pshpstuningguidew p040105.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, whic h is provided by C SM, you must u se 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