/* the slots are sorted by free bytes left, 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
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 */
return index * PCPU_BITMAP_BLOCK_BITS + off;
}
+ /*
+ * 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
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 */
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_slot[slot]);
+ else
+ list_move_tail(&chunk->list, &pcpu_slot[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
{
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]);
- }
- }
-
- /**
- * 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)
- {
- 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;
-
- /*
- * 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 (oslot != nslot)
+ __pcpu_chunk_move(chunk, nslot, oslot < nslot);
}
- /**
- * pcpu_chunk_update - updates the chunk metadata given a free area
+ /*
+ * pcpu_update_empty_pages - update empty page counters
* @chunk: chunk of interest
- * @bit_off: chunk offset
- * @bits: size of free area
+ * @nr: nr of empty pages
*
- * 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.
+ * 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_update(struct pcpu_chunk *chunk, int bit_off, int bits)
+ static inline void pcpu_update_empty_pages(struct pcpu_chunk *chunk, int nr)
{
- 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;
- }
+ chunk->nr_empty_pop_pages += nr;
+ if (chunk != pcpu_reserved_chunk)
+ pcpu_nr_empty_pop_pages += nr;
}
- /**
- * pcpu_chunk_refresh_hint - updates metadata about a chunk
- * @chunk: chunk of interest
- *
- * 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.
+ /*
+ * 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
*
- * Updates:
- * chunk->contig_bits
- * chunk->contig_bits_start
- * nr_empty_pop_pages (chunk and global)
+ * This is used to determine if the hint region [a, b) overlaps with the
+ * allocated region [x, y).
*/
- static void pcpu_chunk_refresh_hint(struct pcpu_chunk *chunk)
+ static inline bool pcpu_region_overlap(int a, int b, int x, int y)
{
- 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_empty_pop_pages;
+ return (a < y) && (x < b);
}
/**
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);
}
}
{
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 */
+ int rs, re, start; /* 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_for_each_unpop_region(alloc_map, rs, re, start,
PCPU_BITMAP_BLOCK_BITS) {
pcpu_block_update(block, rs, re);
}
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 */
* If the allocation breaks the contig_hint, a scan is required to
* restore this hint.
*/
+ if (s_block->contig_hint == PCPU_BITMAP_BLOCK_BITS)
+ nr_empty_pages++;
+
if (s_off == s_block->first_free)
s_block->first_free = find_next_zero_bit(
pcpu_index_alloc_map(chunk, s_index),
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 */
* 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.
/* 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);
}
/* 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;
}
}
+ 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);
}
/**
*
* 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 */
/* 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;
}
}
+ 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);
}
/**
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;
/*
* 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)
+ bit_off = ALIGN(chunk_md->contig_hint_start, align) -
+ chunk_md->contig_hint_start;
+ if (bit_off + alloc_bits > chunk_md->contig_hint)
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,
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
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);
/*
* 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);
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);
*/
static void pcpu_free_area(struct pcpu_chunk *chunk, int off)
{
+ struct pcpu_block_md *chunk_md = &chunk->chunk_md;
int bit_off, bits, end, oslot;
lockdep_assert_held(&pcpu_lock);
chunk->free_bytes += bits * PCPU_MIN_ALLOC_SIZE;
/* 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);
}
+ 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);
}
/**
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) {
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);
}
pcpu_init_md_blocks(chunk);
/* init metadata */
- chunk->contig_bits = region_bits;
chunk->free_bytes = chunk->nr_pages * PAGE_SIZE;
return 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
* 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;
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);
}
/**
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);
}
/*
bool is_atomic = (gfp & GFP_KERNEL) != GFP_KERNEL;
bool do_warn = !(gfp & __GFP_NOWARN);
static int warn_limit = 10;
- struct pcpu_chunk *chunk;
+ struct pcpu_chunk *chunk, *next;
const char *err;
int slot, off, cpu, ret;
unsigned long flags;
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) {
+ list_for_each_entry_safe(chunk, next, &pcpu_slot[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)
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);
}
if (!ret) {
nr_to_pop -= nr;
spin_lock_irq(&pcpu_lock);
- pcpu_chunk_populated(chunk, rs, rs + nr, false);
+ pcpu_chunk_populated(chunk, rs, rs + nr);
spin_unlock_irq(&pcpu_lock);
} else {
nr_to_pop = 0;
struct pcpu_chunk *chunk;
unsigned long flags;
int off;
+ bool need_balance = false;
if (!ptr)
return;
list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list)
if (pos != chunk) {
- pcpu_schedule_balance_work();
+ need_balance = true;
break;
}
}
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);
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);
}
/* 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);
projects / linux-2.6-block.git / commitdiff