

Conflicts:

	arch/arm/mm/init.c
	mm/memory_hotplug.c
	mm/page_alloc.c
	mm/vmalloc.c

arch/arm/mm/init.c

@@ -624,6 +624,9 @@ void __init mem_init(void)
 	extern u32 dtcm_end;
 	extern u32 itcm_end;
 #endif
+#ifdef CONFIG_FIX_MOVABLE_ZONE
+	struct zone *zone;
+#endif
 
 	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
 
@@ -662,6 +665,14 @@ void __init mem_init(void)
 		} while (page < end);
 	}
 
+#ifdef CONFIG_FIX_MOVABLE_ZONE
+	for_each_zone(zone) {
+		if (zone_idx(zone) == ZONE_MOVABLE)
+			total_unmovable_pages = totalram_pages -
+							zone->spanned_pages;
+	}
+#endif
+
 	/*
 	 * Since our memory may not be contiguous, calculate the
 	 * real number of pages we have in this system
@@ -759,6 +770,7 @@ void __init mem_init(void)
 
 void free_initmem(void)
 {
+	unsigned long reclaimed_initmem;
 #ifdef CONFIG_HAVE_TCM
 	extern char __tcm_start, __tcm_end;
 
@@ -769,10 +781,15 @@ void free_initmem(void)
 #endif
 
 	poison_init_mem(__init_begin, __init_end - __init_begin);
-	if (!machine_is_integrator() && !machine_is_cintegrator())
-		totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
+	if (!machine_is_integrator() && !machine_is_cintegrator()) {
+		reclaimed_initmem = free_area(__phys_to_pfn(__pa(__init_begin)),
 					    __phys_to_pfn(__pa(__init_end)),
 					    "init");
+		totalram_pages += reclaimed_initmem;
+#ifdef CONFIG_FIX_MOVABLE_ZONE
+		total_unmovable_pages += reclaimed_initmem;
+#endif
+	}
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD
@@ -781,11 +798,17 @@ static int keep_initrd;
 
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
+	unsigned long reclaimed_initrd_mem;
+
 	if (!keep_initrd) {
 		poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
-		totalram_pages += free_area(__phys_to_pfn(__pa(start)),
+		reclaimed_initrd_mem = free_area(__phys_to_pfn(__pa(start)),
 						 __phys_to_pfn(__pa(end)),
 						 "initrd");
+		totalram_pages += reclaimed_initrd_mem;
+#ifdef CONFIG_FIX_MOVABLE_ZONE
+		total_unmovable_pages += reclaimed_initrd_mem;
+#endif
 	}
 }
 

include/linux/mm.h

@@ -31,6 +31,9 @@ extern unsigned long max_mapnr;
 
 extern unsigned long num_physpages;
 extern unsigned long totalram_pages;
+#ifdef CONFIG_FIX_MOVABLE_ZONE
+extern unsigned long total_unmovable_pages;
+#endif
 extern void * high_memory;
 extern int page_cluster;
 

mm/memory_hotplug.c

@@ -410,6 +410,11 @@ void __online_page_set_limits(struct page *page)
 {
 	unsigned long pfn = page_to_pfn(page);
 
+	totalram_pages++;
+#ifdef CONFIG_FIX_MOVABLE_ZONE
+	if (zone_idx(page_zone(page)) != ZONE_MOVABLE)
+		total_unmovable_pages++;
+#endif
 	if (pfn >= num_physpages)
 		num_physpages = pfn + 1;
 }
@@ -962,6 +967,10 @@ repeat:
 	zone->zone_pgdat->node_present_pages -= offlined_pages;
 	totalram_pages -= offlined_pages;
 
+#ifdef CONFIG_FIX_MOVABLE_ZONE
+	if (zone_idx(zone) != ZONE_MOVABLE)
+		total_unmovable_pages -= offlined_pages;
+#endif
 	init_per_zone_wmark_min();
 
 	if (!node_present_pages(node)) {

mm/page_alloc.c

@@ -105,6 +105,9 @@ unsigned long totalreserve_pages __read_mostly;
  */
 unsigned long dirty_balance_reserve __read_mostly;
 
+#ifdef CONFIG_FIX_MOVABLE_ZONE
+unsigned long total_unmovable_pages __read_mostly;
+#endif
 int percpu_pagelist_fraction;
 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
 
@@ -176,6 +179,9 @@ int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
 };
 
 EXPORT_SYMBOL(totalram_pages);
+#ifdef CONFIG_FIX_MOVABLE_ZONE
+EXPORT_SYMBOL(total_unmovable_pages);
+#endif
 
 static char * const zone_names[MAX_NR_ZONES] = {
 #ifdef CONFIG_ZONE_DMA

mm/vmalloc.c

@@ -1647,9 +1647,14 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
 	struct vm_struct *area;
 	void *addr;
 	unsigned long real_size = size;
+#ifdef CONFIG_FIX_MOVABLE_ZONE
+	unsigned long total_pages = total_unmovable_pages;
+#else
+	unsigned long total_pages = totalram_pages;
+#endif
 
 	size = PAGE_ALIGN(size);
-	if (!size || (size >> PAGE_SHIFT) > totalram_pages)
+	if (!size || (size >> PAGE_SHIFT) > total_pages)
 		goto fail;
 
 	area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNLIST,