Can you please run the same thing without the KSPGuess option(s) for a baseline comparison?
Thanks Barry > On Jun 13, 2024, at 1:27 PM, Yongzhong Li <yongzhong...@mail.utoronto.ca> > wrote: > > This Message Is From an External Sender > This message came from outside your organization. > Hi Matt, > > I have rerun the program with the keys you provided. The system output when > performing ksp solve and the final petsc log output were stored in a .txt > file attached for your reference. > > Thanks! > Yongzhong > > From: Matthew Knepley <knep...@gmail.com <mailto:knep...@gmail.com>> > Date: Wednesday, June 12, 2024 at 6:46 PM > To: Yongzhong Li <yongzhong...@mail.utoronto.ca > <mailto:yongzhong...@mail.utoronto.ca>> > Cc: petsc-users@mcs.anl.gov <mailto:petsc-users@mcs.anl.gov> > <petsc-users@mcs.anl.gov <mailto:petsc-users@mcs.anl.gov>>, > petsc-ma...@mcs.anl.gov <mailto:petsc-ma...@mcs.anl.gov> > <petsc-ma...@mcs.anl.gov <mailto:petsc-ma...@mcs.anl.gov>>, Piero Triverio > <piero.trive...@utoronto.ca <mailto:piero.trive...@utoronto.ca>> > Subject: Re: [petsc-maint] Assistance Needed with PETSc KSPSolve Performance > Issue > > 你通常不会收到来自 knep...@gmail.com <mailto:knep...@gmail.com> 的电子邮件。了解这一点为什么很重要 > <https://urldefense.us/v3/__https://aka.ms/LearnAboutSenderIdentification__;!!G_uCfscf7eWS!djGfJnEhNJROfsMsBJy5u_KoRKbug55xZ64oHKUFnH2cWku_Th1hwt4TDdoMd8pWYVDzJeqJslMNZwpO3y0Et94d31qk-oCEwo4$> > > On Wed, Jun 12, 2024 at 6:36 PM Yongzhong Li <yongzhong...@mail.utoronto.ca > <mailto:yongzhong...@mail.utoronto.ca>> wrote: > Dear PETSc’s developers, I hope this email finds you well. I am currently > working on a project using PETSc and have encountered a performance issue > with the KSPSolve function. Specifically, I have noticed that the time taken > by KSPSolve is > ZjQcmQRYFpfptBannerStart > This Message Is From an External Sender > This message came from outside your organization. > > ZjQcmQRYFpfptBannerEnd > Dear PETSc’s developers, > I hope this email finds you well. > I am currently working on a project using PETSc and have encountered a > performance issue with the KSPSolve function. Specifically, I have noticed > that the time taken by KSPSolve is almost two times greater than the CPU time > for matrix-vector product multiplied by the number of iteration steps. I use > C++ chrono to record CPU time. > For context, I am using a shell system matrix A. Despite my efforts to > parallelize the matrix-vector product (Ax), the overall solve time remains > higher than the matrix vector product per iteration indicates when multiple > threads were used. Here are a few details of my setup: > Matrix Type: Shell system matrix > Preconditioner: Shell PC > Parallel Environment: Using Intel MKL as PETSc’s BLAS/LAPACK library, > multithreading is enabled > I have considered several potential reasons, such as preconditioner setup, > additional solver operations, and the inherent overhead of using a shell > system matrix. However, since KSPSolve is a high-level API, I have been > unable to pinpoint the exact cause of the increased solve time. > Have you observed the same issue? Could you please provide some experience on > how to diagnose and address this performance discrepancy? Any insights or > recommendations you could offer would be greatly appreciated. > > For any performance question like this, we need to see the output of your > code run with > > -ksp_view -ksp_monitor_true_residual -ksp_converged_reason -log_view > > Thanks, > > Matt > > Thank you for your time and assistance. > Best regards, > Yongzhong > ----------------------------------------------------------- > Yongzhong Li > PhD student | Electromagnetics Group > Department of Electrical & Computer Engineering > University of Toronto > https://urldefense.us/v3/__http://www.modelics.org__;!!G_uCfscf7eWS!fauKPPSN6fIvLxuqYn1CRvpUf5q9zeWauAOP28SBKtXHbucpJwjmXGMcWD21S3qRjSPoyFZTDYG9jPhI5dAE71E$ > > <https://urldefense.us/v3/__http://www.modelics.org__;!!G_uCfscf7eWS!cuLttMJEcegaqu461Bt4QLsO4fASfLM5vjRbtyNhWJQiInbjgNwkGNdkFE1ebSbFjOUatYB0-jd2yQWMWzqkDFFjwMvNl3ZKAr8$> > > > > -- > What most experimenters take for granted before they begin their experiments > is infinitely more interesting than any results to which their experiments > lead. > -- Norbert Wiener > > https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!fauKPPSN6fIvLxuqYn1CRvpUf5q9zeWauAOP28SBKtXHbucpJwjmXGMcWD21S3qRjSPoyFZTDYG9jPhIrXxdS4M$ > > <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!djGfJnEhNJROfsMsBJy5u_KoRKbug55xZ64oHKUFnH2cWku_Th1hwt4TDdoMd8pWYVDzJeqJslMNZwpO3y0Et94d31qkNOuenGA$><ksp_petsc_log.txt>
