Commit f1180fd2 authored by Wei Yang's avatar Wei Yang Committed by Mike Rapoport (IBM)
Browse files

mm/mm_init.c: not always search next deferred_init_pfn from very beginning 



In function deferred_init_memmap(), we call
deferred_init_mem_pfn_range_in_zone() to get the next deferred_init_pfn.
But we always search it from the very beginning.

Since we save the index in i, we can leverage this to search from i next
time.

[rppt refine the comment]

Signed-off-by: default avatarWei Yang <richard.weiyang@gmail.com>
Link: https://lore.kernel.org/all/20240605071339.15330-1-richard.weiyang@gmail.com


Signed-off-by: default avatarMike Rapoport (IBM) <rppt@kernel.org>
parent 544b8e14

include/linux/memblock.h

+0 −19
Original line number Diff line number Diff line
@@ -299,25 +299,6 @@ void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn, 
void __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone,

				  unsigned long *out_spfn,

				  unsigned long *out_epfn);

/**

 * for_each_free_mem_pfn_range_in_zone - iterate through zone specific free

 * memblock areas

 * @i: u64 used as loop variable

 * @zone: zone in which all of the memory blocks reside

 * @p_start: ptr to phys_addr_t for start address of the range, can be %NULL

 * @p_end: ptr to phys_addr_t for end address of the range, can be %NULL

 *

 * Walks over free (memory && !reserved) areas of memblock in a specific

 * zone. Available once memblock and an empty zone is initialized. The main

 * assumption is that the zone start, end, and pgdat have been associated.

 * This way we can use the zone to determine NUMA node, and if a given part

 * of the memblock is valid for the zone.

 */

#define for_each_free_mem_pfn_range_in_zone(i, zone, p_start, p_end)	\

	for (i = 0,							\

	     __next_mem_pfn_range_in_zone(&i, zone, p_start, p_end);	\

	     i != U64_MAX;					\

	     __next_mem_pfn_range_in_zone(&i, zone, p_start, p_end))



/**

 * for_each_free_mem_pfn_range_in_zone_from - iterate through zone specific

mm/mm_init.c

+14 −9
Original line number Diff line number Diff line
@@ -2021,24 +2021,29 @@ static unsigned long __init deferred_init_pages(struct zone *zone, 
}



/*

 * This function is meant to pre-load the iterator for the zone init.

 * Specifically it walks through the ranges until we are caught up to the

 * first_init_pfn value and exits there. If we never encounter the value we

 * return false indicating there are no valid ranges left.

 * This function is meant to pre-load the iterator for the zone init from

 * a given point.

 * Specifically it walks through the ranges starting with initial index

 * passed to it until we are caught up to the first_init_pfn value and

 * exits there. If we never encounter the value we return false indicating

 * there are no valid ranges left.

 */

static bool __init

deferred_init_mem_pfn_range_in_zone(u64 *i, struct zone *zone,

				    unsigned long *spfn, unsigned long *epfn,

				    unsigned long first_init_pfn)

{

	u64 j;

	u64 j = *i;



	if (j == 0)

		__next_mem_pfn_range_in_zone(&j, zone, spfn, epfn);



	/*

	 * Start out by walking through the ranges in this zone that have

	 * already been initialized. We don't need to do anything with them

	 * so we just need to flush them out of the system.

	 */

	for_each_free_mem_pfn_range_in_zone(j, zone, spfn, epfn) {

	for_each_free_mem_pfn_range_in_zone_from(j, zone, spfn, epfn) {

		if (*epfn <= first_init_pfn)

			continue;

		if (*spfn < first_init_pfn)
@@ -2110,7 +2115,7 @@ deferred_init_memmap_chunk(unsigned long start_pfn, unsigned long end_pfn, 
{

	unsigned long spfn, epfn;

	struct zone *zone = arg;

	u64 i;

	u64 i = 0;



	deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn, start_pfn);
@@ -2141,7 +2146,7 @@ static int __init deferred_init_memmap(void *data) 
	unsigned long start = jiffies;

	struct zone *zone;

	int max_threads;

	u64 i;

	u64 i = 0;



	/* Bind memory initialisation thread to a local node if possible */

	if (!cpumask_empty(cpumask))
@@ -2216,7 +2221,7 @@ bool __init deferred_grow_zone(struct zone *zone, unsigned int order) 
	unsigned long first_deferred_pfn = pgdat->first_deferred_pfn;

	unsigned long spfn, epfn, flags;

	unsigned long nr_pages = 0;

	u64 i;

	u64 i = 0;



	/* Only the last zone may have deferred pages */

	if (zone_end_pfn(zone) != pgdat_end_pfn(pgdat))