<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=""><div class=""><div>You should swap fieldsplit and ASM</div><div><br class=""></div><div>-pc_type fieldsplit</div><div>-fieldsplit_0_pc_type asm</div><div>….</div><div><br class=""></div><div><br class=""><blockquote type="cite" class=""><div class="">On Dec 31, 2020, at 10:19 PM, Mark Adams <<a href="mailto:mfadams@lbl.gov" class="">mfadams@lbl.gov</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><span style="color:rgb(80,0,80)" class="">PCFieldSplitSetDefaults is called from </span>PCSetUpOnBlocks and there is only one block. So it is called from a subpc, which does not have a DM and it's too late anyway.<div class=""><div class=""><br class=""></div><div class="">#14 main (argc=<optimized out>, argv=<optimized out>) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ts/utils/dmplexlandau/tutorials/ex2.c:774 (at 0x0000000010002a28)<br class="">#13 TSSolve (ts=0x83638480, u=0x8338de50) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ts/interface/ts.c:4168 (at 0x00002000015e60e4)<br class="">#12 TSStep (ts=0x83638480) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ts/interface/ts.c:3771 (at 0x00002000015e416c)<br class="">#11 TSStep_ARKIMEX (ts=0x83638480) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ts/impls/arkimex/arkimex.c:845 (at 0x000020000165e97c)<br class="">#10 SNESSolve (snes=0x83639d20, b=0x0, x=0x8338f320) at /gpfs/alpine/csc314/scratch/adams/petsc/src/snes/interface/snes.c:4563 (at 0x00002000014f2b98)<br class="">#9 SNESSolve_NEWTONLS (snes=0x83639d20) at /gpfs/alpine/csc314/scratch/adams/petsc/src/snes/impls/ls/ls.c:225 (at 0x0000200001553d34)<br class="">#8 KSPSolve (ksp=0x8363a610, b=0x8363db00, x=0x83642350) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ksp/ksp/interface/itfunc.c:963 (at 0x000020000138987c)<br class="">#7 KSPSolve_Private (ksp=0x8363a610, b=0x8363db00, x=0x83642350) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ksp/ksp/interface/itfunc.c:727 (at 0x0000200001386d70)<br class="">#6 KSPSetUpOnBlocks (ksp=0x8363a610) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ksp/ksp/interface/itfunc.c:214 (at 0x0000200001381a6c)<br class="">#5 PCSetUpOnBlocks (pc=0x8338afe0) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ksp/pc/interface/precon.c:1046 (at 0x0000200001333aa0)<br class="">#4 PCSetUpOnBlocks_ASM (pc=0x8338afe0) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ksp/pc/impls/asm/asm.c:437 (at 0x00002000012cb87c)<br class="">#3 KSPSetUp (ksp=0x836486c0) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ksp/ksp/interface/itfunc.c:406 (at 0x0000200001383258)<br class="">#2 PCSetUp (pc=0x83645200) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ksp/pc/interface/precon.c:1015 (at 0x00002000013335f0)<br class="">#1 PCSetUp_FieldSplit (pc=0x83645200) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ksp/pc/impls/fieldsplit/fieldsplit.c:614 (at 0x00002000012a27f4)<br class="">#0 PCFieldSplitSetDefaults (pc=0x83645200) at /gpfs/alpine/csc314/scratch/adams/petsc/src/ksp/pc/impls/fieldsplit/fieldsplit.c:398 (at 0x000020000129f854)<br class=""></div></div></div><br class=""><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Dec 31, 2020 at 1:56 PM Matthew Knepley <<a href="mailto:knepley@gmail.com" class="">knepley@gmail.com</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr" class=""><div dir="ltr" class="">On Thu, Dec 31, 2020 at 1:50 PM Mark Adams <<a href="mailto:mfadams@lbl.gov" target="_blank" class="">mfadams@lbl.gov</a>> wrote:<br class=""></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr" class=""><div dir="ltr" class="">On Thu, Dec 31, 2020 at 1:12 PM Matthew Knepley <<a href="mailto:knepley@gmail.com" target="_blank" class="">knepley@gmail.com</a>> wrote:<br class=""></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr" class=""><div dir="ltr" class="">On Thu, Dec 31, 2020 at 12:46 PM Mark Adams <<a href="mailto:mfadams@lbl.gov" target="_blank" class="">mfadams@lbl.gov</a>> wrote:<br class=""></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr" class=""><div dir="ltr" class="">Still missing something:</div></div></blockquote><div class=""><br class=""></div><div class="">You can get in the debugger in PCFieldSplitSetDefaults(), but the most likely thing is that pc->dm == NULL here, </div></div></div></blockquote><div class=""><br class=""></div><div class="">the setuponblocks PC does have a DM and it is a cusparse mattype.</div></div></div></blockquote><div class=""><br class=""></div><div class="">Then go in the debugger and see why that option is not being used.</div><div class=""><br class=""></div><div class=""> Matt</div><div class=""> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr" class=""><div class="gmail_quote"><div class=""> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr" class=""><div class="gmail_quote"><div class="">so the PC is not getting the DM.</div><div class="">This does make some sense as you are doing ASM, which is ripping up the domain, so you might not want the same DM on the subproblem. I</div><div class="">am not sure what should be done here.</div><div class=""><br class=""></div></div></div>
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</blockquote></div><br clear="all" class=""><div class=""><br class=""></div>-- <br class=""><div dir="ltr" class=""><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class="">What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br class="">-- Norbert Wiener</div><div class=""><br class=""></div><div class=""><a href="http://www.cse.buffalo.edu/~knepley/" target="_blank" class="">https://www.cse.buffalo.edu/~knepley/</a><br class=""></div></div></div></div></div></div></div></div>
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