<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="">Hello,<div class="">I’m struggling to understand the following weirdness with PCASM with exact subdomain solvers.</div><div class="">I’m dealing with a very simple Poisson problem with Dirichlet + Neumann BCs.</div><div class="">If I use PCBJACOBI + KSPPREONLY or 1 iteration of GMRES either preconditioned on the right or on the left, I get the expected result, cf. attached screenshot.</div><div class="">If I use PCASM + KSPPREONLY or 1 iteration of GMRES preconditioned on the left, I get the expected result as well.</div><div class="">However, with PCASM + 1 iteration of GMRES preconditioned on the right, I don’t get what I should (I believe).</div><div class="">Furthermore, this problem is specific to -pc_asm_type restrict,none (I get the expected result with basic,interpolate).</div><div class=""><br class=""></div><div class="">Any hint?</div><div class=""><br class=""></div><div class="">Thanks,</div><div class="">Pierre</div><div class=""><br class=""></div><div class="">$ -sub_pc_type lu -ksp_max_it 1 -ksp_type gmres -pc_type bjacobi -ksp_pc_side right -> bjacobi_OK</div><div class="">$ -sub_pc_type lu -ksp_max_it 1 -ksp_type gmres -pc_type asm -ksp_pc_side left -> asm_OK</div><div class="">$ -sub_pc_type lu -ksp_max_it 1 -ksp_type gmres -pc_type asm -ksp_pc_side right -> asm_KO</div><div class=""><br class=""></div><div class=""><img apple-inline="yes" id="DE95ED6C-EF37-4B97-922A-62341017FD5C" src="cid:8A870AF3-9D41-482C-9940-CAA8A9190C69@numericable.fr" class=""><img apple-inline="yes" id="07C1457B-CE35-4312-B58C-7416EA187E14" src="cid:3E36D6AE-AABE-4E48-B787-8259DE6B7D7D@numericable.fr" class=""><img apple-inline="yes" id="035EB555-579F-48E6-98DC-ABAFBF26821F" src="cid:1131BD6B-90F8-4AF6-A40F-F2445B325EC1@numericable.fr" class=""></div></body></html>