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Re: innodb memory usage vs swap
Posted by: Rick James ()
Date: September 10, 2010 11:14PM

I asked about huge pages because you mentioned
vm.nr_hugepages = 2048

cat /proc/meminfo |grep Hugepagesize
That might say 2048K

Multiply those together and you get 4GB reserved for huge pages.

mysqld is probably not running --large-pages
Quote

Large page support in MySQL is disabled by default. To enable it, start the server with the --large-pages option. For example, you can use the following lines in your server's my.cnf file:

[mysqld]
large-pages

A guess: The OS preallocated 4GB for huge pages. But no process is using it. Meanwhile the other 4GB is used by mysqld and assorted OS things. But mysqld needs 4GB for the innodb_buffer_pool. So, something has to swap.

See also http://bugs.mysql.com/bug.php?id=43606
http://dev.mysql.com/doc/refman/5.0/en/large-page-support.html

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Subject Views Written By Posted
innodb memory usage vs swap 5890 kevin foote 09/08/2010 10:35PM
Re: innodb memory usage vs swap 1906 Rick James 09/10/2010 12:01AM
Re: innodb memory usage vs swap 3596 kevin foote 09/10/2010 09:44AM
Re: innodb memory usage vs swap 1853 kevin foote 09/10/2010 09:59AM
Re: innodb memory usage vs swap 1948 kevin foote 09/10/2010 12:26PM
Re: innodb memory usage vs swap 4669 Rick James 09/10/2010 11:14PM
Re: innodb memory usage vs swap 2520 kevin foote 09/14/2010 08:42AM
Re: innodb memory usage vs swap 1887 kevin foote 09/14/2010 09:44AM
Re: innodb memory usage vs swap 1907 Rick James 09/14/2010 08:12PM


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