diff options
Diffstat (limited to 'mm/percpu.c')
| -rw-r--r-- | mm/percpu.c | 1581 |
1 files changed, 1083 insertions, 498 deletions
diff --git a/mm/percpu.c b/mm/percpu.c index db86282fd024..81462ce5866e 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * mm/percpu.c - percpu memory allocator * @@ -5,9 +6,7 @@ * Copyright (C) 2009 Tejun Heo <tj@kernel.org> * * Copyright (C) 2017 Facebook Inc. - * Copyright (C) 2017 Dennis Zhou <dennisszhou@gmail.com> - * - * This file is released under the GPLv2 license. + * Copyright (C) 2017 Dennis Zhou <dennis@kernel.org> * * The percpu allocator handles both static and dynamic areas. Percpu * areas are allocated in chunks which are divided into units. There is @@ -38,9 +37,14 @@ * takes care of normal allocations. * * The allocator organizes chunks into lists according to free size and - * tries to allocate from the fullest chunk first. Each chunk is managed - * by a bitmap with metadata blocks. The allocation map is updated on - * every allocation and free to reflect the current state while the boundary + * memcg-awareness. To make a percpu allocation memcg-aware the __GFP_ACCOUNT + * flag should be passed. All memcg-aware allocations are sharing one set + * of chunks and all unaccounted allocations and allocations performed + * by processes belonging to the root memory cgroup are using the second set. + * + * The allocator tries to allocate from the fullest chunk first. Each chunk + * is managed by a bitmap with metadata blocks. The allocation map is updated + * on every allocation and free to reflect the current state while the boundary * map is only updated on allocation. Each metadata block contains * information to help mitigate the need to iterate over large portions * of the bitmap. The reverse mapping from page to chunk is stored in @@ -65,9 +69,9 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/bitmap.h> +#include <linux/cpumask.h> #include <linux/memblock.h> #include <linux/err.h> -#include <linux/lcm.h> #include <linux/list.h> #include <linux/log2.h> #include <linux/mm.h> @@ -81,6 +85,8 @@ #include <linux/workqueue.h> #include <linux/kmemleak.h> #include <linux/sched.h> +#include <linux/sched/mm.h> +#include <linux/memcontrol.h> #include <asm/cacheflush.h> #include <asm/sections.h> @@ -92,8 +98,13 @@ #include "percpu-internal.h" -/* the slots are sorted by free bytes left, 1-31 bytes share the same slot */ +/* + * The slots are sorted by the size of the biggest continuous free area. + * 1-31 bytes share the same slot. + */ #define PCPU_SLOT_BASE_SHIFT 5 +/* chunks in slots below this are subject to being sidelined on failed alloc */ +#define PCPU_SLOT_FAIL_THRESHOLD 3 #define PCPU_EMPTY_POP_PAGES_LOW 2 #define PCPU_EMPTY_POP_PAGES_HIGH 4 @@ -123,6 +134,9 @@ static int pcpu_unit_size __ro_after_init; static int pcpu_nr_units __ro_after_init; static int pcpu_atom_size __ro_after_init; int pcpu_nr_slots __ro_after_init; +static int pcpu_free_slot __ro_after_init; +int pcpu_sidelined_slot __ro_after_init; +int pcpu_to_depopulate_slot __ro_after_init; static size_t pcpu_chunk_struct_size __ro_after_init; /* cpus with the lowest and highest unit addresses */ @@ -131,7 +145,6 @@ static unsigned int pcpu_high_unit_cpu __ro_after_init; /* the address of the first chunk which starts with the kernel static area */ void *pcpu_base_addr __ro_after_init; -EXPORT_SYMBOL_GPL(pcpu_base_addr); static const int *pcpu_unit_map __ro_after_init; /* cpu -> unit */ const unsigned long *pcpu_unit_offsets __ro_after_init; /* cpu -> unit offset */ @@ -158,14 +171,11 @@ struct pcpu_chunk *pcpu_reserved_chunk __ro_after_init; DEFINE_SPINLOCK(pcpu_lock); /* all internal data structures */ static DEFINE_MUTEX(pcpu_alloc_mutex); /* chunk create/destroy, [de]pop, map ext */ -struct list_head *pcpu_slot __ro_after_init; /* chunk list slots */ - -/* chunks which need their map areas extended, protected by pcpu_lock */ -static LIST_HEAD(pcpu_map_extend_chunks); +struct list_head *pcpu_chunk_lists __ro_after_init; /* chunk list slots */ /* - * The number of empty populated pages, protected by pcpu_lock. The - * reserved chunk doesn't contribute to the count. + * The number of empty populated pages, protected by pcpu_lock. + * The reserved chunk doesn't contribute to the count. */ int pcpu_nr_empty_pop_pages; @@ -225,28 +235,31 @@ static int __pcpu_size_to_slot(int size) static int pcpu_size_to_slot(int size) { if (size == pcpu_unit_size) - return pcpu_nr_slots - 1; + return pcpu_free_slot; return __pcpu_size_to_slot(size); } static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) { - if (chunk->free_bytes < PCPU_MIN_ALLOC_SIZE || chunk->contig_bits == 0) + const struct pcpu_block_md *chunk_md = &chunk->chunk_md; + + if (chunk->free_bytes < PCPU_MIN_ALLOC_SIZE || + chunk_md->contig_hint == 0) return 0; - return pcpu_size_to_slot(chunk->free_bytes); + return pcpu_size_to_slot(chunk_md->contig_hint * PCPU_MIN_ALLOC_SIZE); } /* set the pointer to a chunk in a page struct */ static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu) { - page->index = (unsigned long)pcpu; + page->private = (unsigned long)pcpu; } /* obtain pointer to a chunk from a page struct */ static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page) { - return (struct pcpu_chunk *)page->index; + return (struct pcpu_chunk *)page->private; } static int __maybe_unused pcpu_page_idx(unsigned int cpu, int page_idx) @@ -266,33 +279,6 @@ static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, pcpu_unit_page_offset(cpu, page_idx); } -static void pcpu_next_unpop(unsigned long *bitmap, int *rs, int *re, int end) -{ - *rs = find_next_zero_bit(bitmap, end, *rs); - *re = find_next_bit(bitmap, end, *rs + 1); -} - -static void pcpu_next_pop(unsigned long *bitmap, int *rs, int *re, int end) -{ - *rs = find_next_bit(bitmap, end, *rs); - *re = find_next_zero_bit(bitmap, end, *rs + 1); -} - -/* - * Bitmap region iterators. Iterates over the bitmap between - * [@start, @end) in @chunk. @rs and @re should be integer variables - * and will be set to start and end index of the current free region. - */ -#define pcpu_for_each_unpop_region(bitmap, rs, re, start, end) \ - for ((rs) = (start), pcpu_next_unpop((bitmap), &(rs), &(re), (end)); \ - (rs) < (re); \ - (rs) = (re) + 1, pcpu_next_unpop((bitmap), &(rs), &(re), (end))) - -#define pcpu_for_each_pop_region(bitmap, rs, re, start, end) \ - for ((rs) = (start), pcpu_next_pop((bitmap), &(rs), &(re), (end)); \ - (rs) < (re); \ - (rs) = (re) + 1, pcpu_next_pop((bitmap), &(rs), &(re), (end))) - /* * The following are helper functions to help access bitmaps and convert * between bitmap offsets to address offsets. @@ -319,6 +305,53 @@ static unsigned long pcpu_block_off_to_off(int index, int off) } /** + * pcpu_check_block_hint - check against the contig hint + * @block: block of interest + * @bits: size of allocation + * @align: alignment of area (max PAGE_SIZE) + * + * Check to see if the allocation can fit in the block's contig hint. + * Note, a chunk uses the same hints as a block so this can also check against + * the chunk's contig hint. + */ +static bool pcpu_check_block_hint(struct pcpu_block_md *block, int bits, + size_t align) +{ + int bit_off = ALIGN(block->contig_hint_start, align) - + block->contig_hint_start; + + return bit_off + bits <= block->contig_hint; +} + +/* + * 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 + * first fit. However, if we know a scan_hint at position scan_hint_start + * cannot fulfill an allocation, we can begin scanning from there knowing + * the contig_hint will be our fallback. + */ +static int pcpu_next_hint(struct pcpu_block_md *block, int alloc_bits) +{ + /* + * The three conditions below determine if we can skip past the + * scan_hint. First, does the scan hint exist. Second, is the + * contig_hint after the scan_hint (possibly not true iff + * contig_hint == scan_hint). Third, is the allocation request + * larger than the scan_hint. + */ + if (block->scan_hint && + block->contig_hint_start > block->scan_hint_start && + alloc_bits > block->scan_hint) + return block->scan_hint_start + block->scan_hint; + + return block->first_free; +} + +/** * pcpu_next_md_free_region - finds the next hint free area * @chunk: chunk of interest * @bit_off: chunk offset @@ -413,9 +446,11 @@ static void pcpu_next_fit_region(struct pcpu_chunk *chunk, int alloc_bits, if (block->contig_hint && block->contig_hint_start >= block_off && block->contig_hint >= *bits + alloc_bits) { + int start = pcpu_next_hint(block, alloc_bits); + *bits += alloc_bits + block->contig_hint_start - - block->first_free; - *bit_off = pcpu_block_off_to_off(i, block->first_free); + start; + *bit_off = pcpu_block_off_to_off(i, start); return; } /* reset to satisfy the second predicate above */ @@ -474,7 +509,7 @@ static void *pcpu_mem_zalloc(size_t size, gfp_t gfp) if (size <= PAGE_SIZE) return kzalloc(size, gfp); else - return __vmalloc(size, gfp | __GFP_ZERO, PAGE_KERNEL); + return __vmalloc(size, gfp | __GFP_ZERO); } /** @@ -488,6 +523,22 @@ static void pcpu_mem_free(void *ptr) kvfree(ptr); } +static void __pcpu_chunk_move(struct pcpu_chunk *chunk, int slot, + bool move_front) +{ + if (chunk != pcpu_reserved_chunk) { + if (move_front) + list_move(&chunk->list, &pcpu_chunk_lists[slot]); + else + list_move_tail(&chunk->list, &pcpu_chunk_lists[slot]); + } +} + +static void pcpu_chunk_move(struct pcpu_chunk *chunk, int slot) +{ + __pcpu_chunk_move(chunk, slot, true); +} + /** * pcpu_chunk_relocate - put chunk in the appropriate chunk slot * @chunk: chunk of interest @@ -505,110 +556,65 @@ static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) { int nslot = pcpu_chunk_slot(chunk); - if (chunk != pcpu_reserved_chunk && oslot != nslot) { - if (oslot < nslot) - list_move(&chunk->list, &pcpu_slot[nslot]); - else - list_move_tail(&chunk->list, &pcpu_slot[nslot]); - } + /* leave isolated chunks in-place */ + if (chunk->isolated) + return; + + if (oslot != nslot) + __pcpu_chunk_move(chunk, nslot, oslot < nslot); } -/** - * pcpu_cnt_pop_pages- counts populated backing pages in range - * @chunk: chunk of interest - * @bit_off: start offset - * @bits: size of area to check - * - * Calculates the number of populated pages in the region - * [page_start, page_end). This keeps track of how many empty populated - * pages are available and decide if async work should be scheduled. - * - * RETURNS: - * The nr of populated pages. - */ -static inline int pcpu_cnt_pop_pages(struct pcpu_chunk *chunk, int bit_off, - int bits) +static void pcpu_isolate_chunk(struct pcpu_chunk *chunk) { - int page_start = PFN_UP(bit_off * PCPU_MIN_ALLOC_SIZE); - int page_end = PFN_DOWN((bit_off + bits) * PCPU_MIN_ALLOC_SIZE); - - if (page_start >= page_end) - return 0; + lockdep_assert_held(&pcpu_lock); - /* - * bitmap_weight counts the number of bits set in a bitmap up to - * the specified number of bits. This is counting the populated - * pages up to page_end and then subtracting the populated pages - * up to page_start to count the populated pages in - * [page_start, page_end). - */ - return bitmap_weight(chunk->populated, page_end) - - bitmap_weight(chunk->populated, page_start); + if (!chunk->isolated) { + chunk->isolated = true; + pcpu_nr_empty_pop_pages -= chunk->nr_empty_pop_pages; + } + list_move(&chunk->list, &pcpu_chunk_lists[pcpu_to_depopulate_slot]); } -/** - * pcpu_chunk_update - updates the chunk metadata given a free area - * @chunk: chunk of interest - * @bit_off: chunk offset - * @bits: size of free area - * - * This updates the chunk's contig hint and starting offset given a free area. - * Choose the best starting offset if the contig hint is equal. - */ -static void pcpu_chunk_update(struct pcpu_chunk *chunk, int bit_off, int bits) -{ - if (bits > chunk->contig_bits) { - chunk->contig_bits_start = bit_off; - chunk->contig_bits = bits; - } else if (bits == chunk->contig_bits && chunk->contig_bits_start && - (!bit_off || - __ffs(bit_off) > __ffs(chunk->contig_bits_start))) { - /* use the start with the best alignment */ - chunk->contig_bits_start = bit_off; +static void pcpu_reintegrate_chunk(struct pcpu_chunk *chunk) +{ + lockdep_assert_held(&pcpu_lock); + + if (chunk->isolated) { + chunk->isolated = false; + pcpu_nr_empty_pop_pages += chunk->nr_empty_pop_pages; + pcpu_chunk_relocate(chunk, -1); } } -/** - * pcpu_chunk_refresh_hint - updates metadata about a chunk +/* + * pcpu_update_empty_pages - update empty page counters * @chunk: chunk of interest + * @nr: nr of empty pages * - * Iterates over the metadata blocks to find the largest contig area. - * It also counts the populated pages and uses the delta to update the - * global count. - * - * Updates: - * chunk->contig_bits - * chunk->contig_bits_start - * nr_empty_pop_pages (chunk and global) + * This is used to keep track of the empty pages now based on the premise + * a md_block covers a page. The hint update functions recognize if a block + * is made full or broken to calculate deltas for keeping track of free pages. */ -static void pcpu_chunk_refresh_hint(struct pcpu_chunk *chunk) +static inline void pcpu_update_empty_pages(struct pcpu_chunk *chunk, int nr) { - int bit_off, bits, nr_empty_pop_pages; - - /* clear metadata */ - chunk->contig_bits = 0; - - bit_off = chunk->first_bit; - bits = nr_empty_pop_pages = 0; - pcpu_for_each_md_free_region(chunk, bit_off, bits) { - pcpu_chunk_update(chunk, bit_off, bits); - - nr_empty_pop_pages += pcpu_cnt_pop_pages(chunk, bit_off, bits); - } - - /* - * Keep track of nr_empty_pop_pages. - * - * The chunk maintains the previous number of free pages it held, - * so the delta is used to update the global counter. The reserved - * chunk is not part of the free page count as they are populated - * at init and are special to serving reserved allocations. - */ - if (chunk != pcpu_reserved_chunk) - pcpu_nr_empty_pop_pages += - (nr_empty_pop_pages - chunk->nr_empty_pop_pages); + chunk->nr_empty_pop_pages += nr; + if (chunk != pcpu_reserved_chunk && !chunk->isolated) + pcpu_nr_empty_pop_pages += nr; +} - chunk->nr_empty_pop_pages = nr_empty_pop_pages; +/* + * pcpu_region_overlap - determines if two regions overlap + * @a: start of first region, inclusive + * @b: end of first region, exclusive + * @x: start of second region, inclusive + * @y: end of second region, exclusive + * + * This is used to determine if the hint region [a, b) overlaps with the + * allocated region [x, y). + */ +static inline bool pcpu_region_overlap(int a, int b, int x, int y) +{ + return (a < y) && (x < b); } /** @@ -629,19 +635,134 @@ static void pcpu_block_update(struct pcpu_block_md *block, int start, int end) if (start == 0) block->left_free = contig; - if (end == PCPU_BITMAP_BLOCK_BITS) + if (end == block->nr_bits) block->right_free = contig; if (contig > block->contig_hint) { + /* promote the old contig_hint to be the new scan_hint */ + if (start > block->contig_hint_start) { + if (block->contig_hint > block->scan_hint) { + block->scan_hint_start = + block->contig_hint_start; + block->scan_hint = block->contig_hint; + } else if (start < block->scan_hint_start) { + /* + * The old contig_hint == scan_hint. But, the + * new contig is larger so hold the invariant + * scan_hint_start < contig_hint_start. + */ + block->scan_hint = 0; + } + } else { + block->scan_hint = 0; + } block->contig_hint_start = start; block->contig_hint = contig; - } else if (block->contig_hint_start && contig == block->contig_hint && - (!start || __ffs(start) > __ffs(block->contig_hint_start))) { - /* use the start with the best alignment */ - block->contig_hint_start = start; + } else if (contig == block->contig_hint) { + if (block->contig_hint_start && + (!start || + __ffs(start) > __ffs(block->contig_hint_start))) { + /* start has a better alignment so use it */ + block->contig_hint_start = start; + if (start < block->scan_hint_start && + block->contig_hint > block->scan_hint) + block->scan_hint = 0; + } else if (start > block->scan_hint_start || + block->contig_hint > block->scan_hint) { + /* + * Knowing contig == contig_hint, update the scan_hint + * if it is farther than or larger than the current + * scan_hint. + */ + block->scan_hint_start = start; + block->scan_hint = contig; + } + } else { + /* + * The region is smaller than the contig_hint. So only update + * the scan_hint if it is larger than or equal and farther than + * the current scan_hint. + */ + if ((start < block->contig_hint_start && + (contig > block->scan_hint || + (contig == block->scan_hint && + start > block->scan_hint_start)))) { + block->scan_hint_start = start; + block->scan_hint = contig; + } } } +/* + * pcpu_block_update_scan - update a block given a free area from a scan + * @chunk: chunk of interest + * @bit_off: chunk offset + * @bits: size of free area + * + * Finding the final allocation spot first goes through pcpu_find_block_fit() + * to find a block that can hold the allocation and then pcpu_alloc_area() + * where a scan is used. When allocations require specific alignments, + * we can inadvertently create holes which will not be seen in the alloc + * or free paths. + * + * This takes a given free area hole and updates a block as it may change the + * scan_hint. We need to scan backwards to ensure we don't miss free bits + * from alignment. + */ +static void pcpu_block_update_scan(struct pcpu_chunk *chunk, int bit_off, + int bits) +{ + int s_off = pcpu_off_to_block_off(bit_off); + int e_off = s_off + bits; + int s_index, l_bit; + struct pcpu_block_md *block; + + if (e_off > PCPU_BITMAP_BLOCK_BITS) + return; + + s_index = pcpu_off_to_block_index(bit_off); + block = chunk->md_blocks + s_index; + + /* scan backwards in case of alignment skipping free bits */ + l_bit = find_last_bit(pcpu_index_alloc_map(chunk, s_index), s_off); + s_off = (s_off == l_bit) ? 0 : l_bit + 1; + + pcpu_block_update(block, s_off, e_off); +} + +/** + * pcpu_chunk_refresh_hint - updates metadata about a chunk + * @chunk: chunk of interest + * @full_scan: if we should scan from the beginning + * + * Iterates over the metadata blocks to find the largest contig area. + * A full scan can be avoided on the allocation path as this is triggered + * if we broke the contig_hint. In doing so, the scan_hint will be before + * the contig_hint or after if the scan_hint == contig_hint. This cannot + * be prevented on freeing as we want to find the largest area possibly + * spanning blocks. + */ +static void pcpu_chunk_refresh_hint(struct pcpu_chunk *chunk, bool full_scan) +{ + struct pcpu_block_md *chunk_md = &chunk->chunk_md; + int bit_off, bits; + + /* promote scan_hint to contig_hint */ + if (!full_scan && chunk_md->scan_hint) { + bit_off = chunk_md->scan_hint_start + chunk_md->scan_hint; + chunk_md->contig_hint_start = chunk_md->scan_hint_start; + chunk_md->contig_hint = chunk_md->scan_hint; + chunk_md->scan_hint = 0; + } else { + bit_off = chunk_md->first_free; + chunk_md->contig_hint = 0; + } + + bits = 0; + pcpu_for_each_md_free_region(chunk, bit_off, bits) + pcpu_block_update(chunk_md, bit_off, bit_off + bits); +} + /** * pcpu_block_refresh_hint * @chunk: chunk of interest @@ -654,17 +775,24 @@ static void pcpu_block_refresh_hint(struct pcpu_chunk *chunk, int index) { struct pcpu_block_md *block = chunk->md_blocks + index; unsigned long *alloc_map = pcpu_index_alloc_map(chunk, index); - int rs, re; /* region start, region end */ + unsigned int start, end; /* region start, region end */ + + /* promote scan_hint to contig_hint */ + if (block->scan_hint) { + start = block->scan_hint_start + block->scan_hint; + block->contig_hint_start = block->scan_hint_start; + block->contig_hint = block->scan_hint; + block->scan_hint = 0; + } else { + start = block->first_free; + block->contig_hint = 0; + } - /* clear hints */ - block->contig_hint = 0; - block->left_free = block->right_free = 0; + block->right_free = 0; /* iterate over free areas and update the contig hints */ - pcpu_for_each_unpop_region(alloc_map, rs, re, block->first_free, - PCPU_BITMAP_BLOCK_BITS) { - pcpu_block_update(block, rs, re); - } + for_each_clear_bitrange_from(start, end, alloc_map, PCPU_BITMAP_BLOCK_BITS) + pcpu_block_update(block, start, end); } /** @@ -680,6 +808,8 @@ static void pcpu_block_refresh_hint(struct pcpu_chunk *chunk, int index) static void pcpu_block_update_hint_alloc(struct pcpu_chunk *chunk, int bit_off, int bits) { + struct pcpu_block_md *chunk_md = &chunk->chunk_md; + int nr_empty_pages = 0; struct pcpu_block_md *s_block, *e_block, *block; int s_index, e_index; /* block indexes of the freed allocation */ int s_off, e_off; /* block offsets of the freed allocation */ @@ -700,6 +830,11 @@ static void pcpu_block_update_hint_alloc(struct pcpu_chunk *chunk, int bit_off, /* * Update s_block. + */ + if (s_block->contig_hint == PCPU_BITMAP_BLOCK_BITS) + nr_empty_pages++; + + /* * block->first_free must be updated if the allocation takes its place. * If the allocation breaks the contig_hint, a scan is required to * restore this hint. @@ -710,9 +845,20 @@ static void pcpu_block_update_hint_alloc(struct pcpu_chunk *chunk, int bit_off, PCPU_BITMAP_BLOCK_BITS, s_off + bits); - if (s_off >= s_block->contig_hint_start && - s_off < s_block->contig_hint_start + s_block->contig_hint) { + if (pcpu_region_overlap(s_block->scan_hint_start, + s_block->scan_hint_start + s_block->scan_hint, + s_off, + s_off + bits)) + s_block->scan_hint = 0; + + if (pcpu_region_overlap(s_block->contig_hint_start, + s_block->contig_hint_start + + s_block->contig_hint, + s_off, + s_off + bits)) { /* block contig hint is broken - scan to fix it */ + if (!s_off) + s_block->left_free = 0; pcpu_block_refresh_hint(chunk, s_index); } else { /* update left and right contig manually */ @@ -728,6 +874,9 @@ static void pcpu_block_update_hint_alloc(struct pcpu_chunk *chunk, int bit_off, * Update e_block. */ if (s_index != e_index) { + if (e_block->contig_hint == PCPU_BITMAP_BLOCK_BITS) + nr_empty_pages++; + /* * When the allocation is across blocks, the end is along * the left part of the e_block. @@ -740,11 +889,14 @@ static void pcpu_block_update_hint_alloc(struct pcpu_chunk *chunk, int bit_off, /* reset the block */ e_block++; } else { + if (e_off > e_block->scan_hint_start) + e_block->scan_hint = 0; + + e_block->left_free = 0; if (e_off > e_block->contig_hint_start) { /* contig hint is broken - scan to fix it */ pcpu_block_refresh_hint(chunk, e_index); } else { - e_block->left_free = 0; e_block->right_free = min_t(int, e_block->right_free, PCPU_BITMAP_BLOCK_BITS - e_off); @@ -752,7 +904,9 @@ static void pcpu_block_update_hint_alloc(struct pcpu_chunk *chunk, int bit_off, } /* update in-between md_blocks */ + nr_empty_pages += (e_index - s_index - 1); for (block = s_block + 1; block < e_block; block++) { + block->scan_hint = 0; block->contig_hint = 0; block->left_free = 0; block->right_free = 0; @@ -760,13 +914,32 @@ static void pcpu_block_update_hint_alloc(struct pcpu_chunk *chunk, int bit_off, } /* + * If the allocation is not atomic, some blocks may not be + * populated with pages, while we account it here. The number + * of pages will be added back with pcpu_chunk_populated() + * when populating pages. + */ + if (nr_empty_pages) + pcpu_update_empty_pages(chunk, -nr_empty_pages); + + if (pcpu_region_overlap(chunk_md->scan_hint_start, + chunk_md->scan_hint_start + + chunk_md->scan_hint, + bit_off, + bit_off + bits)) + chunk_md->scan_hint = 0; + + /* * The only time a full chunk scan is required is if the chunk * contig hint is broken. Otherwise, it means a smaller space * was used and therefore the chunk contig hint is still correct. */ - if (bit_off >= chunk->contig_bits_start && - bit_off < chunk->contig_bits_start + chunk->contig_bits) - pcpu_chunk_refresh_hint(chunk); + if (pcpu_region_overlap(chunk_md->contig_hint_start, + chunk_md->contig_hint_start + + chunk_md->contig_hint, + bit_off, + bit_off + bits)) + pcpu_chunk_refresh_hint(chunk, false); } /** @@ -782,13 +955,15 @@ static void pcpu_block_update_hint_alloc(struct pcpu_chunk *chunk, int bit_off, * * A chunk update is triggered if a page becomes free, a block becomes free, * or the free spans across blocks. This tradeoff is to minimize iterating - * over the block metadata to update chunk->contig_bits. chunk->contig_bits - * may be off by up to a page, but it will never be more than the available - * space. If the contig hint is contained in one block, it will be accurate. + * over the block metadata to update chunk_md->contig_hint. + * chunk_md->contig_hint may be off by up to a page, but it will never be more + * than the available space. If the contig hint is contained in one block, it + * will be accurate. */ static void pcpu_block_update_hint_free(struct pcpu_chunk *chunk, int bit_off, int bits) { + int nr_empty_pages = 0; struct pcpu_block_md *s_block, *e_block, *block; int s_index, e_index; /* block indexes of the freed allocation */ int s_off, e_off; /* block offsets of the freed allocation */ @@ -842,16 +1017,22 @@ static void pcpu_block_update_hint_free(struct pcpu_chunk *chunk, int bit_off, /* update s_block */ e_off = (s_index == e_index) ? end : PCPU_BITMAP_BLOCK_BITS; + if (!start && e_off == PCPU_BITMAP_BLOCK_BITS) + nr_empty_pages++; pcpu_block_update(s_block, start, e_off); /* freeing in the same block */ if (s_index != e_index) { /* update e_block */ + if (end == PCPU_BITMAP_BLOCK_BITS) + nr_empty_pages++; pcpu_block_update(e_block, 0, end); /* reset md_blocks in the middle */ + nr_empty_pages += (e_index - s_index - 1); for (block = s_block + 1; block < e_block; block++) { block->first_free = 0; + block->scan_hint = 0; block->contig_hint_start = 0; block->contig_hint = PCPU_BITMAP_BLOCK_BITS; block->left_free = PCPU_BITMAP_BLOCK_BITS; @@ -859,19 +1040,21 @@ static void pcpu_block_update_hint_free(struct pcpu_chunk *chunk, int bit_off, } } + if (nr_empty_pages) + pcpu_update_empty_pages(chunk, nr_empty_pages); + /* - * Refresh chunk metadata when the free makes a page free, a block - * free, or spans across blocks. The contig hint may be off by up to - * a page, but if the hint is contained in a block, it will be accurate - * with the else condition below. + * Refresh chunk metadata when the free makes a block free or spans + * across blocks. The contig_hint may be off by up to a page, but if + * the contig_hint is contained in a block, it will be accurate with + * the else condition below. */ - if ((ALIGN_DOWN(end, min(PCPU_BITS_PER_PAGE, PCPU_BITMAP_BLOCK_BITS)) > - ALIGN(start, min(PCPU_BITS_PER_PAGE, PCPU_BITMAP_BLOCK_BITS))) || - s_index != e_index) - pcpu_chunk_refresh_hint(chunk); + if (((end - start) >= PCPU_BITMAP_BLOCK_BITS) || s_index != e_index) + pcpu_chunk_refresh_hint(chunk, true); else - pcpu_chunk_update(chunk, pcpu_block_off_to_off(s_index, start), - s_block->contig_hint); + pcpu_block_update(&chunk->chunk_md, + pcpu_block_off_to_off(s_index, start), + end); } /** @@ -890,17 +1073,18 @@ static void pcpu_block_update_hint_free(struct pcpu_chunk *chunk, int bit_off, static bool pcpu_is_populated(struct pcpu_chunk *chunk, int bit_off, int bits, int *next_off) { - int page_start, page_end, rs, re; + unsigned int start, end; - page_start = PFN_DOWN(bit_off * PCPU_MIN_ALLOC_SIZE); - page_end = PFN_UP((bit_off + bits) * PCPU_MIN_ALLOC_SIZE); + start = PFN_DOWN(bit_off * PCPU_MIN_ALLOC_SIZE); + end = PFN_UP((bit_off + bits) * PCPU_MIN_ALLOC_SIZE); - rs = page_start; - pcpu_next_unpop(chunk->populated, &rs, &re, page_end); - if (rs >= page_end) + start = find_next_zero_bit(chunk->populated, end, start); + if (start >= end) return true; - *next_off = re * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE; + end = find_next_bit(chunk->populated, end, start + 1); + + *next_off = end * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE; return false; } @@ -926,20 +1110,18 @@ static bool pcpu_is_populated(struct pcpu_chunk *chunk, int bit_off, int bits, static int pcpu_find_block_fit(struct pcpu_chunk *chunk, int alloc_bits, size_t align, bool pop_only) { + struct pcpu_block_md *chunk_md = &chunk->chunk_md; int bit_off, bits, next_off; /* - * Check to see if the allocation can fit in the chunk's contig hint. - * This is an optimization to prevent scanning by assuming if it - * cannot fit in the global hint, there is memory pressure and creating - * a new chunk would happen soon. + * This is an optimization to prevent scanning by assuming if the + * allocation cannot fit in the global hint, there is memory pressure + * and creating a new chunk would happen soon. */ - bit_off = ALIGN(chunk->contig_bits_start, align) - - chunk->contig_bits_start; - if (bit_off + alloc_bits > chunk->contig_bits) + if (!pcpu_check_block_hint(chunk_md, alloc_bits, align)) return -1; - bit_off = chunk->first_bit; + bit_off = pcpu_next_hint(chunk_md, alloc_bits); bits = 0; pcpu_for_each_fit_region(chunk, alloc_bits, align, bit_off, bits) { if (!pop_only || pcpu_is_populated(chunk, bit_off, bits, @@ -956,6 +1138,62 @@ static int pcpu_find_block_fit(struct pcpu_chunk *chunk, int alloc_bits, return bit_off; } +/* + * pcpu_find_zero_area - modified from bitmap_find_next_zero_area_off() + * @map: the address to base the search on + * @size: the bitmap size in bits + * @start: the bitnumber to start searching at + * @nr: the number of zeroed bits we're looking for + * @align_mask: alignment mask for zero area + * @largest_off: offset of the largest area skipped + * @largest_bits: size of the largest area skipped + * + * The @align_mask should be one less than a power of 2. + * + * This is a modified version of bitmap_find_next_zero_area_off() to remember + * the largest area that was skipped. This is imperfect, but in general is + * good enough. The largest remembered region is the largest failed region + * seen. This does not include anything we possibly skipped due to alignment. + * pcpu_block_update_scan() does scan backwards to try and recover what was + * lost to alignment. While this can cause scanning to miss earlier possible + * free areas, smaller allocations will eventually fill those holes. + */ +static unsigned long pcpu_find_zero_area(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned long nr, + unsigned long align_mask, + unsigned long *largest_off, + unsigned long *largest_bits) +{ + unsigned long index, end, i, area_off, area_bits; +again: + index = find_next_zero_bit(map, size, start); + + /* Align allocation */ + index = __ALIGN_MASK(index, align_mask); + area_off = index; + + end = index + nr; + if (end > size) + return end; + i = find_next_bit(map, end, index); + if (i < end) { + area_bits = i - area_off; + /* remember largest unused area with best alignment */ + if (area_bits > *largest_bits || + (area_bits == *largest_bits && *largest_off && + (!area_off || __ffs(area_off) > __ffs(*largest_off)))) { + *largest_off = area_off; + *largest_bits = area_bits; + } + + start = i + 1; + goto again; + } + return index; +} + /** * pcpu_alloc_area - allocates an area from a pcpu_chunk * @chunk: chunk of interest @@ -978,7 +1216,9 @@ static int pcpu_find_block_fit(struct pcpu_chunk *chunk, int alloc_bits, static int pcpu_alloc_area(struct pcpu_chunk *chunk, int alloc_bits, size_t align, int start) { + struct pcpu_block_md *chunk_md = &chunk->chunk_md; size_t align_mask = (align) ? (align - 1) : 0; + unsigned long area_off = 0, area_bits = 0; int bit_off, end, oslot; lockdep_assert_held(&pcpu_lock); @@ -988,12 +1228,16 @@ static int pcpu_alloc_area(struct pcpu_chunk *chunk, int alloc_bits, /* * Search to find a fit. */ - end = start + alloc_bits + PCPU_BITMAP_BLOCK_BITS; - bit_off = bitmap_find_next_zero_area(chunk->alloc_map, end, start, - alloc_bits, align_mask); + end = min_t(int, start + alloc_bits + PCPU_BITMAP_BLOCK_BITS, + pcpu_chunk_map_bits(chunk)); + bit_off = pcpu_find_zero_area(chunk->alloc_map, end, start, alloc_bits, + align_mask, &area_off, &area_bits); if (bit_off >= end) return -1; + if (area_bits) + pcpu_block_update_scan(chunk, area_off, area_bits); + /* update alloc map */ bitmap_set(chunk->alloc_map, bit_off, alloc_bits); @@ -1005,8 +1249,8 @@ static int pcpu_alloc_area(struct pcpu_chunk *chunk, int alloc_bits, chunk->free_bytes -= alloc_bits * PCPU_MIN_ALLOC_SIZE; /* update first free bit */ - if (bit_off == chunk->first_bit) - chunk->first_bit = find_next_zero_bit( + if (bit_off == chunk_md->first_free) + chunk_md->first_free = find_next_zero_bit( chunk->alloc_map, pcpu_chunk_map_bits(chunk), bit_off + alloc_bits); @@ -1025,10 +1269,14 @@ static int pcpu_alloc_area(struct pcpu_chunk *chunk, int alloc_bits, * * This function determines the size of an allocation to free using * the boundary bitmap and clears the allocation map. + * + * RETURNS: + * Number of freed bytes. */ -static void pcpu_free_area(struct pcpu_chunk *chunk, int off) +static int pcpu_free_area(struct pcpu_chunk *chunk, int off) { - int bit_off, bits, end, oslot; + struct pcpu_block_md *chunk_md = &chunk->chunk_md; + int bit_off, bits, end, oslot, freed; lockdep_assert_held(&pcpu_lock); pcpu_stats_area_dealloc(chunk); @@ -1043,28 +1291,42 @@ static void pcpu_free_area(struct pcpu_chunk *chunk, int off) bits = end - bit_off; bitmap_clear(chunk->alloc_map, bit_off, bits); + freed = bits * PCPU_MIN_ALLOC_SIZE; + /* update metadata */ - chunk->free_bytes += bits * PCPU_MIN_ALLOC_SIZE; + chunk->free_bytes += freed; /* update first free bit */ - chunk->first_bit = min(chunk->first_bit, bit_off); + chunk_md->first_free = min(chunk_md->first_free, bit_off); pcpu_block_update_hint_free(chunk, bit_off, bits); pcpu_chunk_relocate(chunk, oslot); + + return freed; +} + +static void pcpu_init_md_block(struct pcpu_block_md *block, int nr_bits) +{ + block->scan_hint = 0; + block->contig_hint = nr_bits; + block->left_free = nr_bits; + block->right_free = nr_bits; + block->first_free = 0; + block->nr_bits = nr_bits; } static void pcpu_init_md_blocks(struct pcpu_chunk *chunk) { struct pcpu_block_md *md_block; + /* init the chunk's block */ + pcpu_init_md_block(&chunk->chunk_md, pcpu_chunk_map_bits(chunk)); + for (md_block = chunk->md_blocks; md_block != chunk->md_blocks + pcpu_chunk_nr_blocks(chunk); - md_block++) { - md_block->contig_hint = PCPU_BITMAP_BLOCK_BITS; - md_block->left_free = PCPU_BITMAP_BLOCK_BITS; - md_block->right_free = PCPU_BITMAP_BLOCK_BITS; - } + md_block++) + pcpu_init_md_block(md_block, PCPU_BITMAP_BLOCK_BITS); } /** @@ -1084,26 +1346,20 @@ static struct pcpu_chunk * __init pcpu_alloc_first_chunk(unsigned long tmp_addr, int map_size) { struct pcpu_chunk *chunk; - unsigned long aligned_addr, lcm_align; + unsigned long aligned_addr; int start_offset, offset_bits, region_size, region_bits; + size_t alloc_size; /* region calculations */ aligned_addr = tmp_addr & PAGE_MASK; start_offset = tmp_addr - aligned_addr; - - /* - * Align the end of the region with the LCM of PAGE_SIZE and - * PCPU_BITMAP_BLOCK_SIZE. One of these constants is a multiple of - * the other. - */ - lcm_align = lcm(PAGE_SIZE, PCPU_BITMAP_BLOCK_SIZE); - region_size = ALIGN(start_offset + map_size, lcm_align); + region_size = ALIGN(start_offset + map_size, PAGE_SIZE); /* allocate chunk */ - chunk = memblock_alloc(sizeof(struct pcpu_chunk) + - BITS_TO_LONGS(region_size >> PAGE_SHIFT), - SMP_CACHE_BYTES); + alloc_size = struct_size(chunk, populated, + BITS_TO_LONGS(region_size >> PAGE_SHIFT)); + chunk = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES); INIT_LIST_HEAD(&chunk->list); @@ -1114,23 +1370,27 @@ static struct pcpu_chunk * __init pcpu_alloc_first_chunk(unsigned long tmp_addr, chunk->nr_pages = region_size >> PAGE_SHIFT; region_bits = pcpu_chunk_map_bits(chunk); - chunk->alloc_map = memblock_alloc(BITS_TO_LONGS(region_bits) * sizeof(chunk->alloc_map[0]), - SMP_CACHE_BYTES); - chunk->bound_map = memblock_alloc(BITS_TO_LONGS(region_bits + 1) * sizeof(chunk->bound_map[0]), - SMP_CACHE_BYTES); - chunk->md_blocks = memblock_alloc(pcpu_chunk_nr_blocks(chunk) * sizeof(chunk->md_blocks[0]), - SMP_CACHE_BYTES); + alloc_size = BITS_TO_LONGS(region_bits) * sizeof(chunk->alloc_map[0]); + chunk->alloc_map = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES); + + alloc_size = + BITS_TO_LONGS(region_bits + 1) * sizeof(chunk->bound_map[0]); + chunk->bound_map = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES); + + alloc_size = pcpu_chunk_nr_blocks(chunk) * sizeof(chunk->md_blocks[0]); + chunk->md_blocks = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES); +#ifdef NEED_PCPUOBJ_EXT + /* first chunk is free to use */ + chunk->obj_exts = NULL; +#endif pcpu_init_md_blocks(chunk); /* manage populated page bitmap */ chunk->immutable = true; bitmap_fill(chunk->populated, chunk->nr_pages); chunk->nr_populated = chunk->nr_pages; - chunk->nr_empty_pop_pages = - pcpu_cnt_pop_pages(chunk, start_offset / PCPU_MIN_ALLOC_SIZE, - map_size / PCPU_MIN_ALLOC_SIZE); + chunk->nr_empty_pop_pages = chunk->nr_pages; - chunk->contig_bits = map_size / PCPU_MIN_ALLOC_SIZE; chunk->free_bytes = map_size; if (chunk->start_offset) { @@ -1140,7 +1400,7 @@ static struct pcpu_chunk * __init pcpu_alloc_first_chunk(unsigned long tmp_addr, set_bit(0, chunk->bound_map); set_bit(offset_bits, chunk->bound_map); - chunk->first_bit = offset_bits; + chunk->chunk_md.first_free = offset_bits; pcpu_block_update_hint_alloc(chunk, 0, offset_bits); } @@ -1190,14 +1450,27 @@ static struct pcpu_chunk *pcpu_alloc_chunk(gfp_t gfp) if (!chunk->md_blocks) goto md_blocks_fail; +#ifdef NEED_PCPUOBJ_EXT + if (need_pcpuobj_ext()) { + chunk->obj_exts = + pcpu_mem_zalloc(pcpu_chunk_map_bits(chunk) * + sizeof(struct pcpuobj_ext), gfp); + if (!chunk->obj_exts) + goto objcg_fail; + } +#endif + pcpu_init_md_blocks(chunk); /* init metadata */ - chunk->contig_bits = region_bits; chunk->free_bytes = chunk->nr_pages * PAGE_SIZE; return chunk; +#ifdef NEED_PCPUOBJ_EXT +objcg_fail: + pcpu_mem_free(chunk->md_blocks); +#endif md_blocks_fail: pcpu_mem_free(chunk->bound_map); bound_map_fail: @@ -1212,6 +1485,9 @@ static void pcpu_free_chunk(struct pcpu_chunk *chunk) { if (!chunk) return; +#ifdef NEED_PCPUOBJ_EXT + pcpu_mem_free(chunk->obj_exts); +#endif pcpu_mem_free(chunk->md_blocks); pcpu_mem_free(chunk->bound_map); pcpu_mem_free(chunk->alloc_map); @@ -1223,17 +1499,13 @@ static void pcpu_free_chunk(struct pcpu_chunk *chunk) * @chunk: pcpu_chunk which got populated * @page_start: the start page * @page_end: the end page - * @for_alloc: if this is to populate for allocation * * Pages in [@page_start,@page_end) have been populated to @chunk. Update * the bookkeeping information accordingly. Must be called after each * successful population. - * - * If this is @for_alloc, do not increment pcpu_nr_empty_pop_pages because it - * is to serve an allocation in that area. */ static void pcpu_chunk_populated(struct pcpu_chunk *chunk, int page_start, - int page_end, bool for_alloc) + int page_end) { int nr = page_end - page_start; @@ -1243,10 +1515,7 @@ static void pcpu_chunk_populated(struct pcpu_chunk *chunk, int page_start, chunk->nr_populated += nr; pcpu_nr_populated += nr; - if (!for_alloc) { - chunk->nr_empty_pop_pages += nr; - pcpu_nr_empty_pop_pages += nr; - } + pcpu_update_empty_pages(chunk, nr); } /** @@ -1268,9 +1537,9 @@ static void pcpu_chunk_depopulated(struct pcpu_chunk *chunk, bitmap_clear(chunk->populated, page_start, nr); chunk->nr_populated -= nr; - chunk->nr_empty_pop_pages -= nr; - pcpu_nr_empty_pop_pages -= nr; pcpu_nr_populated -= nr; + + pcpu_update_empty_pages(chunk, -nr); } /* @@ -1283,6 +1552,7 @@ static void pcpu_chunk_depopulated(struct pcpu_chunk *chunk, * * pcpu_populate_chunk - populate the specified range of a chunk * pcpu_depopulate_chunk - depopulate the specified range of a chunk + * pcpu_post_unmap_tlb_flush - flush tlb for the specified range of a chunk * pcpu_create_chunk - create a new chunk * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop * pcpu_addr_to_page - translate address to physical address @@ -1292,6 +1562,8 @@ static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int page_start, int page_end, gfp_t gfp); static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int page_start, int page_end); +static void pcpu_post_unmap_tlb_flush(struct pcpu_chunk *chunk, + int page_start, int page_end); static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp); static void pcpu_destroy_chunk(struct pcpu_chunk *chunk); static struct page *pcpu_addr_to_page(void *addr); @@ -1334,6 +1606,112 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) return pcpu_get_page_chunk(pcpu_addr_to_page(addr)); } +#ifdef CONFIG_MEMCG +static bool pcpu_memcg_pre_alloc_hook(size_t size, gfp_t gfp, + struct obj_cgroup **objcgp) +{ + struct obj_cgroup *objcg; + + if (!memcg_kmem_online() || !(gfp & __GFP_ACCOUNT)) + return true; + + objcg = current_obj_cgroup(); + if (!objcg) + return true; + + if (obj_cgroup_charge(objcg, gfp, pcpu_obj_full_size(size))) + return false; + + *objcgp = objcg; + return true; +} + +static void pcpu_memcg_post_alloc_hook(struct obj_cgroup *objcg, + struct pcpu_chunk *chunk, int off, + size_t size) +{ + if (!objcg) + return; + + if (likely(chunk && chunk->obj_exts)) { + obj_cgroup_get(objcg); + chunk->obj_exts[off >> PCPU_MIN_ALLOC_SHIFT].cgroup = objcg; + + rcu_read_lock(); + mod_memcg_state(obj_cgroup_memcg(objcg), MEMCG_PERCPU_B, + pcpu_obj_full_size(size)); + rcu_read_unlock(); + } else { + obj_cgroup_uncharge(objcg, pcpu_obj_full_size(size)); + } +} + +static void pcpu_memcg_free_hook(struct pcpu_chunk *chunk, int off, size_t size) +{ + struct obj_cgroup *objcg; + + if (unlikely(!chunk->obj_exts)) + return; + + objcg = chunk->obj_exts[off >> PCPU_MIN_ALLOC_SHIFT].cgroup; + if (!objcg) + return; + chunk->obj_exts[off >> PCPU_MIN_ALLOC_SHIFT].cgroup = NULL; + + obj_cgroup_uncharge(objcg, pcpu_obj_full_size(size)); + + rcu_read_lock(); + mod_memcg_state(obj_cgroup_memcg(objcg), MEMCG_PERCPU_B, + -pcpu_obj_full_size(size)); + rcu_read_unlock(); + + obj_cgroup_put(objcg); +} + +#else /* CONFIG_MEMCG */ +static bool +pcpu_memcg_pre_alloc_hook(size_t size, gfp_t gfp, struct obj_cgroup **objcgp) +{ + return true; +} + +static void pcpu_memcg_post_alloc_hook(struct obj_cgroup *objcg, + struct pcpu_chunk *chunk, int off, + size_t size) +{ +} + +static void pcpu_memcg_free_hook(struct pcpu_chunk *chunk, int off, size_t size) +{ +} +#endif /* CONFIG_MEMCG */ + +#ifdef CONFIG_MEM_ALLOC_PROFILING +static void pcpu_alloc_tag_alloc_hook(struct pcpu_chunk *chunk, int off, + size_t size) +{ + if (mem_alloc_profiling_enabled() && likely(chunk->obj_exts)) { + alloc_tag_add(&chunk->obj_exts[off >> PCPU_MIN_ALLOC_SHIFT].tag, + current->alloc_tag, size); + } +} + +static void pcpu_alloc_tag_free_hook(struct pcpu_chunk *chunk, int off, size_t size) +{ + if (mem_alloc_profiling_enabled() && likely(chunk->obj_exts)) + alloc_tag_sub(&chunk->obj_exts[off >> PCPU_MIN_ALLOC_SHIFT].tag, size); +} +#else +static void pcpu_alloc_tag_alloc_hook(struct pcpu_chunk *chunk, int off, + size_t size) +{ +} + +static void pcpu_alloc_tag_free_hook(struct pcpu_chunk *chunk, int off, size_t size) +{ +} +#endif + /** * pcpu_alloc - the percpu allocator * @size: size of area to allocate in bytes @@ -1349,21 +1727,27 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) * RETURNS: * Percpu pointer to the allocated area on success, NULL on failure. */ -static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, +void __percpu *pcpu_alloc_noprof(size_t size, size_t align, bool reserved, gfp_t gfp) { - /* whitelisted flags that can be passed to the backing allocators */ - gfp_t pcpu_gfp = gfp & (GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN); - bool is_atomic = (gfp & GFP_KERNEL) != GFP_KERNEL; - bool do_warn = !(gfp & __GFP_NOWARN); - static int warn_limit = 10; - struct pcpu_chunk *chunk; + gfp_t pcpu_gfp; + bool is_atomic; + bool do_warn; + struct obj_cgroup *objcg = NULL; + static atomic_t warn_limit = ATOMIC_INIT(10); + struct pcpu_chunk *chunk, *next; const char *err; int slot, off, cpu, ret; unsigned long flags; void __percpu *ptr; size_t bits, bit_align; + gfp = current_gfp_context(gfp); + /* whitelisted flags that can be passed to the backing allocators */ + pcpu_gfp = gfp & (GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN); + is_atomic = !gfpflags_allow_blocking(gfp); + do_warn = !(gfp & __GFP_NOWARN); + /* * There is now a minimum allocation size of PCPU_MIN_ALLOC_SIZE, * therefore alignment must be a minimum of that many bytes. @@ -1384,16 +1768,21 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, return NULL; } + if (unlikely(!pcpu_memcg_pre_alloc_hook(size, gfp, &objcg))) + return NULL; + if (!is_atomic) { /* * pcpu_balance_workfn() allocates memory under this mutex, * and it may wait for memory reclaim. Allow current task * to become OOM victim, in case of memory pressure. */ - if (gfp & __GFP_NOFAIL) + if (gfp & __GFP_NOFAIL) { mutex_lock(&pcpu_alloc_mutex); - else if (mutex_lock_killable(&pcpu_alloc_mutex)) + } else if (mutex_lock_killable(&pcpu_alloc_mutex)) { + pcpu_memcg_post_alloc_hook(objcg, NULL, 0, size); return NULL; + } } spin_lock_irqsave(&pcpu_lock, flags); @@ -1418,33 +1807,34 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, restart: /* search through normal chunks */ - for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { - list_for_each_entry(chunk, &pcpu_slot[slot], list) { + for (slot = pcpu_size_to_slot(size); slot <= pcpu_free_slot; slot++) { + list_for_each_entry_safe(chunk, next, &pcpu_chunk_lists[slot], + list) { off = pcpu_find_block_fit(chunk, bits, bit_align, is_atomic); - if (off < 0) + if (off < 0) { + if (slot < PCPU_SLOT_FAIL_THRESHOLD) + pcpu_chunk_move(chunk, 0); continue; + } off = pcpu_alloc_area(chunk, bits, bit_align, off); - if (off >= 0) + if (off >= 0) { + pcpu_reintegrate_chunk(chunk); goto area_found; - + } } } spin_unlock_irqrestore(&pcpu_lock, flags); - /* - * No space left. Create a new chunk. We don't want multiple - * tasks to create chunks simultaneously. Serialize and create iff - * there's still no empty chunk after grabbing the mutex. - */ if (is_atomic) { err = "atomic alloc failed, no space left"; goto fail; } - if (list_empty(&pcpu_slot[pcpu_nr_slots - 1])) { + /* No space left. Create a new chunk. */ + if (list_empty(&pcpu_chunk_lists[pcpu_free_slot])) { chunk = pcpu_create_chunk(pcpu_gfp); if (!chunk) { err = "failed to allocate new chunk"; @@ -1461,17 +1851,20 @@ restart: area_found: pcpu_stats_area_alloc(chunk, size); + + if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW) + pcpu_schedule_balance_work(); + spin_unlock_irqrestore(&pcpu_lock, flags); /* populate if not all pages are already there */ if (!is_atomic) { - int page_start, page_end, rs, re; + unsigned int page_end, rs, re; - page_start = PFN_DOWN(off); + rs = PFN_DOWN(off); page_end = PFN_UP(off + size); - pcpu_for_each_unpop_region(chunk->populated, rs, re, - page_start, page_end) { + for_each_clear_bitrange_from(rs, re, chunk->populated, page_end) { WARN_ON(chunk->immutable); ret = pcpu_populate_chunk(chunk, rs, re, pcpu_gfp); @@ -1482,16 +1875,13 @@ area_found: err = "failed to populate"; goto fail_unlock; } - pcpu_chunk_populated(chunk, rs, re, true); + pcpu_chunk_populated(chunk, rs, re); spin_unlock_irqrestore(&pcpu_lock, flags); } mutex_unlock(&pcpu_alloc_mutex); } - if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW) - pcpu_schedule_balance_work(); - /* clear the areas and return address relative to base address */ for_each_possible_cpu(cpu) memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size); @@ -1499,8 +1889,13 @@ area_found: ptr = __addr_to_pcpu_ptr(chunk->base_addr + off); kmemleak_alloc_percpu(ptr, size, gfp); - trace_percpu_alloc_percpu(reserved, is_atomic, size, align, - chunk->base_addr, off, ptr); + trace_percpu_alloc_percpu(_RET_IP_, reserved, is_atomic, size, align, + chunk->base_addr, off, ptr, + pcpu_obj_full_size(size), gfp); + + pcpu_memcg_post_alloc_hook(objcg, chunk, off, size); + + pcpu_alloc_tag_alloc_hook(chunk, off, size); return ptr; @@ -1509,105 +1904,56 @@ fail_unlock: fail: trace_percpu_alloc_percpu_fail(reserved, is_atomic, size, align); - if (!is_atomic && do_warn && warn_limit) { - pr_warn("allocation failed, size=%zu align=%zu atomic=%d, %s\n", - size, align, is_atomic, err); - dump_stack(); - if (!--warn_limit) - pr_info("limit reached, disable warning\n"); + if (do_warn) { + int remaining = atomic_dec_if_positive(&warn_limit); + + if (remaining >= 0) { + pr_warn("allocation failed, size=%zu align=%zu atomic=%d, %s\n", + size, align, is_atomic, err); + if (!is_atomic) + dump_stack(); + if (remaining == 0) + pr_info("limit reached, disable warning\n"); + } } + if (is_atomic) { - /* see the flag handling in pcpu_blance_workfn() */ + /* see the flag handling in pcpu_balance_workfn() */ pcpu_atomic_alloc_failed = true; pcpu_schedule_balance_work(); } else { mutex_unlock(&pcpu_alloc_mutex); } - return NULL; -} -/** - * __alloc_percpu_gfp - allocate dynamic percpu area - * @size: size of area to allocate in bytes - * @align: alignment of area (max PAGE_SIZE) - * @gfp: allocation flags - * - * Allocate zero-filled percpu area of @size bytes aligned at @align. If - * @gfp doesn't contain %GFP_KERNEL, the allocation doesn't block and can - * be called from any context but is a lot more likely to fail. If @gfp - * has __GFP_NOWARN then no warning will be triggered on invalid or failed - * allocation requests. - * - * RETURNS: - * Percpu pointer to the allocated area on success, NULL on failure. - */ -void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) -{ - return pcpu_alloc(size, align, false, gfp); -} -EXPORT_SYMBOL_GPL(__alloc_percpu_gfp); + pcpu_memcg_post_alloc_hook(objcg, NULL, 0, size); -/** - * __alloc_percpu - allocate dynamic percpu area - * @size: size of area to allocate in bytes - * @align: alignment of area (max PAGE_SIZE) - * - * Equivalent to __alloc_percpu_gfp(size, align, %GFP_KERNEL). - */ -void __percpu *__alloc_percpu(size_t size, size_t align) -{ - return pcpu_alloc(size, align, false, GFP_KERNEL); + return NULL; } -EXPORT_SYMBOL_GPL(__alloc_percpu); +EXPORT_SYMBOL_GPL(pcpu_alloc_noprof); /** - * __alloc_reserved_percpu - allocate reserved percpu area - * @size: size of area to allocate in bytes - * @align: alignment of area (max PAGE_SIZE) + * pcpu_balance_free - manage the amount of free chunks + * @empty_only: free chunks only if there are no populated pages * - * Allocate zero-filled percpu area of @size bytes aligned at @align - * from reserved percpu area if arch has set it up; otherwise, - * allocation is served from the same dynamic area. Might sleep. - * Might trigger writeouts. + * If empty_only is %false, reclaim all fully free chunks regardless of the + * number of populated pages. Otherwise, only reclaim chunks that have no + * populated pages. * * CONTEXT: - * Does GFP_KERNEL allocation. - * - * RETURNS: - * Percpu pointer to the allocated area on success, NULL on failure. + * pcpu_lock (can be dropped temporarily) */ -void __percpu *__alloc_reserved_percpu(size_t size, size_t align) +static void pcpu_balance_free(bool empty_only) { - return pcpu_alloc(size, align, true, GFP_KERNEL); -} - -/** - * pcpu_balance_workfn - manage the amount of free chunks and populated pages - * @work: unused - * - * Reclaim all fully free chunks except for the first one. This is also - * responsible for maintaining the pool of empty populated pages. However, - * it is possible that this is called when physical memory is scarce causing - * OOM killer to be triggered. We should avoid doing so until an actual - * allocation causes the failure as it is possible that requests can be - * serviced from already backed regions. - */ -static void pcpu_balance_workfn(struct work_struct *work) -{ - /* gfp flags passed to underlying allocators */ - const gfp_t gfp = GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN; LIST_HEAD(to_free); - struct list_head *free_head = &pcpu_slot[pcpu_nr_slots - 1]; + struct list_head *free_head = &pcpu_chunk_lists[pcpu_free_slot]; struct pcpu_chunk *chunk, *next; - int slot, nr_to_pop, ret; + + lockdep_assert_held(&pcpu_lock); /* * There's no reason to keep around multiple unused chunks and VM * areas can be scarce. Destroy all free chunks except for one. */ - mutex_lock(&pcpu_alloc_mutex); - spin_lock_irq(&pcpu_lock); - list_for_each_entry_safe(chunk, next, free_head, list) { WARN_ON(chunk->immutable); @@ -1615,16 +1961,18 @@ static void pcpu_balance_workfn(struct work_struct *work) if (chunk == list_first_entry(free_head, struct pcpu_chunk, list)) continue; - list_move(&chunk->list, &to_free); + if (!empty_only || chunk->nr_empty_pop_pages == 0) + list_move(&chunk->list, &to_free); } - spin_unlock_irq(&pcpu_lock); + if (list_empty(&to_free)) + return; + spin_unlock_irq(&pcpu_lock); list_for_each_entry_safe(chunk, next, &to_free, list) { - int rs, re; + unsigned int rs, re; - pcpu_for_each_pop_region(chunk->populated, rs, re, 0, - chunk->nr_pages) { + for_each_set_bitrange(rs, re, chunk->populated, chunk->nr_pages) { pcpu_depopulate_chunk(chunk, rs, re); spin_lock_irq(&pcpu_lock); pcpu_chunk_depopulated(chunk, rs, re); @@ -1633,6 +1981,29 @@ static void pcpu_balance_workfn(struct work_struct *work) pcpu_destroy_chunk(chunk); cond_resched(); } + spin_lock_irq(&pcpu_lock); +} + +/** + * pcpu_balance_populated - manage the amount of populated pages + * + * Maintain a certain amount of populated pages to satisfy atomic allocations. + * It is possible that this is called when physical memory is scarce causing + * OOM killer to be triggered. We should avoid doing so until an actual + * allocation causes the failure as it is possible that requests can be + * serviced from already backed regions. + * + * CONTEXT: + * pcpu_lock (can be dropped temporarily) + */ +static void pcpu_balance_populated(void) +{ + /* gfp flags passed to underlying allocators */ + const gfp_t gfp = GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN; + struct pcpu_chunk *chunk; + int slot, nr_to_pop, ret; + + lockdep_assert_held(&pcpu_lock); /* * Ensure there are certain number of free populated pages for @@ -1655,34 +2026,32 @@ retry_pop: 0, PCPU_EMPTY_POP_PAGES_HIGH); } - for (slot = pcpu_size_to_slot(PAGE_SIZE); slot < pcpu_nr_slots; slot++) { - int nr_unpop = 0, rs, re; + for (slot = pcpu_size_to_slot(PAGE_SIZE); slot <= pcpu_free_slot; slot++) { + unsigned int nr_unpop = 0, rs, re; if (!nr_to_pop) break; - spin_lock_irq(&pcpu_lock); - list_for_each_entry(chunk, &pcpu_slot[slot], list) { + list_for_each_entry(chunk, &pcpu_chunk_lists[slot], list) { nr_unpop = chunk->nr_pages - chunk->nr_populated; if (nr_unpop) break; } - spin_unlock_irq(&pcpu_lock); if (!nr_unpop) continue; /* @chunk can't go away while pcpu_alloc_mutex is held */ - pcpu_for_each_unpop_region(chunk->populated, rs, re, 0, - chunk->nr_pages) { - int nr = min(re - rs, nr_to_pop); + for_each_clear_bitrange(rs, re, chunk->populated, chunk->nr_pages) { + int nr = min_t(int, re - rs, nr_to_pop); + spin_unlock_irq(&pcpu_lock); ret = pcpu_populate_chunk(chunk, rs, rs + nr, gfp); + cond_resched(); + spin_lock_irq(&pcpu_lock); if (!ret) { nr_to_pop -= nr; - spin_lock_irq(&pcpu_lock); - pcpu_chunk_populated(chunk, rs, rs + nr, false); - spin_unlock_irq(&pcpu_lock); + pcpu_chunk_populated(chunk, rs, rs + nr); } else { nr_to_pop = 0; } @@ -1694,16 +2063,155 @@ retry_pop: if (nr_to_pop) { /* ran out of chunks to populate, create a new one and retry */ + spin_unlock_irq(&pcpu_lock); chunk = pcpu_create_chunk(gfp); + cond_resched(); + spin_lock_irq(&pcpu_lock); if (chunk) { - spin_lock_irq(&pcpu_lock); pcpu_chunk_relocate(chunk, -1); - spin_unlock_irq(&pcpu_lock); goto retry_pop; } } +} +/** + * pcpu_reclaim_populated - scan over to_depopulate chunks and free empty pages + * + * Scan over chunks in the depopulate list and try to release unused populated + * pages back to the system. Depopulated chunks are sidelined to prevent + * repopulating these pages unless required. Fully free chunks are reintegrated + * and freed accordingly (1 is kept around). If we drop below the empty + * populated pages threshold, reintegrate the chunk if it has empty free pages. + * Each chunk is scanned in the reverse order to keep populated pages close to + * the beginning of the chunk. + * + * CONTEXT: + * pcpu_lock (can be dropped temporarily) + * + */ +static void pcpu_reclaim_populated(void) +{ + struct pcpu_chunk *chunk; + struct pcpu_block_md *block; + int freed_page_start, freed_page_end; + int i, end; + bool reintegrate; + + lockdep_assert_held(&pcpu_lock); + + /* + * Once a chunk is isolated to the to_depopulate list, the chunk is no + * longer discoverable to allocations whom may populate pages. The only + * other accessor is the free path which only returns area back to the + * allocator not touching the populated bitmap. + */ + while ((chunk = list_first_entry_or_null( + &pcpu_chunk_lists[pcpu_to_depopulate_slot], + struct pcpu_chunk, list))) { + WARN_ON(chunk->immutable); + + /* + * Scan chunk's pages in the reverse order to keep populated + * pages close to the beginning of the chunk. + */ + freed_page_start = chunk->nr_pages; + freed_page_end = 0; + reintegrate = false; + for (i = chunk->nr_pages - 1, end = -1; i >= 0; i--) { + /* no more work to do */ + if (chunk->nr_empty_pop_pages == 0) + break; + + /* reintegrate chunk to prevent atomic alloc failures */ + if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_HIGH) { + reintegrate = true; + break; + } + + /* + * If the page is empty and populated, start or + * extend the (i, end) range. If i == 0, decrease + * i and perform the depopulation to cover the last + * (first) page in the chunk. + */ + block = chunk->md_blocks + i; + if (block->contig_hint == PCPU_BITMAP_BLOCK_BITS && + test_bit(i, chunk->populated)) { + if (end == -1) + end = i; + if (i > 0) + continue; + i--; + } + + /* depopulate if there is an active range */ + if (end == -1) + continue; + + spin_unlock_irq(&pcpu_lock); + pcpu_depopulate_chunk(chunk, i + 1, end + 1); + cond_resched(); + spin_lock_irq(&pcpu_lock); + + pcpu_chunk_depopulated(chunk, i + 1, end + 1); + freed_page_start = min(freed_page_start, i + 1); + freed_page_end = max(freed_page_end, end + 1); + + /* reset the range and continue */ + end = -1; + } + + /* batch tlb flush per chunk to amortize cost */ + if (freed_page_start < freed_page_end) { + spin_unlock_irq(&pcpu_lock); + pcpu_post_unmap_tlb_flush(chunk, + freed_page_start, + freed_page_end); + cond_resched(); + spin_lock_irq(&pcpu_lock); + } + + if (reintegrate || chunk->free_bytes == pcpu_unit_size) + pcpu_reintegrate_chunk(chunk); + else + list_move_tail(&chunk->list, + &pcpu_chunk_lists[pcpu_sidelined_slot]); + } +} + +/** + * pcpu_balance_workfn - manage the amount of free chunks and populated pages + * @work: unused + * + * For each chunk type, manage the number of fully free chunks and the number of + * populated pages. An important thing to consider is when pages are freed and + * how they contribute to the global counts. + */ +static void pcpu_balance_workfn(struct work_struct *work) +{ + /* + * pcpu_balance_free() is called twice because the first time we may + * trim pages in the active pcpu_nr_empty_pop_pages which may cause us + * to grow other chunks. This then gives pcpu_reclaim_populated() time + * to move fully free chunks to the active list to be freed if + * appropriate. + * + * Enforce GFP_NOIO allocations because we have pcpu_alloc users + * constrained to GFP_NOIO/NOFS contexts and they could form lock + * dependency through pcpu_alloc_mutex + */ + unsigned int flags = memalloc_noio_save(); + mutex_lock(&pcpu_alloc_mutex); + spin_lock_irq(&pcpu_lock); + + pcpu_balance_free(false); + pcpu_reclaim_populated(); + pcpu_balance_populated(); + pcpu_balance_free(true); + + spin_unlock_irq(&pcpu_lock); mutex_unlock(&pcpu_alloc_mutex); + memalloc_noio_restore(flags); } /** @@ -1720,7 +2228,8 @@ void free_percpu(void __percpu *ptr) void *addr; struct pcpu_chunk *chunk; unsigned long flags; - int off; + int size, off; + bool need_balance = false; if (!ptr) return; @@ -1728,28 +2237,40 @@ void free_percpu(void __percpu *ptr) kmemleak_free_percpu(ptr); addr = __pcpu_ptr_to_addr(ptr); + chunk = pcpu_chunk_addr_search(addr); + off = addr - chunk->base_addr; spin_lock_irqsave(&pcpu_lock, flags); + size = pcpu_free_area(chunk, off); - chunk = pcpu_chunk_addr_search(addr); - off = addr - chunk->base_addr; + pcpu_alloc_tag_free_hook(chunk, off, size); - pcpu_free_area(chunk, off); + pcpu_memcg_free_hook(chunk, off, size); - /* if there are more than one fully free chunks, wake up grim reaper */ - if (chunk->free_bytes == pcpu_unit_size) { + /* + * If there are more than one fully free chunks, wake up grim reaper. + * If the chunk is isolated, it may be in the process of being + * reclaimed. Let reclaim manage cleaning up of that chunk. + */ + if (!chunk->isolated && chunk->free_bytes == pcpu_unit_size) { struct pcpu_chunk *pos; - list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) + list_for_each_entry(pos, &pcpu_chunk_lists[pcpu_free_slot], list) if (pos != chunk) { - pcpu_schedule_balance_work(); + need_balance = true; break; } + } else if (pcpu_should_reclaim_chunk(chunk)) { + pcpu_isolate_chunk(chunk); + need_balance = true; } trace_percpu_free_percpu(chunk->base_addr, off, ptr); spin_unlock_irqrestore(&pcpu_lock, flags); + + if (need_balance) + pcpu_schedule_balance_work(); } EXPORT_SYMBOL_GPL(free_percpu); @@ -1884,11 +2405,11 @@ struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, void *ptr; int unit; - base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), + base_size = ALIGN(struct_size(ai, groups, nr_groups), __alignof__(ai->groups[0].cpu_map[0])); ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]); - ptr = memblock_alloc_nopanic(PFN_ALIGN(ai_size), PAGE_SIZE); + ptr = memblock_alloc(PFN_ALIGN(ai_size), PAGE_SIZE); if (!ptr) return NULL; ai = ptr; @@ -1913,7 +2434,7 @@ struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, */ void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) { - memblock_free_early(__pa(ai), ai->__ai_size); + memblock_free(ai, ai->__ai_size); } /** @@ -1979,7 +2500,7 @@ static void pcpu_dump_alloc_info(const char *lvl, * @base_addr: mapped address * * Initialize the first percpu chunk which contains the kernel static - * perpcu area. This function is to be called from arch percpu area + * percpu area. This function is to be called from arch percpu area * setup path. * * @ai contains all information necessary to initialize the first @@ -2026,24 +2547,20 @@ static void pcpu_dump_alloc_info(const char *lvl, * share the same vm, but use offset regions in the area allocation map. * The chunk serving the dynamic region is circulated in the chunk slots * and available for dynamic allocation like any other chunk. - * - * RETURNS: - * 0 on success, -errno on failure. */ -int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, - void *base_addr) +void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, + void *base_addr) { 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; #define PCPU_SETUP_BUG_ON(cond) do { \ if (unlikely(cond)) { \ @@ -2068,21 +2585,23 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE); PCPU_SETUP_BUG_ON(!IS_ALIGNED(ai->unit_size, PCPU_BITMAP_BLOCK_SIZE)); PCPU_SETUP_BUG_ON(ai->dyn_size < PERCPU_DYNAMIC_EARLY_SIZE); - PCPU_SETUP_BUG_ON(!ai->dyn_size); PCPU_SETUP_BUG_ON(!IS_ALIGNED(ai->reserved_size, PCPU_MIN_ALLOC_SIZE)); PCPU_SETUP_BUG_ON(!(IS_ALIGNED(PCPU_BITMAP_BLOCK_SIZE, PAGE_SIZE) || IS_ALIGNED(PAGE_SIZE, PCPU_BITMAP_BLOCK_SIZE))); PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0); /* process group information and build config tables accordingly */ - group_offsets = memblock_alloc(ai->nr_groups * sizeof(group_offsets[0]), - SMP_CACHE_BYTES); - group_sizes = memblock_alloc(ai->nr_groups * sizeof(group_sizes[0]), - SMP_CACHE_BYTES); - unit_map = memblock_alloc(nr_cpu_ids * sizeof(unit_map[0]), - SMP_CACHE_BYTES); - unit_off = memblock_alloc(nr_cpu_ids * sizeof(unit_off[0]), - SMP_CACHE_BYTES); + alloc_size = ai->nr_groups * sizeof(group_offsets[0]); + group_offsets = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES); + + alloc_size = ai->nr_groups * sizeof(group_sizes[0]); + group_sizes = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES); + + alloc_size = nr_cpu_ids * sizeof(unit_map[0]); + unit_map = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES); + + alloc_size = nr_cpu_ids * sizeof(unit_off[0]); + unit_off = memblock_alloc_or_panic(alloc_size, SMP_CACHE_BYTES); for (cpu = 0; cpu < nr_cpu_ids; cpu++) unit_map[cpu] = UINT_MAX; @@ -2136,20 +2655,27 @@ int __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 = sizeof(struct pcpu_chunk) + - BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long); + pcpu_chunk_struct_size = struct_size((struct pcpu_chunk *)0, populated, + BITS_TO_LONGS(pcpu_unit_pages)); pcpu_stats_save_ai(ai); /* - * Allocate chunk slots. The additional last slot is for - * empty chunks. + * Allocate chunk slots. The slots after the active slots are: + * sidelined_slot - isolated, depopulated chunks + * free_slot - fully free chunks + * to_depopulate_slot - isolated, chunks to depopulate */ - pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; - pcpu_slot = memblock_alloc(pcpu_nr_slots * sizeof(pcpu_slot[0]), - SMP_CACHE_BYTES); + pcpu_sidelined_slot = __pcpu_size_to_slot(pcpu_unit_size) + 1; + pcpu_free_slot = pcpu_sidelined_slot + 1; + pcpu_to_depopulate_slot = pcpu_free_slot + 1; + pcpu_nr_slots = pcpu_to_depopulate_slot + 1; + pcpu_chunk_lists = memblock_alloc_or_panic(pcpu_nr_slots * + sizeof(pcpu_chunk_lists[0]), + SMP_CACHE_BYTES); + for (i = 0; i < pcpu_nr_slots; i++) - INIT_LIST_HEAD(&pcpu_slot[i]); + INIT_LIST_HEAD(&pcpu_chunk_lists[i]); /* * The end of the static region needs to be aligned with the @@ -2163,29 +2689,23 @@ int __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); @@ -2197,7 +2717,6 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, /* we're done */ pcpu_base_addr = base_addr; - return 0; } #ifdef CONFIG_SMP @@ -2270,17 +2789,18 @@ early_param("percpu_alloc", percpu_alloc_setup); * On success, pointer to the new allocation_info is returned. On * failure, ERR_PTR value is returned. */ -static struct pcpu_alloc_info * __init pcpu_build_alloc_info( +static struct pcpu_alloc_info * __init __flatten 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) { static int group_map[NR_CPUS] __initdata; static int group_cnt[NR_CPUS] __initdata; + static struct cpumask mask __initdata; const size_t static_size = __per_cpu_end - __per_cpu_start; int nr_groups = 1, nr_units = 0; size_t size_sum, min_unit_size, alloc_size; - int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ + int upa, max_upa, best_upa; /* units_per_alloc */ int last_allocs, group, unit; unsigned int cpu, tcpu; struct pcpu_alloc_info *ai; @@ -2289,6 +2809,7 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info( /* this function may be called multiple times */ memset(group_map, 0, sizeof(group_map)); memset(group_cnt, 0, sizeof(group_cnt)); + cpumask_clear(&mask); /* calculate size_sum and ensure dyn_size is enough for early alloc */ size_sum = PFN_ALIGN(static_size + reserved_size + @@ -2310,24 +2831,27 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info( upa--; max_upa = upa; + cpumask_copy(&mask, cpu_possible_mask); + /* group cpus according to their proximity */ - for_each_possible_cpu(cpu) { - group = 0; - next_group: - for_each_possible_cpu(tcpu) { - if (cpu == tcpu) - break; - if (group_map[tcpu] == group && cpu_distance_fn && - (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || - cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { - group++; - nr_groups = max(nr_groups, group + 1); - goto next_group; - } - } + for (group = 0; !cpumask_empty(&mask); group++) { + /* pop the group's first cpu */ + cpu = cpumask_first(&mask); group_map[cpu] = group; group_cnt[group]++; + cpumask_clear_cpu(cpu, &mask); + + for_each_cpu(tcpu, &mask) { + if (!cpu_distance_fn || + (cpu_distance_fn(cpu, tcpu) == LOCAL_DISTANCE && + cpu_distance_fn(tcpu, cpu) == LOCAL_DISTANCE)) { + group_map[tcpu] = group; + group_cnt[group]++; + cpumask_clear_cpu(tcpu, &mask); + } + } } + nr_groups = group; /* * Wasted space is caused by a ratio imbalance of upa to group_cnt. @@ -2335,6 +2859,7 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info( * Related to atom_size, which could be much larger than the unit_size. */ last_allocs = INT_MAX; + best_upa = 0; for (upa = max_upa; upa; upa--) { int allocs = 0, wasted = 0; @@ -2361,6 +2886,7 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info( last_allocs = allocs; best_upa = upa; } + BUG_ON(!best_upa); upa = best_upa; /* allocate and fill alloc_info */ @@ -2384,7 +2910,7 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info( ai->atom_size = atom_size; ai->alloc_size = alloc_size; - for (group = 0, unit = 0; group_cnt[group]; group++) { + for (group = 0, unit = 0; group < nr_groups; group++) { struct pcpu_group_info *gi = &ai->groups[group]; /* @@ -2404,6 +2930,42 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info( return ai; } + +static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align, + pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn) +{ + const unsigned long goal = __pa(MAX_DMA_ADDRESS); +#ifdef CONFIG_NUMA + int node = NUMA_NO_NODE; + void *ptr; + + if (cpu_to_nd_fn) + node = cpu_to_nd_fn(cpu); + + if (node == NUMA_NO_NODE || !node_online(node) || !NODE_DATA(node)) { + ptr = memblock_alloc_from(size, align, goal); + pr_info("cpu %d has no node %d or node-local memory\n", + cpu, node); + pr_debug("per cpu data for cpu%d %zu bytes at 0x%llx\n", + cpu, size, (u64)__pa(ptr)); + } else { + ptr = memblock_alloc_try_nid(size, align, goal, + MEMBLOCK_ALLOC_ACCESSIBLE, + node); + + pr_debug("per cpu data for cpu%d %zu bytes on node%d at 0x%llx\n", + cpu, size, node, (u64)__pa(ptr)); + } + return ptr; +#else + return memblock_alloc_from(size, align, goal); +#endif +} + +static void __init pcpu_fc_free(void *ptr, size_t size) +{ + memblock_free(ptr, size); +} #endif /* BUILD_EMBED_FIRST_CHUNK || BUILD_PAGE_FIRST_CHUNK */ #if defined(BUILD_EMBED_FIRST_CHUNK) @@ -2413,14 +2975,13 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info( * @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 - * @free_fn: function to free percpu page + * @cpu_to_nd_fn: callback to convert cpu to it's node, optional * * This is a helper to ease setting up embedded first percpu chunk and * can be called where pcpu_setup_first_chunk() is expected. * * If this function is used to setup the first chunk, it is allocated - * by calling @alloc_fn and used as-is without being mapped into + * by calling pcpu_fc_alloc and used as-is without being mapped into * vmalloc area. Allocations are always whole multiples of @atom_size * aligned to @atom_size. * @@ -2434,7 +2995,7 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info( * @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. + * size, the leftover is returned using pcpu_fc_free. * * RETURNS: * 0 on success, -errno on failure. @@ -2442,15 +3003,14 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info( 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, - pcpu_fc_free_fn_t free_fn) + pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn) { void *base = (void *)ULONG_MAX; void **areas = NULL; struct pcpu_alloc_info *ai; size_t size_sum, areas_size; unsigned long max_distance; - int group, i, highest_group, rc; + int group, i, highest_group, rc = 0; ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, cpu_distance_fn); @@ -2460,7 +3020,7 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *)); - areas = memblock_alloc_nopanic(areas_size, SMP_CACHE_BYTES); + areas = memblock_alloc(areas_size, SMP_CACHE_BYTES); if (!areas) { rc = -ENOMEM; goto out_free; @@ -2478,13 +3038,13 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, BUG_ON(cpu == NR_CPUS); /* allocate space for the whole group */ - ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size); + ptr = pcpu_fc_alloc(cpu, gi->nr_units * ai->unit_size, atom_size, cpu_to_nd_fn); if (!ptr) { rc = -ENOMEM; goto out_free_areas; } /* kmemleak tracks the percpu allocations separately */ - kmemleak_free(ptr); + kmemleak_ignore_phys(__pa(ptr)); areas[group] = ptr; base = min(ptr, base); @@ -2517,12 +3077,12 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) { if (gi->cpu_map[i] == NR_CPUS) { /* unused unit, free whole */ - free_fn(ptr, ai->unit_size); + pcpu_fc_free(ptr, ai->unit_size); continue; } /* copy and return the unused part */ - memcpy(ptr, __per_cpu_load, ai->static_size); - free_fn(ptr + size_sum, ai->unit_size - size_sum); + memcpy(ptr, __per_cpu_start, ai->static_size); + pcpu_fc_free(ptr + size_sum, ai->unit_size - size_sum); } } @@ -2531,33 +3091,83 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, ai->groups[group].base_offset = areas[group] - base; } - pr_info("Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n", - PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size, + pr_info("Embedded %zu pages/cpu s%zu r%zu d%zu u%zu\n", + PFN_DOWN(size_sum), ai->static_size, ai->reserved_size, ai->dyn_size, ai->unit_size); - rc = pcpu_setup_first_chunk(ai, base); + pcpu_setup_first_chunk(ai, base); goto out_free; out_free_areas: for (group = 0; group < ai->nr_groups; group++) if (areas[group]) - free_fn(areas[group], + pcpu_fc_free(areas[group], ai->groups[group].nr_units * ai->unit_size); out_free: pcpu_free_alloc_info(ai); if (areas) - memblock_free_early(__pa(areas), areas_size); + memblock_free(areas, areas_size); return rc; } #endif /* BUILD_EMBED_FIRST_CHUNK */ #ifdef BUILD_PAGE_FIRST_CHUNK +#include <linux/pgalloc.h> + +#ifndef P4D_TABLE_SIZE +#define P4D_TABLE_SIZE PAGE_SIZE +#endif + +#ifndef PUD_TABLE_SIZE +#define PUD_TABLE_SIZE PAGE_SIZE +#endif + +#ifndef PMD_TABLE_SIZE +#define PMD_TABLE_SIZE PAGE_SIZE +#endif + +#ifndef PTE_TABLE_SIZE +#define PTE_TABLE_SIZE PAGE_SIZE +#endif +void __init __weak pcpu_populate_pte(unsigned long addr) +{ + pgd_t *pgd = pgd_offset_k(addr); + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + + if (pgd_none(*pgd)) { + p4d = memblock_alloc_or_panic(P4D_TABLE_SIZE, P4D_TABLE_SIZE); + pgd_populate_kernel(addr, pgd, p4d); + } + + p4d = p4d_offset(pgd, addr); + if (p4d_none(*p4d)) { + pud = memblock_alloc_or_panic(PUD_TABLE_SIZE, PUD_TABLE_SIZE); + p4d_populate_kernel(addr, p4d, pud); + } + + pud = pud_offset(p4d, addr); + if (pud_none(*pud)) { + pmd = memblock_alloc_or_panic(PMD_TABLE_SIZE, PMD_TABLE_SIZE); + pud_populate(&init_mm, pud, pmd); + } + + pmd = pmd_offset(pud, addr); + if (!pmd_present(*pmd)) { + pte_t *new; + + new = memblock_alloc_or_panic(PTE_TABLE_SIZE, PTE_TABLE_SIZE); + pmd_populate_kernel(&init_mm, pmd, new); + } + + return; +} + /** * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages * @reserved_size: the size of reserved percpu area in bytes - * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE - * @free_fn: function to free percpu page, always called with PAGE_SIZE - * @populate_pte_fn: function to populate pte + * @cpu_to_nd_fn: callback to convert cpu to it's node, optional * * This is a helper to ease setting up page-remapped first percpu * chunk and can be called where pcpu_setup_first_chunk() is expected. @@ -2568,10 +3178,7 @@ out_free: * RETURNS: * 0 on success, -errno on failure. */ -int __init pcpu_page_first_chunk(size_t reserved_size, - pcpu_fc_alloc_fn_t alloc_fn, - pcpu_fc_free_fn_t free_fn, - pcpu_fc_populate_pte_fn_t populate_pte_fn) +int __init pcpu_page_first_chunk(size_t reserved_size, pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn) { static struct vm_struct vm; struct pcpu_alloc_info *ai; @@ -2579,7 +3186,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size, int unit_pages; size_t pages_size; struct page **pages; - int unit, i, j, rc; + int unit, i, j, rc = 0; int upa; int nr_g0_units; @@ -2601,7 +3208,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size, /* unaligned allocations can't be freed, round up to page size */ pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() * sizeof(pages[0])); - pages = memblock_alloc(pages_size, SMP_CACHE_BYTES); + pages = memblock_alloc_or_panic(pages_size, SMP_CACHE_BYTES); /* allocate pages */ j = 0; @@ -2610,14 +3217,14 @@ int __init pcpu_page_first_chunk(size_t reserved_size, for (i = 0; i < unit_pages; i++) { void *ptr; - ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE); + ptr = pcpu_fc_alloc(cpu, PAGE_SIZE, PAGE_SIZE, cpu_to_nd_fn); if (!ptr) { pr_warn("failed to allocate %s page for cpu%u\n", psize_str, cpu); goto enomem; } /* kmemleak tracks the percpu allocations separately */ - kmemleak_free(ptr); + kmemleak_ignore_phys(__pa(ptr)); pages[j++] = virt_to_page(ptr); } } @@ -2632,7 +3239,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size, (unsigned long)vm.addr + unit * ai->unit_size; for (i = 0; i < unit_pages; i++) - populate_pte_fn(unit_addr + (i << PAGE_SHIFT)); + pcpu_populate_pte(unit_addr + (i << PAGE_SHIFT)); /* pte already populated, the following shouldn't fail */ rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages], @@ -2640,32 +3247,26 @@ int __init pcpu_page_first_chunk(size_t reserved_size, if (rc < 0) panic("failed to map percpu area, err=%d\n", rc); - /* - * FIXME: Archs with virtual cache should flush local - * cache for the linear mapping here - something - * equivalent to flush_cache_vmap() on the local cpu. - * flush_cache_vmap() can't be used as most supporting - * data structures are not set up yet. - */ + flush_cache_vmap_early(unit_addr, unit_addr + ai->unit_size); /* copy static data */ - memcpy((void *)unit_addr, __per_cpu_load, ai->static_size); + memcpy((void *)unit_addr, __per_cpu_start, ai->static_size); } /* we're ready, commit */ - pr_info("%d %s pages/cpu @%p s%zu r%zu d%zu\n", - unit_pages, psize_str, vm.addr, ai->static_size, + pr_info("%d %s pages/cpu s%zu r%zu d%zu\n", + unit_pages, psize_str, ai->static_size, ai->reserved_size, ai->dyn_size); - rc = pcpu_setup_first_chunk(ai, vm.addr); + pcpu_setup_first_chunk(ai, vm.addr); goto out_free_ar; enomem: while (--j >= 0) - free_fn(page_address(pages[j]), PAGE_SIZE); + pcpu_fc_free(page_address(pages[j]), PAGE_SIZE); rc = -ENOMEM; out_free_ar: - memblock_free_early(__pa(pages), pages_size); + memblock_free(pages, pages_size); pcpu_free_alloc_info(ai); return rc; } @@ -2687,18 +3288,6 @@ out_free_ar: unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; EXPORT_SYMBOL(__per_cpu_offset); -static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size, - size_t align) -{ - return memblock_alloc_from_nopanic( - size, align, __pa(MAX_DMA_ADDRESS)); -} - -static void __init pcpu_dfl_fc_free(void *ptr, size_t size) -{ - memblock_free_early(__pa(ptr), size); -} - void __init setup_per_cpu_areas(void) { unsigned long delta; @@ -2709,9 +3298,8 @@ void __init setup_per_cpu_areas(void) * Always reserve area for module percpu variables. That's * what the legacy allocator did. */ - rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, - PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, - pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); + rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, PERCPU_DYNAMIC_RESERVE, + PAGE_SIZE, NULL, NULL); if (rc < 0) panic("Failed to initialize percpu areas."); @@ -2739,13 +3327,11 @@ void __init setup_per_cpu_areas(void) void *fc; ai = pcpu_alloc_alloc_info(1, 1); - fc = memblock_alloc_from_nopanic(unit_size, - PAGE_SIZE, - __pa(MAX_DMA_ADDRESS)); + fc = memblock_alloc_from(unit_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS)); if (!ai || !fc) panic("Failed to allocate memory for percpu areas."); /* kmemleak tracks the percpu allocations separately */ - kmemleak_free(fc); + kmemleak_ignore_phys(__pa(fc)); ai->dyn_size = unit_size; ai->unit_size = unit_size; @@ -2754,8 +3340,7 @@ void __init setup_per_cpu_areas(void) ai->groups[0].nr_units = 1; ai->groups[0].cpu_map[0] = 0; - if (pcpu_setup_first_chunk(ai, fc) < 0) - panic("Failed to initialize percpu areas."); + pcpu_setup_first_chunk(ai, fc); pcpu_free_alloc_info(ai); } @@ -2774,7 +3359,7 @@ void __init setup_per_cpu_areas(void) */ unsigned long pcpu_nr_pages(void) { - return pcpu_nr_populated * pcpu_nr_units; + return data_race(READ_ONCE(pcpu_nr_populated)) * pcpu_nr_units; } /* |