From b98c2cbb4ae038af46f3a5041ebaaa9f5ffbfee8 Mon Sep 17 00:00:00 2001
From: Davi Arnaut <Davi.Arnaut@Sun.COM>
Date: Wed, 1 Oct 2008 09:24:35 -0300
Subject: Bug#35164: Large number of invalid pthread_attr_setschedparam calls
Bug#37536: Thread scheduling causes performance degradation at low thread
count
Deprecated --skip-thread-priority startup option as newer versions of
the server won't change the thread priorities by default.
Giving threads different priorities might yield marginal improvements
in some platforms (where it actually works) but on the other hand it
might cause significant degradation depending on the thread count and
number of processors. Meddling with the thread priorities is a not a
safe bet as it is very dependent on the behavior of the cpu scheduler
and system where MySQL is being run.
From MySQL 6.0 and up the default behavior is that of not modifying
the threads priorities.
sql/mysqld.cc:
Deprecate --skip-thread-priority
---
sql/mysqld.cc | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
(limited to 'sql/mysqld.cc')
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index b04d4e3cecd..dcf1ee0188a 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -6223,7 +6223,7 @@ Can't be set to 1 if --log-slave-updates is used.",
{"skip-symlink", OPT_SKIP_SYMLINKS, "Don't allow symlinking of tables. Deprecated option. Use --skip-symbolic-links instead.",
0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
{"skip-thread-priority", OPT_SKIP_PRIOR,
- "Don't give threads different priorities.", 0, 0, 0, GET_NO_ARG, NO_ARG,
+ "Don't give threads different priorities. Deprecated option.", 0, 0, 0, GET_NO_ARG, NO_ARG,
DEFAULT_SKIP_THREAD_PRIORITY, 0, 0, 0, 0, 0},
#ifdef HAVE_REPLICATION
{"slave-load-tmpdir", OPT_SLAVE_LOAD_TMPDIR,
@@ -7865,6 +7865,9 @@ mysqld_get_one_option(int optid,
break;
case (int) OPT_SKIP_PRIOR:
opt_specialflag|= SPECIAL_NO_PRIOR;
+ sql_print_warning("The --skip-thread-priority startup option is deprecated "
+ "and will be removed in MySQL 7.0. MySQL 6.0 and up do not "
+ "give threads different priorities.");
break;
case (int) OPT_SKIP_LOCK:
opt_external_locking=0;
--
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