PSM2 is the only valid implementation for OmniPath (OPA).  UCX also
supports OmniPath, but it does so via Verbs, thus getting much lower
performance (typically 3 GiB/s instead of 10 GiB/s).

To work around that, give the mtl_psm2 component a higher priority
than the pml_ucx component.

See <https://www.mail-archive.com/users@lists.open-mpi.org/msg33581.html>.

--- openmpi-4.0.2/ompi/mca/mtl/psm2/mtl_psm2_component.c	2019-11-15 17:06:15.142076840 +0100
+++ openmpi-4.0.2/ompi/mca/mtl/psm2/mtl_psm2_component.c	2019-11-15 17:06:22.242009379 +0100
@@ -126,7 +126,7 @@ ompi_mtl_psm2_component_register(void)
         setenv("PSM2_DEVICES", "self,shm", 0);
     }
 
-    param_priority = 40;
+    param_priority = 55;
     (void) mca_base_component_var_register (&mca_mtl_psm2_component.super.mtl_version,
                                             "priority", "Priority of the PSM2 MTL component",
                                             MCA_BASE_VAR_TYPE_INT, NULL, 0, 0,

Likewise for PSM: we want InfiniPath to be taken care of by PSM, not by UCX,
since UCX achieves worse performance.

--- openmpi-4.0.2/ompi/mca/mtl/psm/mtl_psm_component.c
+++ openmpi-4.0.2/ompi/mca/mtl/psm/mtl_psm_component.c
@@ -92,7 +92,7 @@ ompi_mtl_psm_component_register(void)
 
 
     /* set priority high enough to beat ob1's default */
-    param_priority = 30;
+    param_priority = 54;
     (void) mca_base_component_var_register (&mca_mtl_psm_component.super.mtl_version,
                                             "priority", "Priority of the PSM MTL component",
                                             MCA_BASE_VAR_TYPE_INT, NULL, 0, 0,
'/guix/log/build-aux/check-channel-news.scm'>
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<div class='path'>path: <a href='/guix/log/?id=c91514edd18c2b552d21a3895fd19411155403cc'>root</a>/<a href='/guix/log/build-aux?id=c91514edd18c2b552d21a3895fd19411155403cc'>build-aux</a>/<a href='/guix/log/build-aux/check-channel-news.scm?id=c91514edd18c2b552d21a3895fd19411155403cc'>check-channel-news.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/build-aux/check-channel-news.scm?id=c91514edd18c2b552d21a3895fd19411155403cc&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-05-22 00:35:23 +0200'>2020-05-22</span></td><td><a href='/guix/commit/build-aux/check-channel-news.scm?id=1ad5209d904d471ded6cf53b4e29b64e963dea3f'>maint: Add "make check-channel-news".</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
UTHORS?id=1d642af9872949633b1084f53352f3c851f41810'>Add Claes Wallin to 'AUTHORS'.</a></td><td>Alex Kost</td></tr>
<tr><td><span title='2015-04-26 21:38:37 -0400'>2015-04-26</span></td><td><a href='/guix/commit/AUTHORS?id=6bc24063155d897c6c80a192e48bd9f61cb9014e'>gnu: Add guile-minikanren.</a><span class='msg-avail'>...</span></td><td>Christopher Allan Webber</td></tr>
<tr><td><span title='2015-04-05 23:15:20 +0200'>2015-04-05</span></td><td><a href='/guix/commit/AUTHORS?id=bc45ceb5ffb445ca26a6cd5ac34f39d0dedd8504'>Add Andy to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2015-03-09 20:26:44 -0400'>2015-03-09</span></td><td><a href='/guix/commit/AUTHORS?id=1cf0814d4d89737d7a61bc64650ea5ac58fff7cb'>Add Paul to 'AUTHORS'.</a></td><td>Mark H Weaver</td></tr>
<tr><td><span title='2015-03-09 23:51:43 +0100'>2015-03-09</span></td><td><a href='/guix/commit/AUTHORS?id=e92da92d63d0b50d462fc3608b19d18ac239d87b'>Add Alexander to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2015-02-20 10:14:23 +0100'>2015-02-20</span></td><td><a href='/guix/commit/AUTHORS?id=76aae0f96f3aed10e842b1726ffc19848600c04d'>Add David Hashe to 'AUTHORS'.</a></td><td>Andreas Enge</td></tr>
<tr><td><span title='2015-02-02 12:46:35 +0100'>2015-02-02</span></td><td><a href='/guix/commit/AUTHORS?id=1af50c224d7d8febad0cf34b67d0ffd6c2dff638'>Add Deck to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2015-01-24 22:57:49 +0100'>2015-01-24</span></td><td><a href='/guix/commit/AUTHORS?id=da74bc7886cba77192260d84b2dd57466e4b5354'>Add Ricardo to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2014-12-09 13:19:47 +0100'>2014-12-09</span></td><td><a href='/guix/commit/AUTHORS?id=03356e977567b76e981c04af20302018f9f02fac'>Add Tomáš to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2014-11-18 22:03:03 +0100'>2014-11-18</span></td><td><a href='/guix/commit/AUTHORS?id=418367f7f0d209b6a1251ab8e33c5233dd099a26'>Add Julien to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2014-11-14 22:58:18 +0100'>2014-11-14</span></td><td><a href='/guix/commit/AUTHORS?id=f21ca31d15a7a9bd8aaf221c0a2c97b2d08980e9'>Add the name of Sou Bunnbu in its original script to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2014-11-12 14:39:30 +0100'>2014-11-12</span></td><td><a href='/guix/commit/AUTHORS?id=dc05f01cba88bc768a0b12ecfb3760073ff0bc47'>Add Sun Bunnbu to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2014-10-26 14:48:57 +0100'>2014-10-26</span></td><td><a href='/guix/commit/AUTHORS?id=822efdff8a52ba50a84a6f138e22468dc824174b'>Update name and email address for Joshua Grant.</a></td><td>Joshua Grant</td></tr>
<tr><td><span title='2014-10-08 22:12:06 +0200'>2014-10-08</span></td><td><a href='/guix/commit/AUTHORS?id=9c814b828ae07899594ad9cd83d2e77e4cc528cc'>Add Federico to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2014-09-10 15:44:51 +0200'>2014-09-10</span></td><td><a href='/guix/commit/AUTHORS?id=6e4532e8fec5b31fad38be82ada46b5a70952b91'>Add Marek to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2014-08-15 16:26:28 +0200'>2014-08-15</span></td><td><a href='/guix/commit/AUTHORS?id=25290d2766d4bc5c2edd1cddd053de74a93cc4e3'>Update AUTHORS and THANKS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2014-07-18 06:45:33 +0200'>2014-07-18</span></td><td><a href='/guix/commit/AUTHORS?id=cdd754e8b64cbce7242f3461319679ae9748511d'>Update 'AUTHORS'.</a><span class='msg-avail'>...</span></td><td>John Darrington</td></tr>
<tr><td><span title='2014-07-15 22:48:48 +0200'>2014-07-15</span></td><td><a href='/guix/commit/AUTHORS?id=31469764960fbc81c7875a6dd7770300db5ccf05'>Add Jason to 'AUTHORS'.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2014-06-29 22:38:38 +0200'>2014-06-29</span></td><td><a href='/guix/commit/AUTHORS?id=1abb614051c9b4299279c21e541bc1a7d2e99155'>Add Cyrill to AUTHORS.</a></td><td>Ludovic Courtès</td></tr>