percpu: use pcpu_free_slot instead of pcpu_nr_slots - 1

This prepares for adding a to_depopulate list and sidelined list after
the free slot in the set of lists in pcpu_slot.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
This commit is contained in:
Dennis Zhou 2021-04-18 22:44:16 +00:00
parent 8ea2e1e35d
commit 1c29a3ceaf

View File

@ -135,6 +135,7 @@ static int pcpu_unit_size __ro_after_init;
static int pcpu_nr_units __ro_after_init;
static int pcpu_atom_size __ro_after_init;
int pcpu_nr_slots __ro_after_init;
int pcpu_free_slot __ro_after_init;
static size_t pcpu_chunk_struct_size __ro_after_init;
/* cpus with the lowest and highest unit addresses */
@ -237,7 +238,7 @@ static int __pcpu_size_to_slot(int size)
static int pcpu_size_to_slot(int size)
{
if (size == pcpu_unit_size)
return pcpu_nr_slots - 1;
return pcpu_free_slot;
return __pcpu_size_to_slot(size);
}
@ -1806,7 +1807,7 @@ restart:
goto fail;
}
if (list_empty(&pcpu_slot[pcpu_nr_slots - 1])) {
if (list_empty(&pcpu_slot[pcpu_free_slot])) {
chunk = pcpu_create_chunk(type, pcpu_gfp);
if (!chunk) {
err = "failed to allocate new chunk";
@ -1958,7 +1959,7 @@ static void pcpu_balance_free(enum pcpu_chunk_type type)
{
LIST_HEAD(to_free);
struct list_head *pcpu_slot = pcpu_chunk_list(type);
struct list_head *free_head = &pcpu_slot[pcpu_nr_slots - 1];
struct list_head *free_head = &pcpu_slot[pcpu_free_slot];
struct pcpu_chunk *chunk, *next;
/*
@ -2033,7 +2034,7 @@ retry_pop:
0, PCPU_EMPTY_POP_PAGES_HIGH);
}
for (slot = pcpu_size_to_slot(PAGE_SIZE); slot < pcpu_nr_slots; slot++) {
for (slot = pcpu_size_to_slot(PAGE_SIZE); slot <= pcpu_free_slot; slot++) {
unsigned int nr_unpop = 0, rs, re;
if (!nr_to_pop)
@ -2140,7 +2141,7 @@ void free_percpu(void __percpu *ptr)
if (chunk->free_bytes == pcpu_unit_size) {
struct pcpu_chunk *pos;
list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list)
list_for_each_entry(pos, &pcpu_slot[pcpu_free_slot], list)
if (pos != chunk) {
need_balance = true;
break;
@ -2562,7 +2563,8 @@ void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
* Allocate chunk slots. The additional last slot is for
* empty chunks.
*/
pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2;
pcpu_free_slot = __pcpu_size_to_slot(pcpu_unit_size) + 1;
pcpu_nr_slots = pcpu_free_slot + 1;
pcpu_chunk_lists = memblock_alloc(pcpu_nr_slots *
sizeof(pcpu_chunk_lists[0]) *
PCPU_NR_CHUNK_TYPES,