Huge Pages for Informix on SPARC Solaris

To get hugh pages for Informix on Solaris

1. Set RESIDENT to a value other than 0, >0 means the first N shared memory segments will be pinned in memory.

https://informixdba.wordpress.com/2013/03/08/huge-pages/

2. Make sure IFX_LARGE_PAGES is not set to 0.

http://www-01.ibm.com/support/knowledgecenter/SSGU8G_12.1.0/com.ibm.sqlr.doc/ids_sqr_404.htm

3. To get pages >4MB in size the hardware must have support for 2GB pages, run pagesize -a to check what the hardware supports

https://blogs.oracle.com/mandalika/entry/enabling_2_gb_large_pages

4,  Either use ppgsz or mpss.so.1

The three ways to change the default page size for an application are:

• Use the Oracle Solaris OS command ppgsz(1).
• Compile the application with the -xpagesize, -xpagesize_heap, and -xpagesize_stack options. See the compiler man pages for details.
• Use MPSS specific environment variables. See the mpss.so.1(1) man page for details.

http://docs.oracle.com/cd/E24457_01/html/E21996/aewda.html

ppgsz is documented at

https://docs.oracle.com/cd/E19683-01/816-0210/6m6nb7mht/index.html

mpss.so.1 is documented at

http://docs.oracle.com/cd/E19253-01/816-5165/6mbb0m9lf/index.html

5. Note

“Solaris has had large parges for many years. Initially, a large page on SPARC was 4MB. Then, much later, Solaris 9 added new APIs for Multiple Page Size Support. At that time, the maximum supported by hardware was 256MB. Today, the T4 processor supports page sizes up to 2GB.”

https://www.linkedin.com/groups/Solaris-Huge-pages-60651.S.78812448

6. UltraSPARC II/III/III+/IV/IV+ and UltraSPARC T1 (aka Niagara) only support large pages of 4MB

http://www.solarisinternals.com/wiki/index.php/Multiple_Page_Size_Support#Default_page_sizes.2C_and_tunables_on_different_platforms

7. Check none of these to disable large pages are being used

https://blogs.oracle.com/mandalika/entry/solaris_disabling_out_of_the

• set exec_lpg_disable = 1This parameter prevents large pages from being used when the kernel is allocating memory for processes being executed. These constitute the memory needed for a processes’ text/data/bss.
• set use_brk_lpg = 0This parameter prevents large pages from being used for heap. To enable large pages for heap, set the value of this parameter to 1 or remove this parameter from /etc/system completely.

  Note:
  brk() is the kernel routine that is called whenever a user level application invokes malloc().

• set use_stk_lpg = 0This parameter disables the large pages for stack. Set it to 1 to retain the default functionality.
• set use_zmap_lpg = 0This variable controls the size of anonymous (anon) pages.
• set use_text_pgsz4m = 0This tunable disables the default use of 4M text pages on UltraSPARC-III/III+/IV/IV+/T1 platforms.
• set use_text_pgsz64k = 0This tunable disables the default use of 64K text pages on UltraSPARC-T1 (Niagara) platform.
• set use_initdata_pgsz64k = 0This tunable disables the default use of 64K data pages on UltraSPARC-T1 (Niagara) platform.

8.The T4 processor was the first to add “Support for a much larger Memory Management Unit page size (2GB)”

Click to access o11-090-sparc-t4-arch-496245.pdf

https://blogs.oracle.com/mandalika/entry/enabling_2_gb_large_pages

“Prerequisites:

OS: Solaris 10 8/11 (Update 10) or later
Hardware: SPARC T4. eg., SPARC T4-1, T4-2 or T4-4”