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Pinning problem on Intel MPI 2021.11

hakostra1
New Contributor II
‎01-05-2024 04:39 AM
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I have a workstation with Ubuntu 22.04 running the 6.5.0-14-generic kernel and an Intel Core i9-13900K processor. This processor has 8 P-cores and 16 E-cores.

I have a CFD application, and my experience is that running on the 8 P-cores are about as fast as running on all 24 cores together.

With Intel MPI 2021.7.1 I set the environment variable I_MPI_PIN_PROCESSOR_LIST="0,2,4,6,8,10,12,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31". This means that when I run on only 8 cores, the 8 physical cores corresponding to the P-cores were used, and when I decided to run on 24 cores, all the physical cores was used.

With Intel MPI 2021.7.1 setting I_MPI_DEBUG=5 I got a confirmation on the terminal that the pinning was indeed working:

[0] MPI startup(): Intel(R) MPI Library, Version 2021.7  Build 20221022 (id: f7b29a2495)
[0] MPI startup(): Copyright (C) 2003-2022 Intel Corporation.  All rights reserved.
[0] MPI startup(): library kind: release
[0] MPI startup(): libfabric version: 1.13.2rc1-impi
[0] MPI startup(): libfabric provider: tcp;ofi_rxm
[0] MPI startup(): File "/home/hakostra/KMT/mglet-8.6.2+40-g87906f9/IntelMPI/etc/tuning_skx_shm-ofi_tcp-ofi-rxm_10.dat" not found
[0] MPI startup(): Load tuning file: "/home/hakostra/KMT/mglet-8.6.2+40-g87906f9/IntelMPI/etc/tuning_skx_shm-ofi_tcp-ofi-rxm.dat"
[0] MPI startup(): Rank    Pid      Node name  Pin cpu
[0] MPI startup(): 0       731216   kmt-trd2   0
[0] MPI startup(): 1       731217   kmt-trd2   2
[0] MPI startup(): 2       731218   kmt-trd2   4
[0] MPI startup(): 3       731219   kmt-trd2   6
[0] MPI startup(): 4       731220   kmt-trd2   8
[0] MPI startup(): 5       731221   kmt-trd2   10
[0] MPI startup(): 6       731222   kmt-trd2   12
[0] MPI startup(): 7       731223   kmt-trd2   14
[0] MPI startup(): I_MPI_ROOT=/home/hakostra/KMT/mglet-8.6.2+40-g87906f9/IntelMPI
[0] MPI startup(): I_MPI_MPIRUN=mpirun
[0] MPI startup(): I_MPI_HYDRA_TOPOLIB=hwloc
[0] MPI startup(): I_MPI_PIN_PROCESSOR_LIST=0,2,4,6,8,10,12,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
[0] MPI startup(): I_MPI_INTERNAL_MEM_POLICY=default
[0] MPI startup(): I_MPI_DEBUG=5

However, now trying Intel MPI 2021.11 (as part of the oneAPI 2024.0 toolkits), when I set the same, I get:

[0] MPI startup(): Intel(R) MPI Library, Version 2021.11  Build 20231005 (id: 74c4a23)
[0] MPI startup(): Copyright (C) 2003-2023 Intel Corporation.  All rights reserved.
[0] MPI startup(): library kind: release
[0] MPI startup(): File "" not found
[0] MPI startup(): Load tuning file: "/home/hakostra/KMT/el-8/IntelMPI/opt/mpi/etc/tuning_skx_shm.dat"
[0] MPI startup(): Rank    Pid      Node name  Pin cpu
[0] MPI startup(): 0       738139   kmt-trd2   0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
[0] MPI startup(): 1       738140   kmt-trd2   0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
[0] MPI startup(): 2       738141   kmt-trd2   0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
[0] MPI startup(): 3       738142   kmt-trd2   0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
[0] MPI startup(): 4       738143   kmt-trd2   0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
[0] MPI startup(): 5       738144   kmt-trd2   0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
[0] MPI startup(): 6       738145   kmt-trd2   0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
[0] MPI startup(): 7       738146   kmt-trd2   0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
[0] MPI startup(): I_MPI_ROOT=/home/hakostra/KMT/el-8/IntelMPI
[0] MPI startup(): I_MPI_MPIRUN=mpirun
[0] MPI startup(): I_MPI_BIND_WIN_ALLOCATE=localalloc
[0] MPI startup(): I_MPI_HYDRA_TOPOLIB=hwloc
[0] MPI startup(): I_MPI_RETURN_WIN_MEM_NUMA=-1
[0] MPI startup(): I_MPI_PIN=1
[0] MPI startup(): I_MPI_PIN_PROCESSOR_LIST=0,2,4,6,8,10,12,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
[0] MPI startup(): I_MPI_PIN_RESPECT_CPUSET=0
[0] MPI startup(): I_MPI_PIN_RESPECT_HCA=0
[0] MPI startup(): I_MPI_INTERNAL_MEM_POLICY=default
[0] MPI startup(): I_MPI_FABRICS=shm
[0] MPI startup(): I_MPI_DEBUG=5

I.e. it seems that the pinning is not applied properly.

I have tried a number of different variables (I_MPI_PIN_RESPECT_CPUSET=0,I_MPI_PIN_RESPECT_HCA=0), and none of them seems to affect the pinning at all.

Does anyone have an advice or insight in the issue?

Thanks in advance.

 

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TobiasK
Moderator
‎01-11-2024 05:05 AM
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@hakostra1 
Could you please try to set:

I_MPI_PIN=1 I_MPI_PIN_CELL=core I_MPI_PIN_DOMAIN=1 I_MPI_PIN_ORDER=compact

instead of defining I_MPI_PIN_PROCESSOR_LIST?

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hakostra1
New Contributor II
‎01-11-2024 05:13 AM
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In response to TobiasK

Does not appear to be working:

[0] MPI startup(): Intel(R) MPI Library, Version 2021.11  Build 20231005 (id: 74c4a23)
[0] MPI startup(): Copyright (C) 2003-2023 Intel Corporation.  All rights reserved.
[0] MPI startup(): library kind: release
[0] MPI startup(): libfabric version: 1.18.1-impi
[0] MPI startup(): libfabric provider: tcp
[0] MPI startup(): File "" not found
[0] MPI startup(): Load tuning file: "/home/hakostra/KMT/el-8/IntelMPI/opt/mpi/etc/tuning_skx_shm-ofi.dat"
[0] MPI startup(): ===== Nic pinning on kmt-trd2 =====
[0] MPI startup(): Rank	Pin nic
[0] MPI startup(): 0	enp9s0f0
[0] MPI startup(): 1	enp9s0f0
[0] MPI startup(): 2	enp9s0f0
[0] MPI startup(): 3	enp9s0f0
[0] MPI startup(): 4	enp9s0f0
[0] MPI startup(): 5	enp9s0f0
[0] MPI startup(): 6	enp9s0f0
[0] MPI startup(): 7	enp9s0f0
[0] MPI startup(): Rank    Pid      Node name  Pin cpu
[0] MPI startup(): 0       1164811  kmt-trd2   {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,
                                 30,31}
[0] MPI startup(): 1       1164812  kmt-trd2   {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,
                                 30,31}
[0] MPI startup(): 2       1164813  kmt-trd2   {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,
                                 30,31}
[0] MPI startup(): 3       1164814  kmt-trd2   {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,
                                 30,31}
[0] MPI startup(): 4       1164815  kmt-trd2   {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,
                                 30,31}
[0] MPI startup(): 5       1164816  kmt-trd2   {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,
                                 30,31}
[0] MPI startup(): 6       1164817  kmt-trd2   {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,
                                 30,31}
[0] MPI startup(): 7       1164818  kmt-trd2   {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,
                                 30,31}
[0] MPI startup(): I_MPI_ROOT=/home/hakostra/KMT/el-8/IntelMPI
[0] MPI startup(): I_MPI_MPIRUN=mpirun
[0] MPI startup(): I_MPI_BIND_WIN_ALLOCATE=localalloc
[0] MPI startup(): I_MPI_HYDRA_TOPOLIB=hwloc
[0] MPI startup(): I_MPI_RETURN_WIN_MEM_NUMA=-1
[0] MPI startup(): I_MPI_PIN=1
[0] MPI startup(): I_MPI_PIN_CELL=core
[0] MPI startup(): I_MPI_PIN_DOMAIN=1
[0] MPI startup(): I_MPI_PIN_ORDER=compact
[0] MPI startup(): I_MPI_INTERNAL_MEM_POLICY=default
[0] MPI startup(): I_MPI_DEBUG=5

The only apparent difference is that now there are additional curly brackets { } around the pinned core list..

 

And here is the output of the cpuinfo tool:

cpuinfo 
Intel(R) processor family information utility, Version 2021.11 Build 20231005 (id: 74c4a23)
Copyright (C) 2005-2023 Intel Corporation.  All rights reserved.

=====  Processor composition  =====
Processor name    : 13th Gen Intel(R) Core(TM) i9-13900K  
Packages(sockets) : 1
Cores             : 24
Processors(CPUs)  : 32
Cores per package : 24
Threads per core  : 1

=====  Processor identification  =====
Processor	Thread Id.	Core Id.	Package Id.
0       	0   		0   		0   
1       	1   		0   		0   
2       	0   		4   		0   
3       	1   		4   		0   
4       	0   		8   		0   
5       	1   		8   		0   
6       	0   		12  		0   
7       	1   		12  		0   
8       	0   		16  		0   
9       	1   		16  		0   
10      	0   		20  		0   
11      	1   		20  		0   
12      	0   		24  		0   
13      	1   		24  		0   
14      	0   		28  		0   
15      	1   		28  		0   
16      	0   		32  		0   
17      	0   		33  		0   
18      	0   		34  		0   
19      	0   		35  		0   
20      	0   		36  		0   
21      	0   		37  		0   
22      	0   		38  		0   
23      	0   		39  		0   
24      	0   		40  		0   
25      	0   		41  		0   
26      	0   		42  		0   
27      	0   		43  		0   
28      	0   		44  		0   
29      	0   		45  		0   
30      	0   		46  		0   
31      	0   		47  		0   
=====  Placement on packages  =====
Package Id.	Core Id.	Processors
0   		0,4,8,12,16,20,24,28,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47		(0,1)(2,3)(4,5)(6,7)(8,9)(10,11)(12,13)(14,15)16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31

=====  Cache sharing  =====
Cache	Size		Processors
L1	48  KB		(0,1)(2,3)(4,5)(6,7)(8,9)(10,11)(12,13)(14,15)
L2	2   MB		(0,1)(2,3)(4,5)(6,7)(8,9)(10,11)(12,13)(14,15)(16,17,18,19)(20,21,22,23)(24,25,26,27)(28,29,30,31)
L3	36  MB		(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31)

 

In response to TobiasK
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Rafael_L_Intel
Employee
‎01-22-2024 05:12 AM
1,769 Views
In response to hakostra1

Hello hakostra1,

 

I could reproduce the behaviour in one of our machines. I'll let you know once I have a position from our engineers.

 

Cheers,

Rafael

In response to hakostra1
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hakostra1
New Contributor II
‎01-22-2024 05:15 AM
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That's good to hear, reproducing these issues are often difficult. Pinning is a key feature in any MPI implementation and I hope that you figure out what's going on here. Thanks for the feedback so far!

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Rafael_L_Intel
Employee
‎01-24-2024 07:46 AM
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Hi haokstra1,

 

We disabled the pinning of MPI ranks for the scenario with mixed P- and E-cores in IMPI-2021.11. We recommend to revert to 2021.9 for the time being. We are discussing how to properly address the issue in future releases of Intel MPI. 

 

Cheers,

Rafael

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