Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:mm\percpu.c Create Date:2022-07-28 14:25:51
Last Modify:2022-05-23 13:52:24 Copyright©Brick
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Name:pcpu_next_fit_region - finds fit areas for a given allocation request*@chunk: chunk of interest*@alloc_bits: size of allocation*@align: alignment of area (max PAGE_SIZE)*@bit_off: chunk offset*@bits: size of free area* Finds the next free region that is

Proto:static void pcpu_next_fit_region(struct pcpu_chunk *chunk, int alloc_bits, int align, int *bit_off, int *bits)

Type:void

Parameter:

TypeParameterName
struct pcpu_chunk *chunk
intalloc_bits
intalign
int *bit_off
int *bits
422  i = pcpu_off_to_block_index( * bit_off)
423  block_off = pcpu_off_to_block_off( * bit_off)
426  bits = 0
427  When i < pcpu_chunk_nr_blocks - converts nr_pages to # of md_blocks*@chunk: chunk of interest* This conversion is from the number of physical pages that the chunk* serves to the number of bitmap blocks used. cycle
430  If bits Then
431  bits += size of free space alongthe left side of the block
432  If bits >= alloc_bits Then Return
434  If size of free space alongthe left side of the block == PCPU_BITMAP_BLOCK_BITS Then Continue
439  bits = @a is a power of 2 value (lock relative startingposition of the contig hint , align) - lock relative startingposition of the contig hint
445  If contig hint for block && lock relative startingposition of the contig hint >= block_off && contig hint for block >= bits + alloc_bits Then
448  start = pcpu_next_hint - determine which hint to use*@block: block of interest*@alloc_bits: size of allocation* This determines if we should scan based on the scan_hint or first_free.* In general, we want to scan from first_free to fulfill allocations by
450  bits += alloc_bits + lock relative startingposition of the contig hint - start
452  bit_off = pcpu_block_off_to_off(i, start)
453  Return
456  block_off = 0
458  bit_off = @a is a power of 2 value (PCPU_BITMAP_BLOCK_BITS - size of free space alongthe right side of the block , align)
460  bits = PCPU_BITMAP_BLOCK_BITS - bit_off
461  bit_off = pcpu_block_off_to_off(i, * bit_off)
462  If bits >= alloc_bits Then Return
467  bit_off = pcpu_chunk_map_bits - helper to convert nr_pages to size of bitmap*@chunk: chunk of interest* This conversion is from the number of physical pages that the chunk* serves to the number of bits in the bitmap.