~ignacio-nin/percona-server/5.1-issue26684

# name       : innodb_thread_concurrency_timer_based.patch

# introduced : 11 or before

# maintainer : Yasufumi

#

#!!! notice !!!

# Any small change to this file in the main branch

# should be done or reviewed by the maintainer!

diff -ruN a/storage/innodb_plugin/handler/ha_innodb.cc b/storage/innodb_plugin/handler/ha_innodb.cc

--- a/storage/innodb_plugin/handler/ha_innodb.cc	2010-04-29 16:43:16.000000000 +0900

+++ b/storage/innodb_plugin/handler/ha_innodb.cc	2010-04-29 16:43:53.000000000 +0900

@@ -151,6 +151,7 @@

 static ulong innobase_read_io_threads;

 static ulong innobase_write_io_threads;

+static my_bool innobase_thread_concurrency_timer_based;

 static long long innobase_buffer_pool_size, innobase_log_file_size;

 /** Percentage of the buffer pool to reserve for 'old' blocks.

@@ -2341,6 +2342,9 @@

 	srv_n_log_files = (ulint) innobase_log_files_in_group;

 	srv_log_file_size = (ulint) innobase_log_file_size;

+	srv_thread_concurrency_timer_based =

+		(ibool) innobase_thread_concurrency_timer_based;

+

 #ifdef UNIV_LOG_ARCHIVE

 	srv_log_archive_on = (ulint) innobase_log_archive;

 #endif /* UNIV_LOG_ARCHIVE */

@@ -11216,6 +11220,12 @@

   "Maximum delay between polling for a spin lock (6 by default)",

   NULL, NULL, 6L, 0L, ~0L, 0);

+static MYSQL_SYSVAR_BOOL(thread_concurrency_timer_based,

+  innobase_thread_concurrency_timer_based,

+  PLUGIN_VAR_NOCMDARG | PLUGIN_VAR_READONLY,

+  "Use InnoDB timer based concurrency throttling. ",

+  NULL, NULL, FALSE);

+

 static MYSQL_SYSVAR_ULONG(thread_concurrency, srv_thread_concurrency,

   PLUGIN_VAR_RQCMDARG,

   "Helps in performance tuning in heavily concurrent environments. Sets the maximum number of threads allowed inside InnoDB. Value 0 will disable the thread throttling.",

@@ -11432,6 +11442,7 @@

   MYSQL_SYSVAR(spin_wait_delay),

   MYSQL_SYSVAR(table_locks),

   MYSQL_SYSVAR(thread_concurrency),

+  MYSQL_SYSVAR(thread_concurrency_timer_based),

   MYSQL_SYSVAR(thread_sleep_delay),

   MYSQL_SYSVAR(autoinc_lock_mode),

   MYSQL_SYSVAR(show_verbose_locks),

diff -ruN a/storage/innodb_plugin/handler/innodb_patch_info.h b/storage/innodb_plugin/handler/innodb_patch_info.h

--- a/storage/innodb_plugin/handler/innodb_patch_info.h	2010-04-29 16:43:16.000000000 +0900

+++ b/storage/innodb_plugin/handler/innodb_patch_info.h	2010-04-29 16:43:53.000000000 +0900

@@ -31,5 +31,6 @@

 {"innodb_expand_undo_slots","expandable maximum number of undo slots","from 1024 (default) to about 4000","http://www.percona.com/docs/wiki/percona-xtradb"},

 {"innodb_extra_rseg","allow to create extra rollback segments","When create new db, the new parameter allows to create more rollback segments","http://www.percona.com/docs/wiki/percona-xtradb"},

 {"innodb_overwrite_relay_log_info","overwrite relay-log.info when slave recovery","Building as plugin, it is not used.","http://www.percona.com/docs/wiki/percona-xtradb:innodb_overwrite_relay_log_info"},

+{"innodb_thread_concurrency_timer_based","use InnoDB timer based concurrency throttling (backport from MySQL 5.4.0)","",""},

 {NULL, NULL, NULL, NULL}

 };

diff -ruN a/storage/innodb_plugin/include/srv0srv.h b/storage/innodb_plugin/include/srv0srv.h

--- a/storage/innodb_plugin/include/srv0srv.h	2010-04-29 16:39:34.000000000 +0900

+++ b/storage/innodb_plugin/include/srv0srv.h	2010-04-29 16:43:53.000000000 +0900

@@ -147,6 +147,8 @@

 extern ulint	srv_mem_pool_size;

 extern ulint	srv_lock_table_size;

+extern ibool	srv_thread_concurrency_timer_based;

+

 extern ulint	srv_n_file_io_threads;

 extern ulong	srv_read_ahead_threshold;

 extern ulint	srv_n_read_io_threads;

diff -ruN a/storage/innodb_plugin/srv/srv0srv.c b/storage/innodb_plugin/srv/srv0srv.c

--- a/storage/innodb_plugin/srv/srv0srv.c	2010-04-29 16:39:34.000000000 +0900

+++ b/storage/innodb_plugin/srv/srv0srv.c	2010-04-29 16:43:53.000000000 +0900

@@ -318,6 +318,7 @@

 computer. Bigger computers need bigger values. Value 0 will disable the

 concurrency check. */

+UNIV_INTERN ibool	srv_thread_concurrency_timer_based = FALSE;

 UNIV_INTERN ulong	srv_thread_concurrency	= 0;

 /* this mutex protects srv_conc data structures */

@@ -1069,6 +1070,75 @@

 /*********************************************************************//**

 Puts an OS thread to wait if there are too many concurrent threads

 (>= srv_thread_concurrency) inside InnoDB. The threads wait in a FIFO queue. */

+

+#ifdef HAVE_ATOMIC_BUILTINS

+static void

+enter_innodb_with_tickets(trx_t* trx)

+{

+	trx->declared_to_be_inside_innodb = TRUE;

+	trx->n_tickets_to_enter_innodb = SRV_FREE_TICKETS_TO_ENTER;

+	return;

+}

+

+static void

+srv_conc_enter_innodb_timer_based(trx_t* trx)

+{

+	lint	conc_n_threads;

+	ibool	has_yielded = FALSE;

+	ulint	has_slept = 0;

+

+	if (trx->declared_to_be_inside_innodb) {

+		ut_print_timestamp(stderr);

+		fputs(

+"  InnoDB: Error: trying to declare trx to enter InnoDB, but\n"

+"InnoDB: it already is declared.\n", stderr);

+		trx_print(stderr, trx, 0);

+		putc('\n', stderr);

+	}

+retry:

+	if (srv_conc_n_threads < (lint) srv_thread_concurrency) {

+		conc_n_threads = os_atomic_increment_lint(&srv_conc_n_threads, 1);

+		if (conc_n_threads <= (lint) srv_thread_concurrency) {

+			enter_innodb_with_tickets(trx);

+			return;

+		}

+		os_atomic_increment_lint(&srv_conc_n_threads, -1);

+	}

+	if (!has_yielded)

+	{

+		has_yielded = TRUE;

+		os_thread_yield();

+		goto retry;

+	}

+	if (trx->has_search_latch

+	    || NULL != UT_LIST_GET_FIRST(trx->trx_locks)) {

+

+		conc_n_threads = os_atomic_increment_lint(&srv_conc_n_threads, 1);

+		enter_innodb_with_tickets(trx);

+		return;

+	}

+	if (has_slept < 2)

+	{

+		trx->op_info = "sleeping before entering InnoDB";

+		os_thread_sleep(10000);

+		trx->op_info = "";

+		has_slept++;

+	}

+	conc_n_threads = os_atomic_increment_lint(&srv_conc_n_threads, 1);

+	enter_innodb_with_tickets(trx);

+	return;

+}

+

+static void

+srv_conc_exit_innodb_timer_based(trx_t* trx)

+{

+	os_atomic_increment_lint(&srv_conc_n_threads, -1);

+	trx->declared_to_be_inside_innodb = FALSE;

+	trx->n_tickets_to_enter_innodb = 0;

+	return;

+}

+#endif

+

 UNIV_INTERN

 void

 srv_conc_enter_innodb(

@@ -1099,6 +1169,13 @@

 		return;

 	}

+#ifdef HAVE_ATOMIC_BUILTINS

+	if (srv_thread_concurrency_timer_based) {

+		srv_conc_enter_innodb_timer_based(trx);

+		return;

+	}

+#endif

+

 	os_fast_mutex_lock(&srv_conc_mutex);

 retry:

 	if (trx->declared_to_be_inside_innodb) {

@@ -1242,6 +1319,14 @@

 	}

 	ut_ad(srv_conc_n_threads >= 0);

+#ifdef HAVE_ATOMIC_BUILTINS

+	if (srv_thread_concurrency_timer_based) {

+		os_atomic_increment_lint(&srv_conc_n_threads, 1);

+		trx->declared_to_be_inside_innodb = TRUE;

+		trx->n_tickets_to_enter_innodb = 1;

+		return;

+	}

+#endif

 	os_fast_mutex_lock(&srv_conc_mutex);

@@ -1275,6 +1360,13 @@

 		return;

 	}

+#ifdef HAVE_ATOMIC_BUILTINS

+	if (srv_thread_concurrency_timer_based) {

+		srv_conc_exit_innodb_timer_based(trx);

+		return;

+	}

+#endif

+

 	os_fast_mutex_lock(&srv_conc_mutex);

 	ut_ad(srv_conc_n_threads > 0);