[PATCH 2/3] mm/memblock: Allocate boot time data structures from mirrored memory

From: Tony Luck
Date: Mon May 04 2015 - 16:58:12 EST


Try to allocate all boot time kernel data structures from mirrored
memory. If we run out of mirrored memory print warnings, but fall
back to using non-mirrored memory to make sure that we still boot.

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
include/linux/memblock.h | 8 ++++++
mm/memblock.c | 71 ++++++++++++++++++++++++++++++++++++++++++------
mm/nobootmem.c | 10 ++++++-
3 files changed, 79 insertions(+), 10 deletions(-)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 1d448879caae..20bf3dfab564 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -22,6 +22,7 @@

/* Definition of memblock flags. */
#define MEMBLOCK_HOTPLUG 0x1 /* hotpluggable region */
+#define MEMBLOCK_MIRROR 0x2 /* mirrored region */

struct memblock_region {
phys_addr_t base;
@@ -75,6 +76,8 @@ int memblock_reserve(phys_addr_t base, phys_addr_t size);
void memblock_trim_memory(phys_addr_t align);
int memblock_mark_hotplug(phys_addr_t base, phys_addr_t size);
int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size);
+int memblock_mark_mirror(phys_addr_t base, phys_addr_t size);
+u32 memblock_has_mirror(void);

/* Low level functions */
int memblock_add_range(struct memblock_type *type,
@@ -155,6 +158,11 @@ static inline bool movable_node_is_enabled(void)
}
#endif

+static inline bool memblock_is_mirror(struct memblock_region *m)
+{
+ return m->flags & MEMBLOCK_MIRROR;
+}
+
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn,
unsigned long *end_pfn);
diff --git a/mm/memblock.c b/mm/memblock.c
index ac3c94fff97c..7a0769555474 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -54,10 +54,16 @@ int memblock_debug __initdata_memblock;
#ifdef CONFIG_MOVABLE_NODE
bool movable_node_enabled __initdata_memblock = false;
#endif
+static bool memblock_have_mirror __initdata_memblock = false;
static int memblock_can_resize __initdata_memblock;
static int memblock_memory_in_slab __initdata_memblock = 0;
static int memblock_reserved_in_slab __initdata_memblock = 0;

+u32 __init_memblock memblock_has_mirror(void)
+{
+ return memblock_have_mirror ? MEMBLOCK_MIRROR : 0;
+}
+
/* inline so we don't get a warning when pr_debug is compiled out */
static __init_memblock const char *
memblock_type_name(struct memblock_type *type)
@@ -257,8 +263,19 @@ phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
phys_addr_t end, phys_addr_t size,
phys_addr_t align)
{
- return memblock_find_in_range_node(size, align, start, end,
+ phys_addr_t ret;
+ u32 flag = memblock_has_mirror();
+
+ ret = memblock_find_in_range_node(size, align, start, end,
+ NUMA_NO_NODE, flag);
+
+ if (!ret && flag) {
+ pr_warn("Could not allocate %lld bytes of mirrored memory\n", size);
+ ret = memblock_find_in_range_node(size, align, start, end,
NUMA_NO_NODE, 0);
+ }
+
+ return ret;
}

static void __init_memblock memblock_remove_region(struct memblock_type *type, unsigned long r)
@@ -784,6 +801,21 @@ int __init_memblock memblock_clear_hotplug(phys_addr_t base, phys_addr_t size)
}

/**
+ * memblock_mark_mirror - Mark mirrored memory with flag MEMBLOCK_MIRROR.
+ * @base: the base phys addr of the region
+ * @size: the size of the region
+ *
+ * Return 0 on succees, -errno on failure.
+ */
+int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
+{
+ memblock_have_mirror = true;
+
+ return memblock_setclr_flag(base, size, 1, MEMBLOCK_MIRROR);
+}
+
+
+/**
* __next__mem_range - next function for for_each_free_mem_range() etc.
* @idx: pointer to u64 loop variable
* @nid: node selector, %NUMA_NO_NODE for all nodes
@@ -837,6 +869,10 @@ void __init_memblock __next_mem_range(u64 *idx, int nid, u32 flags,
if (movable_node_is_enabled() && memblock_is_hotpluggable(m))
continue;

+ /* if we want mirror memory skip non-mirror memory regions */
+ if ((flags & MEMBLOCK_MIRROR) && !memblock_is_mirror(m))
+ continue;
+
if (!type_b) {
if (out_start)
*out_start = m_start;
@@ -942,6 +978,10 @@ void __init_memblock __next_mem_range_rev(u64 *idx, int nid, u32 flags,
if (movable_node_is_enabled() && memblock_is_hotpluggable(m))
continue;

+ /* if we want mirror memory skip non-mirror memory regions */
+ if ((flags & MEMBLOCK_MIRROR) && !memblock_is_mirror(m))
+ continue;
+
if (!type_b) {
if (out_start)
*out_start = m_start;
@@ -1092,7 +1132,17 @@ static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size,

phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid)
{
- return memblock_alloc_base_nid(size, align, MEMBLOCK_ALLOC_ACCESSIBLE, nid, 0);
+ u32 flag = memblock_has_mirror();
+ phys_addr_t ret;
+
+again:
+ ret = memblock_alloc_base_nid(size, align, MEMBLOCK_ALLOC_ACCESSIBLE, nid, flag);
+
+ if (!ret && flag) {
+ flag = 0;
+ goto again;
+ }
+ return ret;
}

phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
@@ -1161,6 +1211,7 @@ static void * __init memblock_virt_alloc_internal(
{
phys_addr_t alloc;
void *ptr;
+ u32 flag = memblock_has_mirror();

if (WARN_ONCE(nid == MAX_NUMNODES, "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
nid = NUMA_NO_NODE;
@@ -1181,13 +1232,13 @@ static void * __init memblock_virt_alloc_internal(

again:
alloc = memblock_find_in_range_node(size, align, min_addr, max_addr,
- nid, 0);
+ nid, flag);
if (alloc)
goto done;

if (nid != NUMA_NO_NODE) {
alloc = memblock_find_in_range_node(size, align, min_addr,
- max_addr, NUMA_NO_NODE, 0);
+ max_addr, NUMA_NO_NODE, flag);
if (alloc)
goto done;
}
@@ -1195,10 +1246,15 @@ again:
if (min_addr) {
min_addr = 0;
goto again;
- } else {
- goto error;
}

+ if (flag) {
+ flag = 0;
+ pr_warn("Could not allocate %lld bytes of mirrored memory\n", size);
+ goto again;
+ }
+
+ return NULL;
done:
memblock_reserve(alloc, size);
ptr = phys_to_virt(alloc);
@@ -1213,9 +1269,6 @@ done:
kmemleak_alloc(ptr, size, 0, 0);

return ptr;
-
-error:
- return NULL;
}

/**
diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index a4903046bcba..35423c935a46 100644
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -37,11 +37,19 @@ static void * __init __alloc_memory_core_early(int nid, u64 size, u64 align,
{
void *ptr;
u64 addr;
+ u32 flag = memblock_has_mirror();

if (limit > memblock.current_limit)
limit = memblock.current_limit;

- addr = memblock_find_in_range_node(size, align, goal, limit, nid, 0);
+again:
+ addr = memblock_find_in_range_node(size, align, goal, limit, nid, flag);
+
+ if (flag && !addr) {
+ flag = 0;
+ pr_warn("Could not allocate %lld bytes of mirrored memory\n", size);
+ goto again;
+ }
if (!addr)
return NULL;

--
2.1.4

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