diff options
Diffstat (limited to 'innobase/buf/buf0lru.c')
| -rw-r--r-- | innobase/buf/buf0lru.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/innobase/buf/buf0lru.c b/innobase/buf/buf0lru.c index 0f632f0752a..6984c196701 100644 --- a/innobase/buf/buf0lru.c +++ b/innobase/buf/buf0lru.c @@ -42,6 +42,11 @@ initial segment in buf_LRU_get_recent_limit */ #define BUF_LRU_INITIAL_RATIO 8 +/* When dropping the search hash index entries before deleting an ibd +file, we build a local array of pages belonging to that tablespace +in the buffer pool. Following is the size of that array. */ +#define BUF_LRU_DROP_SEARCH_HASH_SIZE 1024 + /* If we switch on the InnoDB monitor because there are too few available frames in the buffer pool, we set this to TRUE */ ibool buf_lru_switched_on_innodb_mon = FALSE; @@ -66,6 +71,120 @@ buf_LRU_block_free_hashed_page( be in a state where it can be freed */ /********************************************************************** +Attempts to drop page hash index on a batch of pages belonging to a +particular space id. */ +static +void +buf_LRU_drop_page_hash_batch( +/*=========================*/ + ulint id, /* in: space id */ + const ulint* arr, /* in: array of page_no */ + ulint count) /* in: number of entries in array */ +{ + ulint i; + + ut_ad(arr != NULL); + ut_ad(count <= BUF_LRU_DROP_SEARCH_HASH_SIZE); + + for (i = 0; i < count; ++i) { + btr_search_drop_page_hash_when_freed(id, arr[i]); + } +} + +/********************************************************************** +When doing a DROP TABLE/DISCARD TABLESPACE we have to drop all page +hash index entries belonging to that table. This function tries to +do that in batch. Note that this is a 'best effort' attempt and does +not guarantee that ALL hash entries will be removed. */ +static +void +buf_LRU_drop_page_hash_for_tablespace( +/*==================================*/ + ulint id) /* in: space id */ +{ + buf_block_t* block; + ulint* page_arr; + ulint num_entries; + + page_arr = ut_malloc(sizeof(ulint) + * BUF_LRU_DROP_SEARCH_HASH_SIZE); + mutex_enter(&buf_pool->mutex); + +scan_again: + num_entries = 0; + block = UT_LIST_GET_LAST(buf_pool->LRU); + + while (block != NULL) { + buf_block_t* prev_block; + + mutex_enter(&block->mutex); + prev_block = UT_LIST_GET_PREV(LRU, block); + + ut_a(block->state == BUF_BLOCK_FILE_PAGE); + + if (block->space != id + || block->buf_fix_count > 0 + || block->io_fix != 0) { + /* We leave the fixed pages as is in this scan. + To be dealt with later in the final scan. */ + mutex_exit(&block->mutex); + goto next_page; + } + + ut_ad(block->space == id); + if (block->is_hashed) { + + /* Store the offset(i.e.: page_no) in the array + so that we can drop hash index in a batch + later. */ + page_arr[num_entries] = block->offset; + mutex_exit(&block->mutex); + ut_a(num_entries < BUF_LRU_DROP_SEARCH_HASH_SIZE); + ++num_entries; + + if (num_entries < BUF_LRU_DROP_SEARCH_HASH_SIZE) { + goto next_page; + } + /* Array full. We release the buf_pool->mutex to + obey the latching order. */ + mutex_exit(&buf_pool->mutex); + + buf_LRU_drop_page_hash_batch(id, page_arr, + num_entries); + num_entries = 0; + mutex_enter(&buf_pool->mutex); + } else { + mutex_exit(&block->mutex); + } + +next_page: + /* Note that we may have released the buf_pool->mutex + above after reading the prev_block during processing + of a page_hash_batch (i.e.: when the array was full). + This means that prev_block can change in LRU list. + This is OK because this function is a 'best effort' + to drop as many search hash entries as possible and + it does not guarantee that ALL such entries will be + dropped. */ + block = prev_block; + + /* If, however, block has been removed from LRU list + to the free list then we should restart the scan. + block->state is protected by buf_pool->mutex. */ + if (block && block->state != BUF_BLOCK_FILE_PAGE) { + ut_a(num_entries == 0); + goto scan_again; + } + } + + mutex_exit(&buf_pool->mutex); + + /* Drop any remaining batch of search hashed pages. */ + buf_LRU_drop_page_hash_batch(id, page_arr, num_entries); + ut_free(page_arr); +} + +/********************************************************************** Invalidates all pages belonging to a given tablespace when we are deleting the data file(s) of that tablespace. */ @@ -78,6 +197,14 @@ buf_LRU_invalidate_tablespace( ulint page_no; ibool all_freed; + /* Before we attempt to drop pages one by one we first + attempt to drop page hash index entries in batches to make + it more efficient. The batching attempt is a best effort + attempt and does not guarantee that all pages hash entries + will be dropped. We get rid of remaining page hash entries + one by one below. */ + buf_LRU_drop_page_hash_for_tablespace(id); + scan_again: mutex_enter(&(buf_pool->mutex)); |