<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""></div><div> My guess is it related to the file system, possible caching executables and/or shared libraries. I can't see any thing in PETSc that could possible affect the start up speed based on the last time it was run.</div><div><br class=""></div><div> You can run with -info to see how quickly the output comes when you start the run.</div><div><br class=""></div><div> Barry</div><div><br class=""><blockquote type="cite" class=""><div class="">On Jul 27, 2022, at 7:42 AM, LEDAC Pierre <<a href="mailto:Pierre.LEDAC@cea.fr" class="">Pierre.LEDAC@cea.fr</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta charset="UTF-8" class=""><div id="divtagdefaultwrapper" dir="ltr" style="font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-size: 12pt; font-family: Calibri, Helvetica, sans-serif;" class=""><div style="margin-top: 0px; margin-bottom: 0px;" class="">Hello,</div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class="">Recently migrated from Fedora34 to Fedora36, using PETSc I have some lag during the PetscInitialize, which</div><div style="margin-top: 0px; margin-bottom: 0px;" class="">disappeared if I run again immediately the binary. But after few seconds, the lag happens again (see below).</div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class="">I suspected MPICH 4.0.2 on Fedora36, but a small reproducer indicated the issue is not in MPI_Init but really during PetscInitialize<br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class="">Just annoying during testing, not very important, but did someone already see this ?</div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class="">Thanks,<br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><br class=""></div><p style="margin-top: 0px; margin-bottom: 0px;" class=""></p><div class="">portable: /volatile/ledacp/petsc/src/ksp/ksp/tests (main) > time ./ex39<br class=""><br class=""><span style="color: rgb(255, 0, 0);" class="">real 0m3,593s</span><br class="">user 0m0,872s<br class="">sys 0m0,433s<br class="">portable: /volatile/ledacp/petsc/src/ksp/ksp/tests (main) > time ./ex39<br class=""><br class="">real 0m0,310s<br class="">user 0m0,884s<br class="">sys 0m0,023s<br class=""></div><div class=""><br class=""></div><div class=""># Wait ~20 seconds then again:<br class=""></div><div class=""><br class=""></div><div class="">portable: /volatile/ledacp/petsc/src/ksp/ksp/tests (main) > time ./ex39<br class=""><br class=""><span style="color: rgb(255, 0, 0);" class="">real 0m3,507s</span><br class="">user 0m0,897s<br class="">sys 0m0,025s<br class="">portable: /volatile/ledacp/petsc/src/ksp/ksp/tests (main) > time ./ex39<br class=""><br class="">real 0m0,154s<br class="">user 0m0,725s<br class="">sys 0m0,015s<br class="">portable: /volatile/ledacp/petsc/src/ksp/ksp/tests (main) > time ./ex39<br class=""><br class="">real 0m0,176s<br class="">user 0m0,875s<br class="">sys 0m0,021s<br class=""><br class=""></div><br class=""><p style="margin-top: 0px; margin-bottom: 0px;" class=""></p><div id="Signature" class=""><div style="font-family: Tahoma; font-size: 13px;" class=""><div class="BodyFragment"><font size="2" class=""><span style="font-size: 10pt;" class=""><div class="PlainText">Pierre LEDAC<br class="">Commissariat à l’énergie atomique et aux énergies alternatives<br class="">Centre de SACLAY<br class="">DES/ISAS/DM2S/STMF/LGLS<br class="">Bâtiment 451 – point courrier n°43<br class="">F-91191 Gif-sur-Yvette<br class="">+33 1 69 08 04 03<br class="">+33 6 83 42 05 79</div></span></font></div></div></div></div><span id="cid:107E21E2-E283-47D6-A061-1B1D7EEFF4B0"><petscmachineinfo.h></span></div></blockquote></div><br class=""></body></html>