mm/percpu.c: optimize the code in pcpu_setup_first_chunk() a little bit

This removes the need of local varibale 'chunk', and optimize the code
calling pcpu_alloc_first_chunk() to initialize reserved chunk and
dynamic chunk to make it simpler.

Signed-off-by: Baoquan He <bhe@redhat.com>
[Dennis: reworded first chunk init comment]
Signed-off-by: Dennis Zhou <dennis@kernel.org>
This commit is contained in:
Baoquan He 2023-07-22 09:14:37 +08:00 committed by Dennis Zhou
parent 5b672085e7
commit 7ee1e758be

View File

@ -2581,14 +2581,12 @@ void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
{
size_t size_sum = ai->static_size + ai->reserved_size + ai->dyn_size;
size_t static_size, dyn_size;
struct pcpu_chunk *chunk;
unsigned long *group_offsets;
size_t *group_sizes;
unsigned long *unit_off;
unsigned int cpu;
int *unit_map;
int group, unit, i;
int map_size;
unsigned long tmp_addr;
size_t alloc_size;
@ -2697,7 +2695,7 @@ void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
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 = struct_size(chunk, populated,
pcpu_chunk_struct_size = struct_size((struct pcpu_chunk *)0, populated,
BITS_TO_LONGS(pcpu_unit_pages));
pcpu_stats_save_ai(ai);
@ -2734,29 +2732,23 @@ void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
dyn_size = ai->dyn_size - (static_size - ai->static_size);
/*
* Initialize first chunk.
* If the reserved_size is non-zero, this initializes the reserved
* chunk. If the reserved_size is zero, the reserved chunk is NULL
* and the dynamic region is initialized here. The first chunk,
* pcpu_first_chunk, will always point to the chunk that serves
* the dynamic region.
* Initialize first chunk:
* This chunk is broken up into 3 parts:
* < static | [reserved] | dynamic >
* - static - there is no backing chunk because these allocations can
* never be freed.
* - reserved (pcpu_reserved_chunk) - exists primarily to serve
* allocations from module load.
* - dynamic (pcpu_first_chunk) - serves the dynamic part of the first
* chunk.
*/
tmp_addr = (unsigned long)base_addr + static_size;
map_size = ai->reserved_size ?: dyn_size;
chunk = pcpu_alloc_first_chunk(tmp_addr, map_size);
if (ai->reserved_size)
pcpu_reserved_chunk = pcpu_alloc_first_chunk(tmp_addr,
ai->reserved_size);
tmp_addr = (unsigned long)base_addr + static_size + ai->reserved_size;
pcpu_first_chunk = pcpu_alloc_first_chunk(tmp_addr, dyn_size);
/* init dynamic chunk if necessary */
if (ai->reserved_size) {
pcpu_reserved_chunk = chunk;
tmp_addr = (unsigned long)base_addr + static_size +
ai->reserved_size;
map_size = dyn_size;
chunk = pcpu_alloc_first_chunk(tmp_addr, map_size);
}
/* link the first chunk in */
pcpu_first_chunk = chunk;
pcpu_nr_empty_pop_pages = pcpu_first_chunk->nr_empty_pop_pages;
pcpu_chunk_relocate(pcpu_first_chunk, -1);