IBM pSeries User Manual download pdf (Page 14)

pshpstuningguidewp040105.doc Page 14

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 y|vmo -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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IBM pSeries User Manual Page 14