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Commit 4ba6ce25 authored by Tejun Heo's avatar Tejun Heo
Browse files

percpu: make @dyn_size always mean min dyn_size in first chunk init functions 



In pcpu_build_alloc_info() and pcpu_embed_first_chunk(), @dyn_size was
ssize_t, -1 meant auto-size, 0 forced 0 and positive meant minimum
size.  There's no use case for forcing 0 and the upcoming early alloc
support always requires non-zero dynamic size.  Make @dyn_size always
mean minimum dyn_size.

While at it, make pcpu_build_alloc_info() static which doesn't have
any external caller as suggested by David Rientjes.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: David Rientjes <rientjes@google.com>
parent 9983b6f0

include/linux/percpu.h

+1 −6
Original line number Diff line number Diff line
@@ -104,16 +104,11 @@ extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, 
							     int nr_units);

extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);



extern struct pcpu_alloc_info * __init pcpu_build_alloc_info(

				size_t reserved_size, ssize_t dyn_size,

				size_t atom_size,

				pcpu_fc_cpu_distance_fn_t cpu_distance_fn);



extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,

					 void *base_addr);



#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK

extern int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size,

extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,

				size_t atom_size,

				pcpu_fc_cpu_distance_fn_t cpu_distance_fn,

				pcpu_fc_alloc_fn_t alloc_fn,

mm/percpu.c

+10 −25
Original line number Diff line number Diff line
@@ -1013,20 +1013,6 @@ phys_addr_t per_cpu_ptr_to_phys(void *addr) 
		return page_to_phys(pcpu_addr_to_page(addr));

}



static inline size_t pcpu_calc_fc_sizes(size_t static_size,

					size_t reserved_size,

					ssize_t *dyn_sizep)

{

	size_t size_sum;



	size_sum = PFN_ALIGN(static_size + reserved_size +

			     (*dyn_sizep >= 0 ? *dyn_sizep : 0));

	if (*dyn_sizep != 0)

		*dyn_sizep = size_sum - static_size - reserved_size;



	return size_sum;

}



/**

 * pcpu_alloc_alloc_info - allocate percpu allocation info

 * @nr_groups: the number of groups
@@ -1085,7 +1071,7 @@ void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) 
/**

 * pcpu_build_alloc_info - build alloc_info considering distances between CPUs

 * @reserved_size: the size of reserved percpu area in bytes

 * @dyn_size: free size for dynamic allocation in bytes, -1 for auto

 * @dyn_size: minimum free size for dynamic allocation in bytes

 * @atom_size: allocation atom size

 * @cpu_distance_fn: callback to determine distance between cpus, optional

 *
@@ -1103,8 +1089,8 @@ void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) 
 * On success, pointer to the new allocation_info is returned.  On

 * failure, ERR_PTR value is returned.

 */

struct pcpu_alloc_info * __init pcpu_build_alloc_info(

				size_t reserved_size, ssize_t dyn_size,

static struct pcpu_alloc_info * __init pcpu_build_alloc_info(

				size_t reserved_size, size_t dyn_size,

				size_t atom_size,

				pcpu_fc_cpu_distance_fn_t cpu_distance_fn)

{
@@ -1123,13 +1109,15 @@ struct pcpu_alloc_info * __init pcpu_build_alloc_info( 
	memset(group_map, 0, sizeof(group_map));

	memset(group_cnt, 0, sizeof(group_cnt));



	size_sum = PFN_ALIGN(static_size + reserved_size + dyn_size);

	dyn_size = size_sum - static_size - reserved_size;



	/*

	 * Determine min_unit_size, alloc_size and max_upa such that

	 * alloc_size is multiple of atom_size and is the smallest

	 * which can accomodate 4k aligned segments which are equal to

	 * or larger than min_unit_size.

	 */

	size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, &dyn_size);

	min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE);



	alloc_size = roundup(min_unit_size, atom_size);
@@ -1532,7 +1520,7 @@ early_param("percpu_alloc", percpu_alloc_setup); 
/**

 * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem

 * @reserved_size: the size of reserved percpu area in bytes

 * @dyn_size: free size for dynamic allocation in bytes, -1 for auto

 * @dyn_size: minimum free size for dynamic allocation in bytes

 * @atom_size: allocation atom size

 * @cpu_distance_fn: callback to determine distance between cpus, optional

 * @alloc_fn: function to allocate percpu page
@@ -1553,10 +1541,7 @@ early_param("percpu_alloc", percpu_alloc_setup); 
 * vmalloc space is not orders of magnitude larger than distances

 * between node memory addresses (ie. 32bit NUMA machines).

 *

 * When @dyn_size is positive, dynamic area might be larger than

 * specified to fill page alignment.  When @dyn_size is auto,

 * @dyn_size is just big enough to fill page alignment after static

 * and reserved areas.

 * @dyn_size specifies the minimum dynamic area size.

 *

 * If the needed size is smaller than the minimum or specified unit

 * size, the leftover is returned using @free_fn.
@@ -1564,7 +1549,7 @@ early_param("percpu_alloc", percpu_alloc_setup); 
 * RETURNS:

 * 0 on success, -errno on failure.

 */

int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size,

int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,

				  size_t atom_size,

				  pcpu_fc_cpu_distance_fn_t cpu_distance_fn,

				  pcpu_fc_alloc_fn_t alloc_fn,
@@ -1695,7 +1680,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size, 


	snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10);



	ai = pcpu_build_alloc_info(reserved_size, -1, PAGE_SIZE, NULL);

	ai = pcpu_build_alloc_info(reserved_size, 0, PAGE_SIZE, NULL);

	if (IS_ERR(ai))

		return PTR_ERR(ai);

	BUG_ON(ai->nr_groups != 1);