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,
put type='hidden' name='id' value='03592a6f882f5b4309f77c3dc3e65559d7b7cb75'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=03592a6f882f5b4309f77c3dc3e65559d7b7cb75'>root</a>/<a href='/guix/log/gnu?id=03592a6f882f5b4309f77c3dc3e65559d7b7cb75'>gnu</a>/<a href='/guix/log/gnu/packages?id=03592a6f882f5b4309f77c3dc3e65559d7b7cb75'>packages</a>/<a href='/guix/log/gnu/packages/calendar.scm?id=03592a6f882f5b4309f77c3dc3e65559d7b7cb75'>calendar.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/gnu/packages/calendar.scm?id=03592a6f882f5b4309f77c3dc3e65559d7b7cb75&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2018-10-12 23:42:43 -0400'>2018-10-12</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=f1be3735db479157f3c83922a4e60608ebd7165a'>gnu: khal: Update to 0.9.10.</a><span class='msg-avail'>...</span></td><td>Leo Famulari</td></tr>
<tr><td><span title='2018-05-31 04:54:56 +0200'>2018-05-31</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=6c738fe9e7e6a95ce910f5a22e6f2c869075ec2d'>gnu: khal: Use INVOKE.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2018-05-29 00:41:32 -0400'>2018-05-29</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=2a49aee4d120cd3a8bfd855578f0b8832db88227'>gnu: khal: Update to 0.9.9.</a><span class='msg-avail'>...</span></td><td>Leo Famulari</td></tr>
<tr><td><span title='2018-03-12 17:28:14 +0100'>2018-03-12</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=fe2520c389d7c8dced432e9687d51f19fba817d6'>gnu: libical: Update to 3.0.3.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2018-02-20 17:58:11 +0100'>2018-02-20</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=09183df2093614c624ac59563c7c159d82db7792'>gnu: libical: Update to 3.0.2.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2018-02-20 14:58:52 +0100'>2018-02-20</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=1eaba63f7360b4339e041fc17d4487d692be5427'>gnu: calendar.scm: Use license: prefix.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2017-12-19 19:52:01 +0200'>2017-12-19</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=677bc34d5b75d4c9a8020f9d0f917c3ca2fb3dc6'>gnu: Remove redundant cmake libdir configure flags.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2017-11-19 15:01:00 +0100'>2017-11-19</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=2dd12924cf4a30a96262b6d392fcde58c9f10d4b'>Merge branch 'master' into core-updates</a></td><td>Marius Bakke</td></tr>
<tr><td><span title='2017-11-18 12:45:19 +0100'>2017-11-18</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=33dc54b08c5b56fbe87229fe05f5c7de8c6f1179'>gnu: Move date/time packages from python.scm to time.scm.</a><span class='msg-avail'>...</span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2017-11-17 22:36:26 +0100'>2017-11-17</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=ac257f127ac5e1fd4758d3a05e4a19fde3af4e01'>gnu: Move testing packages from python.scm to check.scm.</a><span class='msg-avail'>...</span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2017-10-19 00:16:49 +0200'>2017-10-19</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=928da609b53e0fc177d9dc99d69b0cb884d021a3'>gnu: Remove python-pytest@2.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2017-10-07 13:14:50 -0400'>2017-10-07</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=3202d601a82022c5e9563b60db5b9a6458593ac8'>gnu: khal: Update to 0.9.8.</a><span class='msg-avail'>...</span></td><td>Leo Famulari</td></tr>
<tr><td><span title='2017-09-28 12:26:50 +0300'>2017-09-28</span></td><td><a href='/guix/commit/gnu/packages/calendar.scm?id=523ecbbbedfed6bd902309286e00a6f04b1ff195'>gnu: libical: Fix libdir install path.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>