From 7ee1e758bebe13d96217bcfd5230892ed44760e7 Mon Sep 17 00:00:00 2001 From: Baoquan He Date: Sat, 22 Jul 2023 09:14:37 +0800 Subject: 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 [Dennis: reworded first chunk init comment] Signed-off-by: Dennis Zhou --- mm/percpu.c | 38 +++++++++++++++----------------------- 1 file changed, 15 insertions(+), 23 deletions(-) (limited to 'mm/percpu.c') diff --git a/mm/percpu.c b/mm/percpu.c index 93b1bec2b28d..ab4ba2ac91c7 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -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); - - /* 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); - } + 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); - /* 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); -- cgit