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Diffstat (limited to 'mm/percpu-internal.h')
| -rw-r--r-- | mm/percpu-internal.h | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/mm/percpu-internal.h b/mm/percpu-internal.h new file mode 100644 index 000000000..095d7eaa0 --- /dev/null +++ b/mm/percpu-internal.h @@ -0,0 +1,285 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _MM_PERCPU_INTERNAL_H +#define _MM_PERCPU_INTERNAL_H + +#include <linux/types.h> +#include <linux/percpu.h> + +/* + * There are two chunk types: root and memcg-aware. + * Chunks of each type have separate slots list. + * + * Memcg-aware chunks have an attached vector of obj_cgroup pointers, which is + * used to store memcg membership data of a percpu object. Obj_cgroups are + * ref-counted pointers to a memory cgroup with an ability to switch dynamically + * to the parent memory cgroup. This allows to reclaim a deleted memory cgroup + * without reclaiming of all outstanding objects, which hold a reference at it. + */ +enum pcpu_chunk_type { + PCPU_CHUNK_ROOT, +#ifdef CONFIG_MEMCG_KMEM + PCPU_CHUNK_MEMCG, +#endif + PCPU_NR_CHUNK_TYPES, + PCPU_FAIL_ALLOC = PCPU_NR_CHUNK_TYPES +}; + +/* + * pcpu_block_md is the metadata block struct. + * Each chunk's bitmap is split into a number of full blocks. + * All units are in terms of bits. + * + * The scan hint is the largest known contiguous area before the contig hint. + * It is not necessarily the actual largest contig hint though. There is an + * invariant that the scan_hint_start > contig_hint_start iff + * scan_hint == contig_hint. This is necessary because when scanning forward, + * we don't know if a new contig hint would be better than the current one. + */ +struct pcpu_block_md { + int scan_hint; /* scan hint for block */ + int scan_hint_start; /* block relative starting + position of the scan hint */ + int contig_hint; /* contig hint for block */ + int contig_hint_start; /* block relative starting + position of the contig hint */ + int left_free; /* size of free space along + the left side of the block */ + int right_free; /* size of free space along + the right side of the block */ + int first_free; /* block position of first free */ + int nr_bits; /* total bits responsible for */ +}; + +struct pcpu_chunk { +#ifdef CONFIG_PERCPU_STATS + int nr_alloc; /* # of allocations */ + size_t max_alloc_size; /* largest allocation size */ +#endif + + struct list_head list; /* linked to pcpu_slot lists */ + int free_bytes; /* free bytes in the chunk */ + struct pcpu_block_md chunk_md; + void *base_addr; /* base address of this chunk */ + + unsigned long *alloc_map; /* allocation map */ + unsigned long *bound_map; /* boundary map */ + struct pcpu_block_md *md_blocks; /* metadata blocks */ + + void *data; /* chunk data */ + bool immutable; /* no [de]population allowed */ + int start_offset; /* the overlap with the previous + region to have a page aligned + base_addr */ + int end_offset; /* additional area required to + have the region end page + aligned */ +#ifdef CONFIG_MEMCG_KMEM + struct obj_cgroup **obj_cgroups; /* vector of object cgroups */ +#endif + + int nr_pages; /* # of pages served by this chunk */ + int nr_populated; /* # of populated pages */ + int nr_empty_pop_pages; /* # of empty populated pages */ + unsigned long populated[]; /* populated bitmap */ +}; + +extern spinlock_t pcpu_lock; + +extern struct list_head *pcpu_chunk_lists; +extern int pcpu_nr_slots; +extern int pcpu_nr_empty_pop_pages[]; + +extern struct pcpu_chunk *pcpu_first_chunk; +extern struct pcpu_chunk *pcpu_reserved_chunk; + +/** + * 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. + */ +static inline int pcpu_chunk_nr_blocks(struct pcpu_chunk *chunk) +{ + return chunk->nr_pages * PAGE_SIZE / PCPU_BITMAP_BLOCK_SIZE; +} + +/** + * pcpu_nr_pages_to_map_bits - converts the pages to size of bitmap + * @pages: number of physical pages + * + * This conversion is from physical pages to the number of bits + * required in the bitmap. + */ +static inline int pcpu_nr_pages_to_map_bits(int pages) +{ + return pages * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE; +} + +/** + * 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. + */ +static inline int pcpu_chunk_map_bits(struct pcpu_chunk *chunk) +{ + return pcpu_nr_pages_to_map_bits(chunk->nr_pages); +} + +#ifdef CONFIG_MEMCG_KMEM +static inline enum pcpu_chunk_type pcpu_chunk_type(struct pcpu_chunk *chunk) +{ + if (chunk->obj_cgroups) + return PCPU_CHUNK_MEMCG; + return PCPU_CHUNK_ROOT; +} + +static inline bool pcpu_is_memcg_chunk(enum pcpu_chunk_type chunk_type) +{ + return chunk_type == PCPU_CHUNK_MEMCG; +} + +#else +static inline enum pcpu_chunk_type pcpu_chunk_type(struct pcpu_chunk *chunk) +{ + return PCPU_CHUNK_ROOT; +} + +static inline bool pcpu_is_memcg_chunk(enum pcpu_chunk_type chunk_type) +{ + return false; +} +#endif + +static inline struct list_head *pcpu_chunk_list(enum pcpu_chunk_type chunk_type) +{ + return &pcpu_chunk_lists[pcpu_nr_slots * + pcpu_is_memcg_chunk(chunk_type)]; +} + +#ifdef CONFIG_PERCPU_STATS + +#include <linux/spinlock.h> + +struct percpu_stats { + u64 nr_alloc; /* lifetime # of allocations */ + u64 nr_dealloc; /* lifetime # of deallocations */ + u64 nr_cur_alloc; /* current # of allocations */ + u64 nr_max_alloc; /* max # of live allocations */ + u32 nr_chunks; /* current # of live chunks */ + u32 nr_max_chunks; /* max # of live chunks */ + size_t min_alloc_size; /* min allocaiton size */ + size_t max_alloc_size; /* max allocation size */ +}; + +extern struct percpu_stats pcpu_stats; +extern struct pcpu_alloc_info pcpu_stats_ai; + +/* + * For debug purposes. We don't care about the flexible array. + */ +static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai) +{ + memcpy(&pcpu_stats_ai, ai, sizeof(struct pcpu_alloc_info)); + + /* initialize min_alloc_size to unit_size */ + pcpu_stats.min_alloc_size = pcpu_stats_ai.unit_size; +} + +/* + * pcpu_stats_area_alloc - increment area allocation stats + * @chunk: the location of the area being allocated + * @size: size of area to allocate in bytes + * + * CONTEXT: + * pcpu_lock. + */ +static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size) +{ + lockdep_assert_held(&pcpu_lock); + + pcpu_stats.nr_alloc++; + pcpu_stats.nr_cur_alloc++; + pcpu_stats.nr_max_alloc = + max(pcpu_stats.nr_max_alloc, pcpu_stats.nr_cur_alloc); + pcpu_stats.min_alloc_size = + min(pcpu_stats.min_alloc_size, size); + pcpu_stats.max_alloc_size = + max(pcpu_stats.max_alloc_size, size); + + chunk->nr_alloc++; + chunk->max_alloc_size = max(chunk->max_alloc_size, size); +} + +/* + * pcpu_stats_area_dealloc - decrement allocation stats + * @chunk: the location of the area being deallocated + * + * CONTEXT: + * pcpu_lock. + */ +static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk) +{ + lockdep_assert_held(&pcpu_lock); + + pcpu_stats.nr_dealloc++; + pcpu_stats.nr_cur_alloc--; + + chunk->nr_alloc--; +} + +/* + * pcpu_stats_chunk_alloc - increment chunk stats + */ +static inline void pcpu_stats_chunk_alloc(void) +{ + unsigned long flags; + spin_lock_irqsave(&pcpu_lock, flags); + + pcpu_stats.nr_chunks++; + pcpu_stats.nr_max_chunks = + max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks); + + spin_unlock_irqrestore(&pcpu_lock, flags); +} + +/* + * pcpu_stats_chunk_dealloc - decrement chunk stats + */ +static inline void pcpu_stats_chunk_dealloc(void) +{ + unsigned long flags; + spin_lock_irqsave(&pcpu_lock, flags); + + pcpu_stats.nr_chunks--; + + spin_unlock_irqrestore(&pcpu_lock, flags); +} + +#else + +static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai) +{ +} + +static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size) +{ +} + +static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk) +{ +} + +static inline void pcpu_stats_chunk_alloc(void) +{ +} + +static inline void pcpu_stats_chunk_dealloc(void) +{ +} + +#endif /* !CONFIG_PERCPU_STATS */ + +#endif |