diff options
Diffstat (limited to 'storage/xtradb/buf/buf0lru.c')
| -rw-r--r-- | storage/xtradb/buf/buf0lru.c | 141 |
1 files changed, 99 insertions, 42 deletions
diff --git a/storage/xtradb/buf/buf0lru.c b/storage/xtradb/buf/buf0lru.c index 58e2c23275b..65fdf342e4f 100644 --- a/storage/xtradb/buf/buf0lru.c +++ b/storage/xtradb/buf/buf0lru.c @@ -1,6 +1,6 @@ /***************************************************************************** -Copyright (c) 1995, 2009, Innobase Oy. All Rights Reserved. +Copyright (c) 1995, 2010, Innobase Oy. All Rights Reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software @@ -371,21 +371,39 @@ scan_again: bpage = UT_LIST_GET_LAST(buf_pool->LRU); while (bpage != NULL) { - mutex_t* block_mutex = buf_page_get_mutex_enter(bpage); buf_page_t* prev_bpage; + ibool prev_bpage_buf_fix = FALSE; ut_a(buf_page_in_file(bpage)); prev_bpage = UT_LIST_GET_PREV(LRU, bpage); - if (!block_mutex) { - bpage = prev_bpage; - continue; - } + /* bpage->space and bpage->io_fix are protected by + buf_pool_mutex and block_mutex. It is safe to check + them while holding buf_pool_mutex only. */ + + if (buf_page_get_space(bpage) != id) { + /* Skip this block, as it does not belong to + the space that is being invalidated. */ + } else if (buf_page_get_io_fix(bpage) != BUF_IO_NONE) { + /* We cannot remove this page during this scan + yet; maybe the system is currently reading it + in, or flushing the modifications to the file */ + + all_freed = FALSE; + } else { + mutex_t* block_mutex = buf_page_get_mutex_enter(bpage); - if (buf_page_get_space(bpage) == id) { - if (bpage->buf_fix_count > 0 - || buf_page_get_io_fix(bpage) != BUF_IO_NONE) { + if (!block_mutex) { + /* It may be impossible case... + Something wrong, so will be scan_again */ + + all_freed = FALSE; + + goto next_page_no_mutex; + } + + if (bpage->buf_fix_count > 0) { /* We cannot remove this page during this scan yet; maybe the system is @@ -405,8 +423,40 @@ scan_again: (ulong) buf_page_get_page_no(bpage)); } #endif - if (buf_page_get_state(bpage) == BUF_BLOCK_FILE_PAGE - && ((buf_block_t*) bpage)->is_hashed) { + if (buf_page_get_state(bpage) != BUF_BLOCK_FILE_PAGE) { + /* This is a compressed-only block + descriptor. Ensure that prev_bpage + cannot be relocated when bpage is freed. */ + if (UNIV_LIKELY(prev_bpage != NULL)) { + switch (buf_page_get_state( + prev_bpage)) { + case BUF_BLOCK_FILE_PAGE: + /* Descriptors of uncompressed + blocks will not be relocated, + because we are holding the + buf_pool_mutex. */ + break; + case BUF_BLOCK_ZIP_PAGE: + case BUF_BLOCK_ZIP_DIRTY: + /* Descriptors of compressed- + only blocks can be relocated, + unless they are buffer-fixed. + Because both bpage and + prev_bpage are protected by + buf_pool_zip_mutex, it is + not necessary to acquire + further mutexes. */ + ut_ad(&buf_pool_zip_mutex + == block_mutex); + ut_ad(mutex_own(block_mutex)); + prev_bpage_buf_fix = TRUE; + prev_bpage->buf_fix_count++; + break; + default: + ut_error; + } + } + } else if (((buf_block_t*) bpage)->is_hashed) { ulint page_no; ulint zip_size; @@ -432,7 +482,8 @@ scan_again: buf_flush_remove(bpage); } - /* Remove from the LRU list */ + /* Remove from the LRU list. */ + if (buf_LRU_block_remove_hashed_page(bpage, TRUE) != BUF_BLOCK_ZIP_FREE) { buf_LRU_block_free_hashed_page((buf_block_t*) @@ -444,18 +495,27 @@ scan_again: ut_ad(block_mutex == &buf_pool_zip_mutex); ut_ad(!mutex_own(block_mutex)); - /* The compressed block descriptor - (bpage) has been deallocated and - block_mutex released. Also, - buf_buddy_free() may have relocated - prev_bpage. Rescan the LRU list. */ + if (prev_bpage_buf_fix) { + /* We temporarily buffer-fixed + prev_bpage, so that + buf_buddy_free() could not + relocate it, in case it was a + compressed-only block + descriptor. */ + + mutex_enter(block_mutex); + ut_ad(prev_bpage->buf_fix_count > 0); + prev_bpage->buf_fix_count--; + mutex_exit(block_mutex); + } - bpage = UT_LIST_GET_LAST(buf_pool->LRU); - continue; + goto next_page_no_mutex; } - } next_page: - mutex_exit(block_mutex); + mutex_exit(block_mutex); + } + +next_page_no_mutex: bpage = prev_bpage; } @@ -1425,7 +1485,12 @@ buf_LRU_free_block( ut_ad(buf_page_in_file(bpage)); //ut_ad(bpage->in_LRU_list); ut_ad(!bpage->in_flush_list == !bpage->oldest_modification); +#if UNIV_WORD_SIZE == 4 + /* On 32-bit systems, there is no padding in buf_page_t. On + other systems, Valgrind could complain about uninitialized pad + bytes. */ UNIV_MEM_ASSERT_RW(bpage, sizeof *bpage); +#endif if (!bpage->in_LRU_list || !block_mutex || !buf_page_can_relocate(bpage)) { @@ -1558,8 +1623,13 @@ not_freed: ut_ad(prev_b->in_LRU_list); ut_ad(buf_page_in_file(prev_b)); +#if UNIV_WORD_SIZE == 4 + /* On 32-bit systems, there is no + padding in buf_page_t. On other + systems, Valgrind could complain about + uninitialized pad bytes. */ UNIV_MEM_ASSERT_RW(prev_b, sizeof *prev_b); - +#endif UT_LIST_INSERT_AFTER(LRU, buf_pool->LRU, prev_b, b); @@ -1600,26 +1670,8 @@ not_freed: if (b->state == BUF_BLOCK_ZIP_PAGE) { buf_LRU_insert_zip_clean(b); } else { - buf_page_t* prev; - - ut_ad(b->in_flush_list); - ut_d(bpage->in_flush_list = FALSE); - - prev = UT_LIST_GET_PREV(flush_list, b); - UT_LIST_REMOVE(flush_list, buf_pool->flush_list, b); - - if (prev) { - ut_ad(prev->in_flush_list); - UT_LIST_INSERT_AFTER( - flush_list, - buf_pool->flush_list, - prev, b); - } else { - UT_LIST_ADD_FIRST( - flush_list, - buf_pool->flush_list, - b); - } + /* Relocate on buf_pool->flush_list. */ + buf_flush_relocate_on_flush_list(bpage, b); } mutex_exit(&flush_list_mutex); @@ -1792,7 +1844,12 @@ buf_LRU_block_remove_hashed_page( ut_a(buf_page_get_io_fix(bpage) == BUF_IO_NONE); ut_a(bpage->buf_fix_count == 0); +#if UNIV_WORD_SIZE == 4 + /* On 32-bit systems, there is no padding in + buf_page_t. On other systems, Valgrind could complain + about uninitialized pad bytes. */ UNIV_MEM_ASSERT_RW(bpage, sizeof *bpage); +#endif buf_LRU_remove_block(bpage); |