Hi Niyaz, Yes, you can use the -rankmap option to specify a full rank ordering. The syntax for rankmap string is: ``` /* rankmap string format (used in PMI_process_mapping) in ABNF: * * mapping = '(' format ',' (block / block_repeats) *[',' (block / block_repeats)] ')' * format = 'vector' * block = num / '(' num ',' num ',' num ')' * block_repeats = '[' block *[',' block] ']x' num * num = 1*DIGIT * * If a block is in 3-tuple of (X,Y,Z), the meaning is: * X - node id start value * Y - number of nodes with size Z * Z - number of processes assigned to each node * * If a block is a single number id, it denotes the node id, which is equivallen to * (id, 1, 1). * * A block_repeat repeats the bracketed block list by num of times. */ ``` What Joachim points out is that you can set a rank of 2, 3, 20, 30 if your total number of processes is 4. You can only order the processes. Hope that helps. -- Hui ________________________________ From: Niyaz Murshed via discuss <[email protected]> Sent: Monday, July 1, 2024 2:43 PM To: [email protected] <[email protected]>; Jenke, Joachim <[email protected]> Cc: Niyaz Murshed <[email protected]>; nd <[email protected]> Subject: Re: [mpich-discuss] Custom rank for processes Am actually trying to understand how/if I can pin a rank to a process .. also pin a core to a process. From: Niyaz Murshed via discuss <discuss@ mpich. org> Date: Monday, July 1, 2024 at 2: 34 PM To: Jenke, Joachim <jenke@ itc. rwth-aachen. de>, ZjQcmQRYFpfptBannerStart This Message Is From an External Sender This message came from outside your organization. ZjQcmQRYFpfptBannerEnd Am actually trying to understand how/if I can pin a rank to a process .. also pin a core to a process. From: Niyaz Murshed via discuss <[email protected]> Date: Monday, July 1, 2024 at 2:34 PM To: Jenke, Joachim <[email protected]>, [email protected] <[email protected]> Cc: Niyaz Murshed <[email protected]>, nd <[email protected]> Subject: Re: [mpich-discuss] Custom rank for processes What is the rankmap used for ? From: Jenke, Joachim <jenke@ itc. rwth-aachen. de> Sent: Monday, July 1, 2024 2: 21: 53 PM To: discuss@ mpich. org <discuss@ mpich. org> Cc: Niyaz Murshed <Niyaz. Murshed@ arm. com>; nd <nd@ arm. com> ZjQcmQRYFpfptBannerStart This Message Is From an External Sender This message came from outside your organization. ZjQcmQRYFpfptBannerEnd What is the rankmap used for ? ________________________________ From: Jenke, Joachim <[email protected]> Sent: Monday, July 1, 2024 2:21:53 PM To: [email protected] <[email protected]> Cc: Niyaz Murshed <[email protected]>; nd <[email protected]> Subject: Re: Custom rank for processes MPI defines rank numbers to be consecutive from 0 to size-1. Your suggested numbering will not work. -Joachim ________________________________ From: Niyaz Murshed via discuss <[email protected]> Sent: Monday, July 1, 2024 9:09:41 PM To: [email protected] <[email protected]> Cc: Niyaz Murshed <[email protected]>; nd <[email protected]> Subject: [mpich-discuss] Custom rank for processes Hello, Is it possible to provide custom ranks to processes ? I see a param called “-rankmap” .. Does it provide this option? Is it possible to do something like below : Node1 => 2 processes => rank 2,3 Node2 => 2 processes => rank ZjQcmQRYFpfptBannerStart This Message Is From an External Sender This message came from outside your organization. ZjQcmQRYFpfptBannerEnd Hello, Is it possible to provide custom ranks to processes ? I see a param called “-rankmap” .. Does it provide this option? Is it possible to do something like below : Node1 => 2 processes => rank 2,3 Node2 => 2 processes => rank 20,30 Thanks.