Enabling and Setting Huge Page Memory

Configure huge page memory to optimize memory usage and improve the translation lookaside buffer (TLB) hit rate.

After huge pages are set, they are exclusive to huge page programs, which occupy the memory. Therefore, manual management is required to allocate the huge page memory based on the memory usage of other applications.

1. Configure huge page memory in the database.
   1. Enable huge page memory.

      In the OBServer configuration, set use_large_pages to true to instruct the database to use huge pages.

      alter system set use_large_pages = "true";

   2. Restart OBServer to make the configuration take effect.
   3. Check whether huge page memory is enabled.

      SHOW PARAMETERS LIKE 'use_large_pages';

      In the command output, if the value of use_large_pages is true, huge page memory has been enabled for OBServer.

2. Configure huge page memory in the OS.
   1. Check the huge page size supported by the OS.

      cat /proc/meminfo |grep Huge

      Here, the huge page size supported by the current OS is 2,048 KB.

      

   2. Configure the number of huge pages. In this example, the number of huge pages to be allocated is 256,000.

      echo 256000 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages 

      The preceding command requests the OS to allocate 256,000 2,048 KB huge pages to applications.