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MDEV-31343 Another server hang with innodb_undo_log_truncate=ON

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trx_purge_truncate_history(): While waiting for a write-fixed block
to become available, simply wait for an exclusive latch on it.
Also, simplify the iteration: first check for oldest_modification>2
(to ignore clean pages or pages belonging to the temporary tablespace)
and then compare the tablespace identifier.

Before releasing buf_pool.flush_list_mutex we will buffer-fix the block
of interest. In that way, buf_page_t::can_relocate() will not hold on
the block and it must remain in the buffer pool until we have acquired
an exclusive latch on it. If the block is still dirty, we will register
it with the tablespace truncation mini-transaction; else, we will simply
release the latch and buffer-fix and move to the next block.

This also reverts commit c4d7939989
because that fix should no longer be necessary; the wait for an
exclusive block latch should allow buf_pool_t::release_freed_page()
on the same block to proceed.

Tested by: Axel Schwenke, Matthias Leich
This commit is contained in:
Marko Mäkelä
2023-05-26 16:16:10 +03:00
parent 03a9366c73
commit db8765500e
1 changed files with 22 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
storage/innobase/trx/trx0purge.cc
View File

@@ -685,6 +685,7 @@ not_free:
mtr_t mtr;
mtr.start();
mtr.x_lock_space(&space);
const auto space_id= space.id;
/* Lock all modified pages of the tablespace.
@@ -694,8 +695,8 @@ not_free:
mini-transaction commit and the server was killed, then
discarding the to-be-trimmed pages without flushing would
break crash recovery. */
rescan:
mysql_mutex_lock(&buf_pool.flush_list_mutex);
for (buf_page_t *bpage= UT_LIST_GET_LAST(buf_pool.flush_list); bpage; )
{
ut_ad(bpage->oldest_modification());
@@ -703,46 +704,47 @@ not_free:
buf_page_t *prev= UT_LIST_GET_PREV(list, bpage);
if (bpage->id().space() == space.id &&
bpage->oldest_modification() != 1)
if (bpage->oldest_modification() > 2 && bpage->id().space() == space_id)
{
ut_ad(bpage->frame);
auto block= reinterpret_cast<buf_block_t*>(bpage);
if (!bpage->lock.x_lock_try())
bpage->fix();
{
rescan:
/* Let buf_pool_t::release_freed_page() proceed. */
/* Try to acquire an exclusive latch while the cache line is
fresh after fix(). */
const bool got_lock{bpage->lock.x_lock_try()};
buf_pool.flush_hp.set(prev);
mysql_mutex_unlock(&buf_pool.flush_list_mutex);
mysql_mutex_lock(&buf_pool.mutex);
mysql_mutex_lock(&buf_pool.flush_list_mutex);
mysql_mutex_unlock(&buf_pool.mutex);
bpage= UT_LIST_GET_LAST(buf_pool.flush_list);
continue;
if (!got_lock)
bpage->lock.x_lock();
}
buf_pool.flush_hp.set(prev);
mysql_mutex_unlock(&buf_pool.flush_list_mutex);
#ifdef BTR_CUR_HASH_ADAPT
ut_ad(!block->index); /* There is no AHI on undo tablespaces. */
/* There is no AHI on undo tablespaces. */
ut_ad(!reinterpret_cast<buf_block_t*>(bpage)->index);
#endif
bpage->fix();
ut_ad(!bpage->is_io_fixed());
mysql_mutex_lock(&buf_pool.flush_list_mutex);
ut_ad(bpage->id().space() == space_id);
if (bpage->oldest_modification() > 1)
if (bpage->oldest_modification() > 2)
{
mtr.memo_push(reinterpret_cast<buf_block_t*>(bpage),
MTR_MEMO_PAGE_X_FIX);
mysql_mutex_lock(&buf_pool.flush_list_mutex);
ut_ad(bpage->oldest_modification() > 2);
bpage->reset_oldest_modification();
mtr.memo_push(block, MTR_MEMO_PAGE_X_FIX);
}
else
{
bpage->unfix();
bpage->lock.x_unlock();
mysql_mutex_lock(&buf_pool.flush_list_mutex);
}
if (prev != buf_pool.flush_hp.get())
/* Rescan, because we may have lost the position. */
{
mysql_mutex_unlock(&buf_pool.flush_list_mutex);
goto rescan;
}
}
bpage= prev;