Commit 409e8843 authored by Sergey Vojtovich's avatar Sergey Vojtovich

Applying InnoDB snapshot, fixes BUG#35077.

Detailed revision comments:

r6548 | marko | 2010-02-03 15:01:39 +0200 (Wed, 03 Feb 2010) | 11 lines
branches/zip: buf_LRU_invalidate_tablespace(): Ensure that prev_bpage
is not relocated when freeing a compressed block.  This avoids the
costly rescan of the LRU list.  (Bug #35077, Issue #449)

At most one buffer-fix will be active at a time, affecting two blocks:
the buf_page_t and the compressed page frame. This should not block
the memory defragmentation in buf0buddy.c too much.  In fact, it may
avoid unnecessary copying if also prev_bpage belongs to the tablespace
that is being invalidated.

rb://240
parent 101d6a09
2010-02-03 The InnoDB Team
* buf/buf0lru.c:
Fix Bug#35077 Very slow DROP TABLE (ALTER TABLE, OPTIMIZE TABLE)
on compressed tables
2010-02-03 The InnoDB Team
* handler/ha_innodb.cc, include/row0mysql.h, row/row0mysql.c:
......
......@@ -347,11 +347,11 @@ scan_again:
all_freed = TRUE;
rescan:
bpage = UT_LIST_GET_LAST(buf_pool->LRU);
while (bpage != NULL) {
buf_page_t* prev_bpage;
ibool prev_bpage_buf_fix = FALSE;
ut_a(buf_page_in_file(bpage));
......@@ -394,8 +394,40 @@ rescan:
(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;
......@@ -419,7 +451,8 @@ rescan:
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*)
......@@ -431,18 +464,27 @@ rescan:
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);
}
goto rescan;
goto next_page_no_mutex;
}
next_page:
mutex_exit(block_mutex);
}
next_page_no_mutex:
bpage = prev_bpage;
}
......
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