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-rw-r--r--include/linux/percpu.h20
-rw-r--r--init/main.c1
-rw-r--r--mm/percpu.c85
3 files changed, 64 insertions, 42 deletions
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index d3a38d68710..b8b9084527b 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -45,6 +45,16 @@
#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(64 << 10)
/*
+ * Percpu allocator can serve percpu allocations before slab is
+ * initialized which allows slab to depend on the percpu allocator.
+ * The following two parameters decide how much resource to
+ * preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or
+ * larger than PERCPU_DYNAMIC_EARLY_SIZE.
+ */
+#define PERCPU_DYNAMIC_EARLY_SLOTS 128
+#define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10)
+
+/*
* PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
* back on the first chunk for dynamic percpu allocation if arch is
* manually allocating and mapping it for faster access (as a part of
@@ -104,16 +114,11 @@ extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
int nr_units);
extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
-extern struct pcpu_alloc_info * __init pcpu_build_alloc_info(
- size_t reserved_size, ssize_t dyn_size,
- size_t atom_size,
- pcpu_fc_cpu_distance_fn_t cpu_distance_fn);
-
extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
void *base_addr);
#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
-extern int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size,
+extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
size_t atom_size,
pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
pcpu_fc_alloc_fn_t alloc_fn,
@@ -140,6 +145,7 @@ extern bool is_kernel_percpu_address(unsigned long addr);
#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
extern void __init setup_per_cpu_areas(void);
#endif
+extern void __init percpu_init_late(void);
#else /* CONFIG_SMP */
@@ -153,6 +159,8 @@ static inline bool is_kernel_percpu_address(unsigned long addr)
static inline void __init setup_per_cpu_areas(void) { }
+static inline void __init percpu_init_late(void) { }
+
static inline void *pcpu_lpage_remapped(void *kaddr)
{
return NULL;
diff --git a/init/main.c b/init/main.c
index a42fdf4aeba..4ddb53f04f2 100644
--- a/init/main.c
+++ b/init/main.c
@@ -532,6 +532,7 @@ static void __init mm_init(void)
page_cgroup_init_flatmem();
mem_init();
kmem_cache_init();
+ percpu_init_late();
pgtable_cache_init();
vmalloc_init();
}
diff --git a/mm/percpu.c b/mm/percpu.c
index 6470e771023..e61dc2cc587 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -282,6 +282,9 @@ static void __maybe_unused pcpu_next_pop(struct pcpu_chunk *chunk,
*/
static void *pcpu_mem_alloc(size_t size)
{
+ if (WARN_ON_ONCE(!slab_is_available()))
+ return NULL;
+
if (size <= PAGE_SIZE)
return kzalloc(size, GFP_KERNEL);
else {
@@ -392,13 +395,6 @@ static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc)
old_size = chunk->map_alloc * sizeof(chunk->map[0]);
memcpy(new, chunk->map, old_size);
- /*
- * map_alloc < PCPU_DFL_MAP_ALLOC indicates that the chunk is
- * one of the first chunks and still using static map.
- */
- if (chunk->map_alloc >= PCPU_DFL_MAP_ALLOC)
- old = chunk->map;
-
chunk->map_alloc = new_alloc;
chunk->map = new;
new = NULL;
@@ -604,7 +600,7 @@ static struct pcpu_chunk *pcpu_alloc_chunk(void)
{
struct pcpu_chunk *chunk;
- chunk = kzalloc(pcpu_chunk_struct_size, GFP_KERNEL);
+ chunk = pcpu_mem_alloc(pcpu_chunk_struct_size);
if (!chunk)
return NULL;
@@ -1013,20 +1009,6 @@ phys_addr_t per_cpu_ptr_to_phys(void *addr)
return page_to_phys(pcpu_addr_to_page(addr));
}
-static inline size_t pcpu_calc_fc_sizes(size_t static_size,
- size_t reserved_size,
- ssize_t *dyn_sizep)
-{
- size_t size_sum;
-
- size_sum = PFN_ALIGN(static_size + reserved_size +
- (*dyn_sizep >= 0 ? *dyn_sizep : 0));
- if (*dyn_sizep != 0)
- *dyn_sizep = size_sum - static_size - reserved_size;
-
- return size_sum;
-}
-
/**
* pcpu_alloc_alloc_info - allocate percpu allocation info
* @nr_groups: the number of groups
@@ -1085,7 +1067,7 @@ void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai)
/**
* pcpu_build_alloc_info - build alloc_info considering distances between CPUs
* @reserved_size: the size of reserved percpu area in bytes
- * @dyn_size: free size for dynamic allocation in bytes, -1 for auto
+ * @dyn_size: minimum free size for dynamic allocation in bytes
* @atom_size: allocation atom size
* @cpu_distance_fn: callback to determine distance between cpus, optional
*
@@ -1103,8 +1085,8 @@ void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai)
* On success, pointer to the new allocation_info is returned. On
* failure, ERR_PTR value is returned.
*/
-struct pcpu_alloc_info * __init pcpu_build_alloc_info(
- size_t reserved_size, ssize_t dyn_size,
+static struct pcpu_alloc_info * __init pcpu_build_alloc_info(
+ size_t reserved_size, size_t dyn_size,
size_t atom_size,
pcpu_fc_cpu_distance_fn_t cpu_distance_fn)
{
@@ -1123,13 +1105,17 @@ struct pcpu_alloc_info * __init pcpu_build_alloc_info(
memset(group_map, 0, sizeof(group_map));
memset(group_cnt, 0, sizeof(group_cnt));
+ /* calculate size_sum and ensure dyn_size is enough for early alloc */
+ size_sum = PFN_ALIGN(static_size + reserved_size +
+ max_t(size_t, dyn_size, PERCPU_DYNAMIC_EARLY_SIZE));
+ dyn_size = size_sum - static_size - reserved_size;
+
/*
* Determine min_unit_size, alloc_size and max_upa such that
* alloc_size is multiple of atom_size and is the smallest
* which can accomodate 4k aligned segments which are equal to
* or larger than min_unit_size.
*/
- size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, &dyn_size);
min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE);
alloc_size = roundup(min_unit_size, atom_size);
@@ -1350,7 +1336,8 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
void *base_addr)
{
static char cpus_buf[4096] __initdata;
- static int smap[2], dmap[2];
+ static int smap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata;
+ static int dmap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata;
size_t dyn_size = ai->dyn_size;
size_t size_sum = ai->static_size + ai->reserved_size + dyn_size;
struct pcpu_chunk *schunk, *dchunk = NULL;
@@ -1373,14 +1360,13 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
} while (0)
/* sanity checks */
- BUILD_BUG_ON(ARRAY_SIZE(smap) >= PCPU_DFL_MAP_ALLOC ||
- ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC);
PCPU_SETUP_BUG_ON(ai->nr_groups <= 0);
PCPU_SETUP_BUG_ON(!ai->static_size);
PCPU_SETUP_BUG_ON(!base_addr);
PCPU_SETUP_BUG_ON(ai->unit_size < size_sum);
PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK);
PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE);
+ PCPU_SETUP_BUG_ON(ai->dyn_size < PERCPU_DYNAMIC_EARLY_SIZE);
PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0);
/* process group information and build config tables accordingly */
@@ -1532,7 +1518,7 @@ early_param("percpu_alloc", percpu_alloc_setup);
/**
* pcpu_embed_first_chunk - embed the first percpu chunk into bootmem
* @reserved_size: the size of reserved percpu area in bytes
- * @dyn_size: free size for dynamic allocation in bytes, -1 for auto
+ * @dyn_size: minimum free size for dynamic allocation in bytes
* @atom_size: allocation atom size
* @cpu_distance_fn: callback to determine distance between cpus, optional
* @alloc_fn: function to allocate percpu page
@@ -1553,10 +1539,7 @@ early_param("percpu_alloc", percpu_alloc_setup);
* vmalloc space is not orders of magnitude larger than distances
* between node memory addresses (ie. 32bit NUMA machines).
*
- * When @dyn_size is positive, dynamic area might be larger than
- * specified to fill page alignment. When @dyn_size is auto,
- * @dyn_size is just big enough to fill page alignment after static
- * and reserved areas.
+ * @dyn_size specifies the minimum dynamic area size.
*
* If the needed size is smaller than the minimum or specified unit
* size, the leftover is returned using @free_fn.
@@ -1564,7 +1547,7 @@ early_param("percpu_alloc", percpu_alloc_setup);
* RETURNS:
* 0 on success, -errno on failure.
*/
-int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size,
+int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
size_t atom_size,
pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
pcpu_fc_alloc_fn_t alloc_fn,
@@ -1695,7 +1678,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size,
snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10);
- ai = pcpu_build_alloc_info(reserved_size, -1, PAGE_SIZE, NULL);
+ ai = pcpu_build_alloc_info(reserved_size, 0, PAGE_SIZE, NULL);
if (IS_ERR(ai))
return PTR_ERR(ai);
BUG_ON(ai->nr_groups != 1);
@@ -1821,3 +1804,33 @@ void __init setup_per_cpu_areas(void)
__per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
}
#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
+
+/*
+ * First and reserved chunks are initialized with temporary allocation
+ * map in initdata so that they can be used before slab is online.
+ * This function is called after slab is brought up and replaces those
+ * with properly allocated maps.
+ */
+void __init percpu_init_late(void)
+{
+ struct pcpu_chunk *target_chunks[] =
+ { pcpu_first_chunk, pcpu_reserved_chunk, NULL };
+ struct pcpu_chunk *chunk;
+ unsigned long flags;
+ int i;
+
+ for (i = 0; (chunk = target_chunks[i]); i++) {
+ int *map;
+ const size_t size = PERCPU_DYNAMIC_EARLY_SLOTS * sizeof(map[0]);
+
+ BUILD_BUG_ON(size > PAGE_SIZE);
+
+ map = pcpu_mem_alloc(size);
+ BUG_ON(!map);
+
+ spin_lock_irqsave(&pcpu_lock, flags);
+ memcpy(map, chunk->map, size);
+ chunk->map = map;
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+ }
+}