MDEV-31953 madvise(..., MADV_FREE) is causing a performance regression
buf_page_t::set_os_unused(): Remove the system call that had been added in
commit 16c9718758cb3bbff76672405d4ce1bce6da6c6f and revised in
commit c1fd082e9c7369f4511eb5a52e58cb15489caa74 for Microsoft Windows.
buf_pool_t::garbage_collect(): A new function to collect any garbage
from the InnoDB buffer pool that can be removed without writing any
log or data files. This will also invoke madvise() or
DiscardVirtualMemory() for all of buf_pool.free.
buf_resize_start(): If there is no actual change to
innodb_buffer_pool_size, invoke buf_pool_t::garbage_collect()
instead of starting buf_resize_callback() in another thread.
MDEV-32552 Write-ahead logging is broken for freed pages
buf_page_free(): Flag the freed page as modified if it is found in
the buffer pool.
buf_flush_page(): If the page has been freed, ensure that the log
for it has been durably written, before removing the page
from buf_pool.flush_list.
FindBlockX: Find also MTR_MEMO_PAGE_X_MODIFY in order to avoid an
occasional failure of innodb.innodb_defrag_concurrent, which involves
freeing and reallocating pages in the same mini-transaction.
This fixes a regression that was introduced in
commit a35b4ae89871d8184f04abb112c385481d557dbb (MDEV-15528).
This logic was tested by commenting out the $shutdown_timeout line
from a test and running the following:
A breakpoint in the modified buf_flush_page() was hit, and the
FIL_PAGE_LSN of that page had been last modified during the
mtr_t::commit() of a mini-transaction where buf_page_free()
had been executed on that page.
MDEV-32515 Use $MYSQLD_LAST_CMD in spider/bugfix.mdev_30370
$MYSQLD_CMD uses .1 as the defaults-group-suffix, which could cause
the use of the default port (3306) or socket, which will fail in
environment where these defaults are already in use by another server.
Adding an extra --defaults-group-suffix=.1.1 does not help, because
the first flag wins.
So we use $MYSQLD_LAST_CMD instead, which uses the correct suffix.
The extra innodb buffer pool warning is irrelevant to the goal of the
test (running --wsrep-recover with --plug-load-add=ha_spider should
not cause hang)
MDEV-32113: utf8mb3_key_col=utf8mb4_value cannot be used for ref
(Variant#3: Allow cross-charset comparisons, use a special
CHARSET_INFO to create lookup keys. Review input addressed.)
Equalities that compare utf8mb{3,4}_general_ci strings, like:
WHERE ... utf8mb3_key_col=utf8mb4_value (MB3-4-CMP)
can now be used to construct ref[const] access and also participate
in multiple-equalities.
This means that utf8mb3_key_col can be used for key-lookups when
compared with an utf8mb4 constant, field or expression using '=' or
'<=>' comparison operators.
This is controlled by optimizer_switch='cset_narrowing=on', which is
OFF by default.
IMPLEMENTATION
Item value comparison in (MB3-4-CMP) is done using utf8mb4_general_ci.
This is valid as any utf8mb3 value is also an utf8mb4 value.
When making index lookup value for utf8mb3_key_col, we do "Charset
Narrowing": characters that are in the Basic Multilingual Plane (=BMP) are
copied as-is, as they can be represented in utf8mb3. Characters that are
outside the BMP cannot be represented in utf8mb3 and are replaced
with U+FFFD, the "Replacement Character".
In utf8mb4_general_ci, the Replacement Character compares as equal to any
character that's not in BMP. Because of this, the constructed lookup value
will find all index records that would be considered equal by the original
condition (MB3-4-CMP).
MDEV-32476 LeakSanitizer errors in get_quick_select or Assertion ...
Problem was that JOIN_TAB::cleanup() was not run because
JOIN::top_join_tab_count was not set in case of early errors.
Fixed by setting JOIN::tab_join_tab_count when JOIN_TAB's are allocated.
Something that should eventually be fixed:
- Cleaning up JOIN_TAB's is now done in 3 different loops.
JOIN_TAB::cleanup() is only doing a partial cleanup. Other cleanups
are done outside of JOIN_TAB::cleanup().
The above should be fixed so that JOIN_TAB::cleanup() is freeing
everything related to it's own memory, including all its sub JOIN_ TAB's.
JOIN::cleanup() should only loop over all it's top JOIN_TAB's and call
JOIN_TAB::cleanup() on these.
This will greatly simplify and speedup the current code (as we now do some
cleanup's twice).
