diff options
| -rw-r--r-- | fs/btrfs/free-space-cache.c | 35 |
1 files changed, 21 insertions, 14 deletions
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 4eb29642606..5c2caad7621 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -259,7 +259,9 @@ static int link_free_space(struct btrfs_block_group_cache *block_group, static void recalculate_thresholds(struct btrfs_block_group_cache *block_group) { - u64 max_bytes, possible_bytes; + u64 max_bytes; + u64 bitmap_bytes; + u64 extent_bytes; /* * The goal is to keep the total amount of memory used per 1gb of space @@ -269,22 +271,27 @@ static void recalculate_thresholds(struct btrfs_block_group_cache *block_group) max_bytes = MAX_CACHE_BYTES_PER_GIG * (div64_u64(block_group->key.offset, 1024 * 1024 * 1024)); - possible_bytes = (block_group->total_bitmaps * PAGE_CACHE_SIZE) + - (sizeof(struct btrfs_free_space) * - block_group->extents_thresh); + /* + * we want to account for 1 more bitmap than what we have so we can make + * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as + * we add more bitmaps. + */ + bitmap_bytes = (block_group->total_bitmaps + 1) * PAGE_CACHE_SIZE; - if (possible_bytes > max_bytes) { - int extent_bytes = max_bytes - - (block_group->total_bitmaps * PAGE_CACHE_SIZE); + if (bitmap_bytes >= max_bytes) { + block_group->extents_thresh = 0; + return; + } - if (extent_bytes <= 0) { - block_group->extents_thresh = 0; - return; - } + /* + * we want the extent entry threshold to always be at most 1/2 the maxw + * bytes we can have, or whatever is less than that. + */ + extent_bytes = max_bytes - bitmap_bytes; + extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2)); - block_group->extents_thresh = extent_bytes / - (sizeof(struct btrfs_free_space)); - } + block_group->extents_thresh = + div64_u64(extent_bytes, (sizeof(struct btrfs_free_space))); } static void bitmap_clear_bits(struct btrfs_block_group_cache *block_group, |