Commit 7ee1e758 authored by Baoquan He's avatar Baoquan He Committed by Dennis Zhou
Browse files

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: default avatarBaoquan He <bhe@redhat.com>
[Dennis: reworded first chunk init comment]
Signed-off-by: default avatarDennis Zhou <dennis@kernel.org>
parent 5b672085

mm/percpu.c

+15 −23
Original line number Diff line number Diff line
@@ -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);