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

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: make allocation failures more verbose
  percpu: make pcpu_setup_first_chunk() failures more verbose
  percpu: make embedding first chunk allocator check vmalloc space size
  sparc64: implement page mapping percpu first chunk allocator
  percpu: make pcpu_build_alloc_info() clear static buffers
  percpu: fix unit_map[] verification in pcpu_setup_first_chunk()
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@torvalds
torvalds committed Sep 30, 2009
2 parents 8c11499 + f2badb0 commit 07892ac
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Showing 3 changed files with 114 additions and 25 deletions.
3 changes: 3 additions & 0 deletions arch/sparc/Kconfig
View file
Expand Up @@ -102,6 +102,9 @@ config HAVE_SETUP_PER_CPU_AREA
config NEED_PER_CPU_EMBED_FIRST_CHUNK
def_bool y if SPARC64

config NEED_PER_CPU_PAGE_FIRST_CHUNK
def_bool y if SPARC64

config GENERIC_HARDIRQS_NO__DO_IRQ
bool
def_bool y if SPARC64
Expand Down
53 changes: 44 additions & 9 deletions arch/sparc/kernel/smp_64.c
View file
Expand Up @@ -1420,26 +1420,61 @@ static void __init pcpu_free_bootmem(void *ptr, size_t size)
free_bootmem(__pa(ptr), size);
}

static int pcpu_cpu_distance(unsigned int from, unsigned int to)
static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
{
if (cpu_to_node(from) == cpu_to_node(to))
return LOCAL_DISTANCE;
else
return REMOTE_DISTANCE;
}

static void __init pcpu_populate_pte(unsigned long addr)
{
pgd_t *pgd = pgd_offset_k(addr);
pud_t *pud;
pmd_t *pmd;

pud = pud_offset(pgd, addr);
if (pud_none(*pud)) {
pmd_t *new;

new = __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);
pud_populate(&init_mm, pud, new);
}

pmd = pmd_offset(pud, addr);
if (!pmd_present(*pmd)) {
pte_t *new;

new = __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);
pmd_populate_kernel(&init_mm, pmd, new);
}
}

void __init setup_per_cpu_areas(void)
{
unsigned long delta;
unsigned int cpu;
int rc;

rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
PERCPU_DYNAMIC_RESERVE, 4 << 20,
pcpu_cpu_distance, pcpu_alloc_bootmem,
pcpu_free_bootmem);
if (rc)
panic("failed to initialize first chunk (%d)", rc);
int rc = -EINVAL;

if (pcpu_chosen_fc != PCPU_FC_PAGE) {
rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
PERCPU_DYNAMIC_RESERVE, 4 << 20,
pcpu_cpu_distance,
pcpu_alloc_bootmem,
pcpu_free_bootmem);
if (rc)
pr_warning("PERCPU: %s allocator failed (%d), "
"falling back to page size\n",
pcpu_fc_names[pcpu_chosen_fc], rc);
}
if (rc < 0)
rc = pcpu_page_first_chunk(PERCPU_MODULE_RESERVE,
pcpu_alloc_bootmem,
pcpu_free_bootmem,
pcpu_populate_pte);
if (rc < 0)
panic("cannot initialize percpu area (err=%d)", rc);

delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
for_each_possible_cpu(cpu)
Expand Down
83 changes: 67 additions & 16 deletions mm/percpu.c
View file
Expand Up @@ -1043,7 +1043,9 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void)
*/
static void *pcpu_alloc(size_t size, size_t align, bool reserved)
{
static int warn_limit = 10;
struct pcpu_chunk *chunk;
const char *err;
int slot, off;

if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) {
Expand All @@ -1059,11 +1061,14 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
if (reserved && pcpu_reserved_chunk) {
chunk = pcpu_reserved_chunk;
if (size > chunk->contig_hint ||
pcpu_extend_area_map(chunk) < 0)
pcpu_extend_area_map(chunk) < 0) {
err = "failed to extend area map of reserved chunk";
goto fail_unlock;
}
off = pcpu_alloc_area(chunk, size, align);
if (off >= 0)
goto area_found;
err = "alloc from reserved chunk failed";
goto fail_unlock;
}

Expand All @@ -1080,6 +1085,7 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
case 1:
goto restart; /* pcpu_lock dropped, restart */
default:
err = "failed to extend area map";
goto fail_unlock;
}

Expand All @@ -1093,8 +1099,10 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
spin_unlock_irq(&pcpu_lock);

chunk = alloc_pcpu_chunk();
if (!chunk)
if (!chunk) {
err = "failed to allocate new chunk";
goto fail_unlock_mutex;
}

spin_lock_irq(&pcpu_lock);
pcpu_chunk_relocate(chunk, -1);
Expand All @@ -1107,6 +1115,7 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
if (pcpu_populate_chunk(chunk, off, size)) {
spin_lock_irq(&pcpu_lock);
pcpu_free_area(chunk, off);
err = "failed to populate";
goto fail_unlock;
}

Expand All @@ -1119,6 +1128,13 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
spin_unlock_irq(&pcpu_lock);
fail_unlock_mutex:
mutex_unlock(&pcpu_alloc_mutex);
if (warn_limit) {
pr_warning("PERCPU: allocation failed, size=%zu align=%zu, "
"%s\n", size, align, err);
dump_stack();
if (!--warn_limit)
pr_info("PERCPU: limit reached, disable warning\n");
}
return NULL;
}

Expand Down Expand Up @@ -1347,6 +1363,10 @@ struct pcpu_alloc_info * __init pcpu_build_alloc_info(
struct pcpu_alloc_info *ai;
unsigned int *cpu_map;

/* this function may be called multiple times */
memset(group_map, 0, sizeof(group_map));
memset(group_cnt, 0, sizeof(group_map));

/*
* Determine min_unit_size, alloc_size and max_upa such that
* alloc_size is multiple of atom_size and is the smallest
Expand Down Expand Up @@ -1574,6 +1594,7 @@ static void pcpu_dump_alloc_info(const char *lvl,
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];
size_t dyn_size = ai->dyn_size;
size_t size_sum = ai->static_size + ai->reserved_size + dyn_size;
Expand All @@ -1585,17 +1606,26 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
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 */
BUILD_BUG_ON(ARRAY_SIZE(smap) >= PCPU_DFL_MAP_ALLOC ||
ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC);
BUG_ON(ai->nr_groups <= 0);
BUG_ON(!ai->static_size);
BUG_ON(!base_addr);
BUG_ON(ai->unit_size < size_sum);
BUG_ON(ai->unit_size & ~PAGE_MASK);
BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE);

pcpu_dump_alloc_info(KERN_DEBUG, ai);
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);

/* process group information and build config tables accordingly */
group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0]));
Expand All @@ -1604,7 +1634,7 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
unit_off = alloc_bootmem(nr_cpu_ids * sizeof(unit_off[0]));

for (cpu = 0; cpu < nr_cpu_ids; cpu++)
unit_map[cpu] = NR_CPUS;
unit_map[cpu] = UINT_MAX;
pcpu_first_unit_cpu = NR_CPUS;

for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) {
Expand All @@ -1618,8 +1648,9 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
if (cpu == NR_CPUS)
continue;

BUG_ON(cpu > nr_cpu_ids || !cpu_possible(cpu));
BUG_ON(unit_map[cpu] != NR_CPUS);
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;
Expand All @@ -1632,7 +1663,11 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
pcpu_nr_units = unit;

for_each_possible_cpu(cpu)
BUG_ON(unit_map[cpu] == NR_CPUS);
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;
Expand Down Expand Up @@ -1782,7 +1817,7 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size,
void *base = (void *)ULONG_MAX;
void **areas = NULL;
struct pcpu_alloc_info *ai;
size_t size_sum, areas_size;
size_t size_sum, areas_size, max_distance;
int group, i, rc;

ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size,
Expand Down Expand Up @@ -1832,8 +1867,24 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size,
}

/* base address is now known, determine group base offsets */
for (group = 0; group < ai->nr_groups; group++)
max_distance = 0;
for (group = 0; group < ai->nr_groups; group++) {
ai->groups[group].base_offset = areas[group] - base;
max_distance = max(max_distance, ai->groups[group].base_offset);
}
max_distance += ai->unit_size;

/* warn if maximum distance is further than 75% of vmalloc space */
if (max_distance > (VMALLOC_END - VMALLOC_START) * 3 / 4) {
pr_warning("PERCPU: max_distance=0x%lx too large for vmalloc "
"space 0x%lx\n",
max_distance, VMALLOC_END - VMALLOC_START);
#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
/* and fail if we have fallback */
rc = -EINVAL;
goto out_free;
#endif
}

pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n",
PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size,
Expand Down

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