Yes, I would have expected this to work. Could you send the output from -ksp_view in this case?
> On Jan 13, 2017, at 3:46 AM, Klaij, Christiaan <c.kl...@marin.nl> wrote: > > Barry, > > It's been a while but I'm finally using this function in > 3.7.4. Is it supposed to work with fieldsplit? Here's why. > > I'm solving a Navier-Stokes system with fieldsplit (pc has one > velocity solve and one pressure solve) and trying to retrieve the > totals like this: > > CALL KSPSolve(ksp_system,rr_system,xx_system,ierr); CHKERRQ(ierr) > CALL PCFieldSplitGetSubKSP(pc_system,numsplit,subksp,ierr); CHKERRQ(ierr) > CALL KSPGetTotalIterations(subksp(1),nusediter_vv,ierr); CHKERRQ(ierr) > CALL KSPGetTotalIterations(subksp(2),nusediter_pp,ierr); CHKERRQ(ierr) > print *, 'nusediter_vv', nusediter_vv > print *, 'nusediter_pp', nusediter_pp > > Running the code shows this surprise: > > Linear sys_fieldsplit_0_ solve converged due to CONVERGED_RTOL iterations 1 > Linear sys_fieldsplit_0_ solve converged due to CONVERGED_RTOL iterations 1 > Linear sys_fieldsplit_0_ solve converged due to CONVERGED_RTOL iterations 2 > Linear sys_fieldsplit_0_ solve converged due to CONVERGED_RTOL iterations 2 > Linear sys_fieldsplit_0_ solve converged due to CONVERGED_RTOL iterations 7 > Linear sys_fieldsplit_0_ solve converged due to CONVERGED_RTOL iterations 7 > Linear sys_fieldsplit_0_ solve converged due to CONVERGED_RTOL iterations 7 > Linear sys_fieldsplit_0_ solve converged due to CONVERGED_RTOL iterations 7 > Linear sys_fieldsplit_0_ solve converged due to CONVERGED_RTOL iterations 8 > Linear sys_fieldsplit_0_ solve converged due to CONVERGED_RTOL iterations 8 > Linear sys_fieldsplit_0_ solve converged due to CONVERGED_RTOL iterations 8 > Linear sys_fieldsplit_0_ solve converged due to CONVERGED_RTOL iterations 8 > > Linear sys_fieldsplit_1_ solve converged due to CONVERGED_RTOL iterations 22 > Linear sys_fieldsplit_1_ solve converged due to CONVERGED_RTOL iterations 6 > Linear sys_fieldsplit_1_ solve converged due to CONVERGED_RTOL iterations 3 > Linear sys_fieldsplit_1_ solve converged due to CONVERGED_RTOL iterations 2 > Linear sys_fieldsplit_1_ solve converged due to CONVERGED_RTOL iterations 2 > Linear sys_fieldsplit_1_ solve converged due to CONVERGED_RTOL iterations 2 > > nusediter_vv 37 > nusediter_pp 37 > > So the value of nusediter_pp is indeed 37, but for nusediter_vv > it should be 66. Any idea what went wrong? > > Chris > > > > dr. ir. Christiaan Klaij | CFD Researcher | Research & Development > MARIN | T +31 317 49 33 44 | mailto:c.kl...@marin.nl | http://www.marin.nl > > MARIN news: > http://www.marin.nl/web/News/News-items/MARIN-wishes-you-a-challenging-inspiring-2017.htm > > ________________________________________ > From: Barry Smith <bsm...@mcs.anl.gov> > Sent: Saturday, April 11, 2015 12:27 AM > To: Klaij, Christiaan > Cc: petsc-users@mcs.anl.gov > Subject: Re: [petsc-users] monitoring the convergence of fieldsplit 0 and 1 > > Chris, > > I have added KSPGetTotalIterations() to the branch > barry/add-ksp-total-iterations/master and next. After tests it will go into > master > > Barry > >> On Apr 10, 2015, at 8:07 AM, Klaij, Christiaan <c.kl...@marin.nl> wrote: >> >> Barry, >> >> Sure, I can call PCFieldSplitGetSubKSP() to get the fieldsplit_0 >> ksp and then KSPGetIterationNumber, but what does this number >> mean? >> >> It appears to be the number of iterations of the last time that >> the subsystem was solved, right? If so, this corresponds to the >> last iteration of the coupled system, how about all the previous >> iterations? >> >> Chris >> ________________________________________ >> From: Barry Smith <bsm...@mcs.anl.gov> >> Sent: Friday, April 10, 2015 2:48 PM >> To: Klaij, Christiaan >> Cc: petsc-users@mcs.anl.gov >> Subject: Re: [petsc-users] monitoring the convergence of fieldsplit 0 and 1 >> >> Chris, >> >> It appears you should call PCFieldSplitGetSubKSP() and then get the >> information you want out of the individual KSPs. If this doesn't work please >> let us know. >> >> Barry >> >>> On Apr 10, 2015, at 6:48 AM, Klaij, Christiaan <c.kl...@marin.nl> wrote: >>> >>> A question when using PCFieldSplit: for each linear iteration of >>> the system, how many iterations for fielsplit 0 and 1? >>> >>> One way to find out is to run with -ksp_monitor, >>> -fieldsplit_0_ksp_monitor and -fieldsplit_0_ksp_monitor. This >>> gives the complete convergence history. >>> >>> Another way, suggested by Matt, is to use -ksp_monitor, >>> -fieldsplit_0_ksp_converged_reason and >>> -fieldsplit_1_ksp_converged_reason. This gives only the totals >>> for fieldsplit 0 and 1 (but without saying for which one). >>> >>> Both ways require to somehow process the output, which is a bit >>> inconvenient. Could KSPGetResidualHistory perhaps return (some) >>> information on the subsystems' convergence for processing inside >>> the code? >>> >>> Chris >>> >>> >>> dr. ir. Christiaan Klaij >>> CFD Researcher >>> Research & Development >>> E mailto:c.kl...@marin.nl >>> T +31 317 49 33 44 >>> >>> >>> MARIN >>> 2, Haagsteeg, P.O. Box 28, 6700 AA Wageningen, The Netherlands >>> T +31 317 49 39 11, F +31 317 49 32 45, I www.marin.nl >>> >> >