IBM pSeries manual Pshpstuningguidewp040105.doc

adapter is configured. The volume of reservation is proportional to the number of user windows configured on the HPS adapter. A private window is required for each MPI task.

Here is a formula to calculate the number of TLPs needed by the HPS adapter. In the formula below, number_of_sni refers to the number of sniX logical interfaces present in the partition. To obtain the num_windows, send pool size, and receive pool size values for the AIX partition, run the following command:

lsattr -El sniX (where X is the device minor number: 0, 1, 2, etc.)

total_num_windows = num_windows + 7

number of TLP required = A + B + C + D

where:

A= 1 + (number_of_sni * 2)

B= (number_of_sni * total_num_windows)

C= (number_of_sni * total_num_windows * 262144) / 16777216

D= (send pool size + receive pool size) / 16777216

To change the number of windows, use the chgsni command.

To set the Large Page option, use one of the following vmo commands:

•vmo -r -o v_pinshm=1 -o lgpg_size=16777216 -o lgpg_regions= <number of TLP required>

•dsh -vn <node name> "echo yvmo -r -o v_pinshm=1 -o lgpg_size=16777216 -o lgpg_regions = <number of TLP required>"

If you use dsh command, which is provided by CSM, you must use the echo command, because vmo asks for verification to run bosboot.

Here is a sample of the information returned from the vmo command.

>Setting v_pinshm to 1 in nextboot file

>Setting lgpg_size to 16777216 in nextboot file

>Setting lgpg_regions to the required number of TLP in nextboot file

>Warning: some changes will take effect only after a bosboot and a reboot

>Run bosboot now?

>A previous bosdebug command has changed characteristics of this boot image. Use bosdebug -L to display

what these changes are.

>bosboot: Boot image is 19877 512 byte blocks.

>Warning: changes will take effect only at next reboot

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