MDEV-26193: Wake up purge less often

Starting with commit 6e12ebd4a748eba738e08ad1d7f5dec782ff63ee
(MDEV-25062), srv_wake_purge_thread_if_not_active() became
more expensive operation, especially on NUMA systems, because
instead of reading an atomic global variable trx_sys.rseg_history_len
we are traversing up to 128 cache lines in trx_sys.history_exists().

trx_t::commit_cleanup(): Do not wake up purge at all.
We will wake up purge about once per second in srv_master_callback().

srv_master_do_active_tasks(), srv_master_do_idle_tasks():
Move some duplicated code to srv_master_callback().

srv_master_callback(): Invoke purge_coordinator_timer_callback()
to ensure that purge will be periodically woken up, even if the
latest execution of trx_t::commit_cleanup() allowed the purge view
to advance but did not wake up purge.
Do not call log_free_check(), because every thread that is going
to generate redo log is supposed to call that function anyway,
before acquiring any page latches. Additional calls to the function
every few seconds should not make any difference.

srv_shutdown_threads(): Ensure that srv_shutdown_state can be at most
SRV_SHUTDOWN_INITIATED in srv_master_callback(), by first invoking
srv_master_timer.reset() before changing srv_shutdown_state.
(Note: We first terminate the srv_master_callback and only then
terminate the purge tasks. Thus, the purge subsystem should exist
when srv_master_callback() invokes purge_coordinator_timer_callback()
if it was initiated in the first place.

1 files changed, 1 insertions, 1 deletions

diff --git a/storage/innobase/srv/srv0start.cc b/storage/innobase/srv/srv0start.cc
index bac9a3b25b5..3f0ccf44b1e 100644
--- a/storage/innobase/srv/srv0start.cc
+++ b/storage/innobase/srv/srv0start.cc
@@ -812,9 +812,9 @@ srv_open_tmp_tablespace(bool create_new_db)
 static void srv_shutdown_threads()
 {
 	ut_ad(!srv_undo_sources);
-	srv_shutdown_state = SRV_SHUTDOWN_EXIT_THREADS;
 	ut_d(srv_master_thread_enable());
 	srv_master_timer.reset();
+	srv_shutdown_state = SRV_SHUTDOWN_EXIT_THREADS;
 
 	if (purge_sys.enabled()) {
 		srv_purge_shutdown();