List:Commits« Previous MessageNext Message »
From:Davi Arnaut Date:September 30 2008 6:12pm
Subject:bzr commit into mysql-5.1 branch (davi:2746) Bug#35164 Bug#37536
View as plain text  
# At a local mysql-5.1 repository of davi

 2746 Davi Arnaut	2008-09-30
      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 version 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.
modified:
  sql/mysqld.cc

=== modified file 'sql/mysqld.cc'
--- a/sql/mysqld.cc	2008-08-26 09:31:17 +0000
+++ b/sql/mysqld.cc	2008-09-30 18:12:27 +0000
@@ -6229,7 +6229,7 @@ Can't be set to 1 if --log-slave-updates
   {"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,
@@ -7871,6 +7871,9 @@ 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;

Thread
bzr commit into mysql-5.1 branch (davi:2746) Bug#35164 Bug#37536Davi Arnaut30 Sep
  • Re: bzr commit into mysql-5.1 branch (davi:2746) Bug#35164 Bug#37536Konstantin Osipov30 Sep