Details
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Bug
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Status: Closed (View Workflow)
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Blocker
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Resolution: Fixed
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10.5.4
Description
MDEV-22871 tried to optimize the buf_page_t initialization in buf_page_init_for_read() by initializing everything while the block is in freed state, and only afterwards attaching the block to buf_pool.page_hash.
In an rr replay trace, we have multiple threads executing in buf_page_optimistic_get() on the same buf_block_t while the block is being freed and reallocated several times in buf_page_init_for_read(). Because also the buf_page_t::id() is changing, the buf_pool.page_hash is being protected by a different rw-lock than the one that buf_page_optimistic_get() are successfully read-locking.
I think that the following fix should address this:
diff --git a/storage/innobase/buf/buf0buf.cc b/storage/innobase/buf/buf0buf.cc
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index 60979884fda..2cdd36a8b60 100644
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--- a/storage/innobase/buf/buf0buf.cc
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+++ b/storage/innobase/buf/buf0buf.cc
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@@ -3603,10 +3603,13 @@ buf_page_optimistic_get(
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return FALSE;
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}
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- page_hash_latch *hash_lock = buf_pool.hash_lock_get(block->page.id());
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+ const page_id_t id(block->page.id());
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+
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+ page_hash_latch *hash_lock = buf_pool.hash_lock_get(id);
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hash_lock->read_lock();
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- if (UNIV_UNLIKELY(block->page.state() != BUF_BLOCK_FILE_PAGE
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+ if (UNIV_UNLIKELY(id != block->page.id()
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+ || block->page.state() != BUF_BLOCK_FILE_PAGE
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|| block->page.io_fix() != BUF_IO_NONE)) {
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hash_lock->read_unlock();
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return(FALSE);
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@@ -3619,8 +3622,7 @@ buf_page_optimistic_get(
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buf_page_make_young_if_needed(&block->page);
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- ut_ad(!ibuf_inside(mtr)
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- || ibuf_page(block->page.id(), block->zip_size(), NULL));
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+ ut_ad(!ibuf_inside(mtr) || ibuf_page(id, block->zip_size(), NULL));
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mtr_memo_type_t fix_type;
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@@ -3633,6 +3635,8 @@ buf_page_optimistic_get(
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&block->lock, file, line);
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}
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+ ut_ad(id == block->page.id());
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+
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if (!success) {
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buf_block_buf_fix_dec(block);
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return(FALSE); |
Attachments
Issue Links
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- Closed
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