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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

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* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: update comments to reflect that percpu allocations are always zero-filled
  percpu: Optimize __get_cpu_var()
  x86, percpu: Optimize this_cpu_ptr
  percpu: clear memory allocated with the km allocator
  percpu: fix build breakage on s390 and cleanup build configuration tests
  percpu: use percpu allocator on UP too
  percpu: reduce PCPU_MIN_UNIT_SIZE to 32k
  vmalloc: pcpu_get/free_vm_areas() aren't needed on UP

Fixed up trivial conflicts in include/linux/percpu.h
This commit is contained in:
Linus Torvalds 2010-10-22 17:31:36 -07:00
commit 0fc0531e0a
10 changed files with 422 additions and 377 deletions
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14
arch/x86/include/asm/percpu.h
View File

@ -47,6 +47,20 @@
#ifdef CONFIG_SMP
#define __percpu_arg(x) "%%"__stringify(__percpu_seg)":%P" #x
#define __my_cpu_offset percpu_read(this_cpu_off)
/*
* Compared to the generic __my_cpu_offset version, the following
* saves one instruction and avoids clobbering a temp register.
*/
#define __this_cpu_ptr(ptr) \
({ \
unsigned long tcp_ptr__; \
__verify_pcpu_ptr(ptr); \
asm volatile("add " __percpu_arg(1) ", %0" \
: "=r" (tcp_ptr__) \
: "m" (this_cpu_off), "0" (ptr)); \
(typeof(*(ptr)) __kernel __force *)tcp_ptr__; \
})
#else
#define __percpu_arg(x) "%P" #x
#endif

14
include/asm-generic/percpu.h
View File

@ -55,14 +55,18 @@ extern unsigned long __per_cpu_offset[NR_CPUS];
*/
#define per_cpu(var, cpu) \
(*SHIFT_PERCPU_PTR(&(var), per_cpu_offset(cpu)))
#define __get_cpu_var(var) \
(*SHIFT_PERCPU_PTR(&(var), my_cpu_offset))
#define __raw_get_cpu_var(var) \
(*SHIFT_PERCPU_PTR(&(var), __my_cpu_offset))
#define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset)
#ifndef __this_cpu_ptr
#define __this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset)
#endif
#ifdef CONFIG_DEBUG_PREEMPT
#define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset)
#else
#define this_cpu_ptr(ptr) __this_cpu_ptr(ptr)
#endif
#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
#define __raw_get_cpu_var(var) (*__this_cpu_ptr(&(var)))
#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
extern void setup_per_cpu_areas(void);

31
include/linux/percpu.h
View File

@ -48,10 +48,8 @@
preempt_enable(); \
} while (0)
#ifdef CONFIG_SMP
/* minimum unit size, also is the maximum supported allocation size */
#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(64 << 10)
#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
/*
* Percpu allocator can serve percpu allocations before slab is
@ -146,37 +144,20 @@ extern int __init pcpu_page_first_chunk(size_t reserved_size,
* dynamically allocated. Non-atomic access to the current CPU's
* version should probably be combined with get_cpu()/put_cpu().
*/
#ifdef CONFIG_SMP
#define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
#else
#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); VERIFY_PERCPU_PTR((ptr)); })
#endif
extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
extern bool is_kernel_percpu_address(unsigned long addr);
#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
#if !defined(CONFIG_SMP) || !defined(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 */
#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); VERIFY_PERCPU_PTR((ptr)); })
/* can't distinguish from other static vars, always false */
static inline bool is_kernel_percpu_address(unsigned long addr)
{
return false;
}
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;
}
#endif /* CONFIG_SMP */
extern void __percpu *__alloc_percpu(size_t size, size_t align);
extern void free_percpu(void __percpu *__pdata);
extern phys_addr_t per_cpu_ptr_to_phys(void *addr);

2
include/linux/vmalloc.h
View File

@ -117,10 +117,12 @@ extern rwlock_t vmlist_lock;
extern struct vm_struct *vmlist;
extern __init void vm_area_register_early(struct vm_struct *vm, size_t align);
#ifdef CONFIG_SMP
struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
const size_t *sizes, int nr_vms,
size_t align, gfp_t gfp_mask);
void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms);
#endif
#endif /* _LINUX_VMALLOC_H */

8
mm/Kconfig
View File

@ -301,3 +301,11 @@ config NOMMU_INITIAL_TRIM_EXCESS
of 1 says that all excess pages should be trimmed.
See Documentation/nommu-mmap.txt for more information.
#
# UP and nommu archs use km based percpu allocator
#
config NEED_PER_CPU_KM
depends on !SMP
bool
default y

7
mm/Makefile
View File

@ -11,7 +11,7 @@ obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \
maccess.o page_alloc.o page-writeback.o \
readahead.o swap.o truncate.o vmscan.o shmem.o \
prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \
page_isolation.o mm_init.o mmu_context.o \
page_isolation.o mm_init.o mmu_context.o percpu.o \
$(mmu-y)
obj-y += init-mm.o
@ -36,11 +36,6 @@ obj-$(CONFIG_FAILSLAB) += failslab.o
obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
obj-$(CONFIG_FS_XIP) += filemap_xip.o
obj-$(CONFIG_MIGRATION) += migrate.o
ifdef CONFIG_SMP
obj-y += percpu.o
else
obj-y += percpu_up.o
endif
obj-$(CONFIG_QUICKLIST) += quicklist.o
obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o
obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o

8
mm/percpu-km.c
View File

@ -27,7 +27,7 @@
* chunk size is not aligned. percpu-km code will whine about it.
*/
#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
#if defined(CONFIG_SMP) && defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK)
#error "contiguous percpu allocation is incompatible with paged first chunk"
#endif
@ -35,7 +35,11 @@
static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size)
{
/* noop */
unsigned int cpu;
for_each_possible_cpu(cpu)
memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
return 0;
}

683
mm/percpu.c
View File

@ -76,6 +76,7 @@
#define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */
#define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */
#ifdef CONFIG_SMP
/* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */
#ifndef __addr_to_pcpu_ptr
#define __addr_to_pcpu_ptr(addr) \
@ -89,6 +90,11 @@
(unsigned long)pcpu_base_addr - \
(unsigned long)__per_cpu_start)
#endif
#else /* CONFIG_SMP */
/* on UP, it's always identity mapped */
#define __addr_to_pcpu_ptr(addr) (void __percpu *)(addr)
#define __pcpu_ptr_to_addr(ptr) (void __force *)(ptr)
#endif /* CONFIG_SMP */
struct pcpu_chunk {
struct list_head list; /* linked to pcpu_slot lists */
@ -820,8 +826,8 @@ fail_unlock_mutex:
* @size: size of area to allocate in bytes
* @align: alignment of area (max PAGE_SIZE)
*
* Allocate percpu area of @size bytes aligned at @align. Might
* sleep. Might trigger writeouts.
* Allocate zero-filled percpu area of @size bytes aligned at @align.
* Might sleep. Might trigger writeouts.
*
* CONTEXT:
* Does GFP_KERNEL allocation.
@ -840,9 +846,10 @@ EXPORT_SYMBOL_GPL(__alloc_percpu);
* @size: size of area to allocate in bytes
* @align: alignment of area (max PAGE_SIZE)
*
* Allocate percpu area of @size bytes aligned at @align from reserved
* percpu area if arch has set it up; otherwise, allocation is served
* from the same dynamic area. Might sleep. Might trigger writeouts.
* Allocate zero-filled percpu area of @size bytes aligned at @align
* from reserved percpu area if arch has set it up; otherwise,
* allocation is served from the same dynamic area. Might sleep.
* Might trigger writeouts.
*
* CONTEXT:
* Does GFP_KERNEL allocation.
@ -949,6 +956,7 @@ EXPORT_SYMBOL_GPL(free_percpu);
*/
bool is_kernel_percpu_address(unsigned long addr)
{
#ifdef CONFIG_SMP
const size_t static_size = __per_cpu_end - __per_cpu_start;
void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr);
unsigned int cpu;
@ -959,6 +967,8 @@ bool is_kernel_percpu_address(unsigned long addr)
if ((void *)addr >= start && (void *)addr < start + static_size)
return true;
}
#endif
/* on UP, can't distinguish from other static vars, always false */
return false;
}
@ -1066,6 +1076,321 @@ void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai)
free_bootmem(__pa(ai), ai->__ai_size);
}
/**
* pcpu_dump_alloc_info - print out information about pcpu_alloc_info
* @lvl: loglevel
* @ai: allocation info to dump
*
* Print out information about @ai using loglevel @lvl.
*/
static void pcpu_dump_alloc_info(const char *lvl,
const struct pcpu_alloc_info *ai)
{
int group_width = 1, cpu_width = 1, width;
char empty_str[] = "--------";
int alloc = 0, alloc_end = 0;
int group, v;
int upa, apl; /* units per alloc, allocs per line */
v = ai->nr_groups;
while (v /= 10)
group_width++;
v = num_possible_cpus();
while (v /= 10)
cpu_width++;
empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0';
upa = ai->alloc_size / ai->unit_size;
width = upa * (cpu_width + 1) + group_width + 3;
apl = rounddown_pow_of_two(max(60 / width, 1));
printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu",
lvl, ai->static_size, ai->reserved_size, ai->dyn_size,
ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size);
for (group = 0; group < ai->nr_groups; group++) {
const struct pcpu_group_info *gi = &ai->groups[group];
int unit = 0, unit_end = 0;
BUG_ON(gi->nr_units % upa);
for (alloc_end += gi->nr_units / upa;
alloc < alloc_end; alloc++) {
if (!(alloc % apl)) {
printk("\n");
printk("%spcpu-alloc: ", lvl);
}
printk("[%0*d] ", group_width, group);
for (unit_end += upa; unit < unit_end; unit++)
if (gi->cpu_map[unit] != NR_CPUS)
printk("%0*d ", cpu_width,
gi->cpu_map[unit]);
else
printk("%s ", empty_str);
}
}
printk("\n");
}
/**
* pcpu_setup_first_chunk - initialize the first percpu chunk
* @ai: pcpu_alloc_info describing how to percpu area is shaped
* @base_addr: mapped address
*
* Initialize the first percpu chunk which contains the kernel static
* perpcu area. This function is to be called from arch percpu area
* setup path.
*
* @ai contains all information necessary to initialize the first
* chunk and prime the dynamic percpu allocator.
*
* @ai->static_size is the size of static percpu area.
*
* @ai->reserved_size, if non-zero, specifies the amount of bytes to
* reserve after the static area in the first chunk. This reserves
* the first chunk such that it's available only through reserved
* percpu allocation. This is primarily used to serve module percpu
* static areas on architectures where the addressing model has
* limited offset range for symbol relocations to guarantee module
* percpu symbols fall inside the relocatable range.
*
* @ai->dyn_size determines the number of bytes available for dynamic
* allocation in the first chunk. The area between @ai->static_size +
* @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused.
*
* @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE
* and equal to or larger than @ai->static_size + @ai->reserved_size +
* @ai->dyn_size.
*
* @ai->atom_size is the allocation atom size and used as alignment
* for vm areas.
*
* @ai->alloc_size is the allocation size and always multiple of
* @ai->atom_size. This is larger than @ai->atom_size if
* @ai->unit_size is larger than @ai->atom_size.
*
* @ai->nr_groups and @ai->groups describe virtual memory layout of
* percpu areas. Units which should be colocated are put into the
* same group. Dynamic VM areas will be allocated according to these
* groupings. If @ai->nr_groups is zero, a single group containing
* all units is assumed.
*
* The caller should have mapped the first chunk at @base_addr and
* copied static data to each unit.
*
* If the first chunk ends up with both reserved and dynamic areas, it
* is served by two chunks - one to serve the core static and reserved
* areas and the other for the dynamic area. They share the same vm
* and page map but uses different area allocation map to stay away
* from each other. The latter chunk is circulated in the chunk slots
* and available for dynamic allocation like any other chunks.
*
* RETURNS:
* 0 on success, -errno on failure.
*/
int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
void *base_addr)
{
static char cpus_buf[4096] __initdata;
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;
unsigned long *group_offsets;
size_t *group_sizes;
unsigned long *unit_off;
unsigned int cpu;
int *unit_map;
int group, unit, i;
cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask);
#define PCPU_SETUP_BUG_ON(cond) do { \
if (unlikely(cond)) { \
pr_emerg("PERCPU: failed to initialize, %s", #cond); \
pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf); \
pcpu_dump_alloc_info(KERN_EMERG, ai); \
BUG(); \
} \
} while (0)
/* sanity checks */
PCPU_SETUP_BUG_ON(ai->nr_groups <= 0);
#ifdef CONFIG_SMP
PCPU_SETUP_BUG_ON(!ai->static_size);
#endif
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 */
group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0]));
group_sizes = alloc_bootmem(ai->nr_groups * sizeof(group_sizes[0]));
unit_map = alloc_bootmem(nr_cpu_ids * sizeof(unit_map[0]));
unit_off = alloc_bootmem(nr_cpu_ids * sizeof(unit_off[0]));
for (cpu = 0; cpu < nr_cpu_ids; cpu++)
unit_map[cpu] = UINT_MAX;
pcpu_first_unit_cpu = NR_CPUS;
for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) {
const struct pcpu_group_info *gi = &ai->groups[group];
group_offsets[group] = gi->base_offset;
group_sizes[group] = gi->nr_units * ai->unit_size;
for (i = 0; i < gi->nr_units; i++) {
cpu = gi->cpu_map[i];
if (cpu == NR_CPUS)
continue;
PCPU_SETUP_BUG_ON(cpu > nr_cpu_ids);
PCPU_SETUP_BUG_ON(!cpu_possible(cpu));
PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX);
unit_map[cpu] = unit + i;
unit_off[cpu] = gi->base_offset + i * ai->unit_size;
if (pcpu_first_unit_cpu == NR_CPUS)
pcpu_first_unit_cpu = cpu;
pcpu_last_unit_cpu = cpu;
}
}
pcpu_nr_units = unit;
for_each_possible_cpu(cpu)
PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX);
/* we're done parsing the input, undefine BUG macro and dump config */
#undef PCPU_SETUP_BUG_ON
pcpu_dump_alloc_info(KERN_INFO, ai);
pcpu_nr_groups = ai->nr_groups;
pcpu_group_offsets = group_offsets;
pcpu_group_sizes = group_sizes;
pcpu_unit_map = unit_map;
pcpu_unit_offsets = unit_off;
/* determine basic parameters */
pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT;
pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT;
pcpu_atom_size = ai->atom_size;
pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) +
BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long);
/*
* Allocate chunk slots. The additional last slot is for
* empty chunks.
*/
pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2;
pcpu_slot = alloc_bootmem(pcpu_nr_slots * sizeof(pcpu_slot[0]));
for (i = 0; i < pcpu_nr_slots; i++)
INIT_LIST_HEAD(&pcpu_slot[i]);
/*
* Initialize static chunk. If reserved_size is zero, the
* static chunk covers static area + dynamic allocation area
* in the first chunk. If reserved_size is not zero, it
* covers static area + reserved area (mostly used for module
* static percpu allocation).
*/
schunk = alloc_bootmem(pcpu_chunk_struct_size);
INIT_LIST_HEAD(&schunk->list);
schunk->base_addr = base_addr;
schunk->map = smap;
schunk->map_alloc = ARRAY_SIZE(smap);
schunk->immutable = true;
bitmap_fill(schunk->populated, pcpu_unit_pages);
if (ai->reserved_size) {
schunk->free_size = ai->reserved_size;
pcpu_reserved_chunk = schunk;
pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size;
} else {
schunk->free_size = dyn_size;
dyn_size = 0; /* dynamic area covered */
}
schunk->contig_hint = schunk->free_size;
schunk->map[schunk->map_used++] = -ai->static_size;
if (schunk->free_size)
schunk->map[schunk->map_used++] = schunk->free_size;
/* init dynamic chunk if necessary */
if (dyn_size) {
dchunk = alloc_bootmem(pcpu_chunk_struct_size);
INIT_LIST_HEAD(&dchunk->list);
dchunk->base_addr = base_addr;
dchunk->map = dmap;
dchunk->map_alloc = ARRAY_SIZE(dmap);
dchunk->immutable = true;
bitmap_fill(dchunk->populated, pcpu_unit_pages);
dchunk->contig_hint = dchunk->free_size = dyn_size;
dchunk->map[dchunk->map_used++] = -pcpu_reserved_chunk_limit;
dchunk->map[dchunk->map_used++] = dchunk->free_size;
}
/* link the first chunk in */
pcpu_first_chunk = dchunk ?: schunk;
pcpu_chunk_relocate(pcpu_first_chunk, -1);
/* we're done */
pcpu_base_addr = base_addr;
return 0;
}
#ifdef CONFIG_SMP
const char *pcpu_fc_names[PCPU_FC_NR] __initdata = {
[PCPU_FC_AUTO] = "auto",
[PCPU_FC_EMBED] = "embed",
[PCPU_FC_PAGE] = "page",
};
enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO;
static int __init percpu_alloc_setup(char *str)
{
if (0)
/* nada */;
#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
else if (!strcmp(str, "embed"))
pcpu_chosen_fc = PCPU_FC_EMBED;
#endif
#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
else if (!strcmp(str, "page"))
pcpu_chosen_fc = PCPU_FC_PAGE;
#endif
else
pr_warning("PERCPU: unknown allocator %s specified\n", str);
return 0;
}
early_param("percpu_alloc", percpu_alloc_setup);
/*
* pcpu_embed_first_chunk() is used by the generic percpu setup.
* Build it if needed by the arch config or the generic setup is going
* to be used.
*/
#if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \
!defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
#define BUILD_EMBED_FIRST_CHUNK
#endif
/* build pcpu_page_first_chunk() iff needed by the arch config */
#if defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK)
#define BUILD_PAGE_FIRST_CHUNK
#endif
/* pcpu_build_alloc_info() is used by both embed and page first chunk */
#if defined(BUILD_EMBED_FIRST_CHUNK) || defined(BUILD_PAGE_FIRST_CHUNK)
/**
* pcpu_build_alloc_info - build alloc_info considering distances between CPUs
* @reserved_size: the size of reserved percpu area in bytes
@ -1220,303 +1545,9 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info(
return ai;
}
#endif /* BUILD_EMBED_FIRST_CHUNK || BUILD_PAGE_FIRST_CHUNK */
/**
* pcpu_dump_alloc_info - print out information about pcpu_alloc_info
* @lvl: loglevel
* @ai: allocation info to dump
*
* Print out information about @ai using loglevel @lvl.
*/
static void pcpu_dump_alloc_info(const char *lvl,
const struct pcpu_alloc_info *ai)
{
int group_width = 1, cpu_width = 1, width;
char empty_str[] = "--------";
int alloc = 0, alloc_end = 0;
int group, v;
int upa, apl; /* units per alloc, allocs per line */
v = ai->nr_groups;
while (v /= 10)
group_width++;
v = num_possible_cpus();
while (v /= 10)
cpu_width++;
empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0';
upa = ai->alloc_size / ai->unit_size;
width = upa * (cpu_width + 1) + group_width + 3;
apl = rounddown_pow_of_two(max(60 / width, 1));
printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu",
lvl, ai->static_size, ai->reserved_size, ai->dyn_size,
ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size);
for (group = 0; group < ai->nr_groups; group++) {
const struct pcpu_group_info *gi = &ai->groups[group];
int unit = 0, unit_end = 0;
BUG_ON(gi->nr_units % upa);
for (alloc_end += gi->nr_units / upa;
alloc < alloc_end; alloc++) {
if (!(alloc % apl)) {
printk("\n");
printk("%spcpu-alloc: ", lvl);
}
printk("[%0*d] ", group_width, group);
for (unit_end += upa; unit < unit_end; unit++)
if (gi->cpu_map[unit] != NR_CPUS)
printk("%0*d ", cpu_width,
gi->cpu_map[unit]);
else
printk("%s ", empty_str);
}
}
printk("\n");
}
/**
* pcpu_setup_first_chunk - initialize the first percpu chunk
* @ai: pcpu_alloc_info describing how to percpu area is shaped
* @base_addr: mapped address
*
* Initialize the first percpu chunk which contains the kernel static
* perpcu area. This function is to be called from arch percpu area
* setup path.
*
* @ai contains all information necessary to initialize the first
* chunk and prime the dynamic percpu allocator.
*
* @ai->static_size is the size of static percpu area.
*
* @ai->reserved_size, if non-zero, specifies the amount of bytes to
* reserve after the static area in the first chunk. This reserves
* the first chunk such that it's available only through reserved
* percpu allocation. This is primarily used to serve module percpu
* static areas on architectures where the addressing model has
* limited offset range for symbol relocations to guarantee module
* percpu symbols fall inside the relocatable range.
*
* @ai->dyn_size determines the number of bytes available for dynamic
* allocation in the first chunk. The area between @ai->static_size +
* @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused.
*
* @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE
* and equal to or larger than @ai->static_size + @ai->reserved_size +
* @ai->dyn_size.
*
* @ai->atom_size is the allocation atom size and used as alignment
* for vm areas.
*
* @ai->alloc_size is the allocation size and always multiple of
* @ai->atom_size. This is larger than @ai->atom_size if
* @ai->unit_size is larger than @ai->atom_size.
*
* @ai->nr_groups and @ai->groups describe virtual memory layout of
* percpu areas. Units which should be colocated are put into the
* same group. Dynamic VM areas will be allocated according to these
* groupings. If @ai->nr_groups is zero, a single group containing
* all units is assumed.
*
* The caller should have mapped the first chunk at @base_addr and
* copied static data to each unit.
*
* If the first chunk ends up with both reserved and dynamic areas, it
* is served by two chunks - one to serve the core static and reserved
* areas and the other for the dynamic area. They share the same vm
* and page map but uses different area allocation map to stay away
* from each other. The latter chunk is circulated in the chunk slots
* and available for dynamic allocation like any other chunks.
*
* RETURNS:
* 0 on success, -errno on failure.
*/
int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
void *base_addr)
{
static char cpus_buf[4096] __initdata;
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;
unsigned long *group_offsets;
size_t *group_sizes;
unsigned long *unit_off;
unsigned int cpu;
int *unit_map;
int group, unit, i;
cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask);
#define PCPU_SETUP_BUG_ON(cond) do { \
if (unlikely(cond)) { \
pr_emerg("PERCPU: failed to initialize, %s", #cond); \
pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf); \
pcpu_dump_alloc_info(KERN_EMERG, ai); \
BUG(); \
} \
} while (0)
/* sanity checks */
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 */
group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0]));
group_sizes = alloc_bootmem(ai->nr_groups * sizeof(group_sizes[0]));
unit_map = alloc_bootmem(nr_cpu_ids * sizeof(unit_map[0]));
unit_off = alloc_bootmem(nr_cpu_ids * sizeof(unit_off[0]));
for (cpu = 0; cpu < nr_cpu_ids; cpu++)
unit_map[cpu] = UINT_MAX;
pcpu_first_unit_cpu = NR_CPUS;
for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) {
const struct pcpu_group_info *gi = &ai->groups[group];
group_offsets[group] = gi->base_offset;
group_sizes[group] = gi->nr_units * ai->unit_size;
for (i = 0; i < gi->nr_units; i++) {
cpu = gi->cpu_map[i];
if (cpu == NR_CPUS)
continue;
PCPU_SETUP_BUG_ON(cpu > nr_cpu_ids);
PCPU_SETUP_BUG_ON(!cpu_possible(cpu));
PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX);
unit_map[cpu] = unit + i;
unit_off[cpu] = gi->base_offset + i * ai->unit_size;
if (pcpu_first_unit_cpu == NR_CPUS)
pcpu_first_unit_cpu = cpu;
pcpu_last_unit_cpu = cpu;
}
}
pcpu_nr_units = unit;
for_each_possible_cpu(cpu)
PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX);
/* we're done parsing the input, undefine BUG macro and dump config */
#undef PCPU_SETUP_BUG_ON
pcpu_dump_alloc_info(KERN_INFO, ai);
pcpu_nr_groups = ai->nr_groups;
pcpu_group_offsets = group_offsets;
pcpu_group_sizes = group_sizes;
pcpu_unit_map = unit_map;
pcpu_unit_offsets = unit_off;
/* determine basic parameters */
pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT;
pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT;
pcpu_atom_size = ai->atom_size;
pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) +
BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long);
/*
* Allocate chunk slots. The additional last slot is for
* empty chunks.
*/
pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2;
pcpu_slot = alloc_bootmem(pcpu_nr_slots * sizeof(pcpu_slot[0]));
for (i = 0; i < pcpu_nr_slots; i++)
INIT_LIST_HEAD(&pcpu_slot[i]);
/*
* Initialize static chunk. If reserved_size is zero, the
* static chunk covers static area + dynamic allocation area
* in the first chunk. If reserved_size is not zero, it
* covers static area + reserved area (mostly used for module
* static percpu allocation).
*/
schunk = alloc_bootmem(pcpu_chunk_struct_size);
INIT_LIST_HEAD(&schunk->list);
schunk->base_addr = base_addr;
schunk->map = smap;
schunk->map_alloc = ARRAY_SIZE(smap);
schunk->immutable = true;
bitmap_fill(schunk->populated, pcpu_unit_pages);
if (ai->reserved_size) {
schunk->free_size = ai->reserved_size;
pcpu_reserved_chunk = schunk;
pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size;
} else {
schunk->free_size = dyn_size;
dyn_size = 0; /* dynamic area covered */
}
schunk->contig_hint = schunk->free_size;
schunk->map[schunk->map_used++] = -ai->static_size;
if (schunk->free_size)
schunk->map[schunk->map_used++] = schunk->free_size;
/* init dynamic chunk if necessary */
if (dyn_size) {
dchunk = alloc_bootmem(pcpu_chunk_struct_size);
INIT_LIST_HEAD(&dchunk->list);
dchunk->base_addr = base_addr;
dchunk->map = dmap;
dchunk->map_alloc = ARRAY_SIZE(dmap);
dchunk->immutable = true;
bitmap_fill(dchunk->populated, pcpu_unit_pages);
dchunk->contig_hint = dchunk->free_size = dyn_size;
dchunk->map[dchunk->map_used++] = -pcpu_reserved_chunk_limit;
dchunk->map[dchunk->map_used++] = dchunk->free_size;
}
/* link the first chunk in */
pcpu_first_chunk = dchunk ?: schunk;
pcpu_chunk_relocate(pcpu_first_chunk, -1);
/* we're done */
pcpu_base_addr = base_addr;
return 0;
}
const char *pcpu_fc_names[PCPU_FC_NR] __initdata = {
[PCPU_FC_AUTO] = "auto",
[PCPU_FC_EMBED] = "embed",
[PCPU_FC_PAGE] = "page",
};
enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO;
static int __init percpu_alloc_setup(char *str)
{
if (0)
/* nada */;
#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
else if (!strcmp(str, "embed"))
pcpu_chosen_fc = PCPU_FC_EMBED;
#endif
#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
else if (!strcmp(str, "page"))
pcpu_chosen_fc = PCPU_FC_PAGE;
#endif
else
pr_warning("PERCPU: unknown allocator %s specified\n", str);
return 0;
}
early_param("percpu_alloc", percpu_alloc_setup);
#if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \
!defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
#if defined(BUILD_EMBED_FIRST_CHUNK)
/**
* pcpu_embed_first_chunk - embed the first percpu chunk into bootmem
* @reserved_size: the size of reserved percpu area in bytes
@ -1645,10 +1676,9 @@ out_free:
free_bootmem(__pa(areas), areas_size);
return rc;
}
#endif /* CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK ||
!CONFIG_HAVE_SETUP_PER_CPU_AREA */
#endif /* BUILD_EMBED_FIRST_CHUNK */
#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
#ifdef BUILD_PAGE_FIRST_CHUNK
/**
* pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages
* @reserved_size: the size of reserved percpu area in bytes
@ -1756,10 +1786,11 @@ out_free_ar:
pcpu_free_alloc_info(ai);
return rc;
}
#endif /* CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK */
#endif /* BUILD_PAGE_FIRST_CHUNK */
#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
/*
* Generic percpu area setup.
* Generic SMP percpu area setup.
*
* The embedding helper is used because its behavior closely resembles
* the original non-dynamic generic percpu area setup. This is
@ -1770,7 +1801,6 @@ out_free_ar:
* on the physical linear memory mapping which uses large page
* mappings on applicable archs.
*/
#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
EXPORT_SYMBOL(__per_cpu_offset);
@ -1799,13 +1829,48 @@ void __init setup_per_cpu_areas(void)
PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL,
pcpu_dfl_fc_alloc, pcpu_dfl_fc_free);
if (rc < 0)
panic("Failed to initialized percpu areas.");
panic("Failed to initialize percpu areas.");
delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
for_each_possible_cpu(cpu)
__per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
}
#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
#else /* CONFIG_SMP */
/*
* UP percpu area setup.
*
* UP always uses km-based percpu allocator with identity mapping.
* Static percpu variables are indistinguishable from the usual static
* variables and don't require any special preparation.
*/
void __init setup_per_cpu_areas(void)
{
const size_t unit_size =
roundup_pow_of_two(max_t(size_t, PCPU_MIN_UNIT_SIZE,
PERCPU_DYNAMIC_RESERVE));
struct pcpu_alloc_info *ai;
void *fc;
ai = pcpu_alloc_alloc_info(1, 1);
fc = __alloc_bootmem(unit_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
if (!ai || !fc)
panic("Failed to allocate memory for percpu areas.");
ai->dyn_size = unit_size;
ai->unit_size = unit_size;
ai->atom_size = unit_size;
ai->alloc_size = unit_size;
ai->groups[0].nr_units = 1;
ai->groups[0].cpu_map[0] = 0;
if (pcpu_setup_first_chunk(ai, fc) < 0)
panic("Failed to initialize percpu areas.");
}
#endif /* CONFIG_SMP */
/*
* First and reserved chunks are initialized with temporary allocation

30
mm/percpu_up.c
View File

@ -1,30 +0,0 @@
/*
* mm/percpu_up.c - dummy percpu memory allocator implementation for UP
*/
#include <linux/module.h>
#include <linux/percpu.h>
#include <linux/slab.h>
void __percpu *__alloc_percpu(size_t size, size_t align)
{
/*
* Can't easily make larger alignment work with kmalloc. WARN
* on it. Larger alignment should only be used for module
* percpu sections on SMP for which this path isn't used.
*/
WARN_ON_ONCE(align > SMP_CACHE_BYTES);
return (void __percpu __force *)kzalloc(size, GFP_KERNEL);
}
EXPORT_SYMBOL_GPL(__alloc_percpu);
void free_percpu(void __percpu *p)
{
kfree(this_cpu_ptr(p));
}
EXPORT_SYMBOL_GPL(free_percpu);
phys_addr_t per_cpu_ptr_to_phys(void *addr)
{
return __pa(addr);
}

2
mm/vmalloc.c
View File

@ -2065,6 +2065,7 @@ void free_vm_area(struct vm_struct *area)
}
EXPORT_SYMBOL_GPL(free_vm_area);
#ifdef CONFIG_SMP
static struct vmap_area *node_to_va(struct rb_node *n)
{
return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
@ -2345,6 +2346,7 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
free_vm_area(vms[i]);
kfree(vms);
}
#endif /* CONFIG_SMP */
#ifdef CONFIG_PROC_FS
static void *s_start(struct seq_file *m, loff_t *pos)