<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">OK, thanks to the both of you.<div class="">It now makes more sense to me why you do all these copying around in PCTELESCOPE, e.g., <a href="http://www.mcs.anl.gov/petsc/petsc-current/src/ksp/pc/impls/telescope/telescope.c.html#line469" class="">http://www.mcs.anl.gov/petsc/petsc-current/src/ksp/pc/impls/telescope/telescope.c.html#line469</a>.</div><div class=""><br class=""></div><div class="">Pierre</div><div class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 10 Sep 2018, at 5:14 AM, Jed Brown <<a href="mailto:jed@jedbrown.org" class="">jed@jedbrown.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">"Smith, Barry F." <<a href="mailto:bsmith@mcs.anl.gov" class="">bsmith@mcs.anl.gov</a>> writes:<br class=""><br class=""><blockquote type="cite" class=""> It is not possible to do this. When communicating parallel to parallel the communicator for both vectors must be the same communicator. <br class=""></blockquote><br class="">Note that one can use VecPlaceArray as part of the communication so you<br class="">don't need a copy to get it on a different subcommunicator. Perhaps<br class="">that could be made automatic at a future date, after the ongoing<br class="">VecScatter refactoring has completed.<br class=""></div></div></blockquote></div><br class=""></div></body></html>