PERF-2 P0: intra-step profiler — StepTimers on the overset solver (RTX_PROFILE; overlap build / predictors / patch BiCGSTAB / background Poisson with its setup-vs-iterate split / round exchange / apply / end exchange), PoissonSolution carries setup_ns and iterate_ns, the harness times advance / restore / snapshot / load sampling / force / FEA predictor and prints the wall split of the coupled phase; no clock is read when profiling is off; the reclassified/step progress denominator fixed (was ×4)

Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01YJPeT6WA2e7YvAnS875AHL

crates/specialized/rtx-cfd/src/solvers/incompressible/embedded/mod.rs

@@ -41,7 +41,7 @@ mod projection;
 use super::ale::{AleBoundaries, SideBoundary};
 use super::embedded_body::{EmbeddedBody, EmbeddedMask, FaceKind};
 use super::poisson::{
-    solve_multigrid_pcg, MgPrecision, MultigridParameters, PoissonProblem, PoissonSolverKind,
+    MgPrecision, MultigridParameters, PoissonProblem, PoissonSolverKind, solve_multigrid_pcg,
 };
 use super::simple::ConvectionScheme;
 use super::{FlowField, SolverResult};
@@ -168,6 +168,9 @@ pub struct EmbeddedPisoSolver {
     /// (measured: at 1e-2 the first corrector's rounds never settled below
     /// a 1e-3 relative change — 20/20 rounds every step).
     inner_stop_factor: f64,
+    /// PERF-2 P0: Poisson `(setup ns, iterate ns, calls)` summed over
+    /// every multigrid-PCG solve (`docs/perf2_campaign.md`).
+    poisson_profile: std::cell::Cell<(u64, u64, u64)>,
     moving: bool,
     /// Mask hysteresis band in multiples of the min cell size (0 = off).
     mask_hysteresis: f64,
@@ -194,6 +197,7 @@ impl EmbeddedPisoSolver {
             fringe: None,
             fringe_correction: Vec::new(),
             inner_stop_factor: 1e-2,
+            poisson_profile: std::cell::Cell::new((0, 0, 0)),
             moving: false,
             mask_hysteresis: 0.0,
             time: 0.0,
@@ -290,6 +294,11 @@ impl EmbeddedPisoSolver {
     }
 
     /// Relative part of the pressure solve's inner stop (see the field).
+    /// The Poisson solves' `(setup ns, iterate ns, calls)` so far.
+    pub fn poisson_profile(&self) -> (u64, u64, u64) {
+        self.poisson_profile.get()
+    }
+
     pub fn set_inner_stop_factor(&mut self, factor: f64) {
         self.inner_stop_factor = factor;
     }

crates/specialized/rtx-cfd/src/solvers/incompressible/embedded/projection.rs

@@ -4,12 +4,12 @@
 //! meshes before applying the correction once.
 
 use super::EmbeddedPisoSolver;
+use crate::CfdResult;
 use crate::solvers::incompressible::ale::SideBoundary;
 use crate::solvers::incompressible::poisson::{
-    solve_multigrid_pcg, MultigridParameters, PoissonProblem, PoissonSolverKind,
+    MultigridParameters, PoissonProblem, PoissonSolverKind, solve_multigrid_pcg,
 };
 use crate::solvers::incompressible::{EmbeddedMask, FlowField};
-use crate::CfdResult;
 
 impl EmbeddedPisoSolver {
     /// The pressure-correction system of one projection as a
@@ -304,6 +304,9 @@ impl EmbeddedPisoSolver {
                 inner_stop,
                 anchor_cell,
             );
+            let (s0, i0, c0) = self.poisson_profile.get();
+            self.poisson_profile
+                .set((s0 + solution.setup_ns, i0 + solution.iterate_ns, c0 + 1));
             // Unconverged: fall back to the SOR sweeps for this projection
             // rather than apply a correction that did not reach the stop.
             multigrid_converged = solution.converged;
@@ -337,44 +340,28 @@ impl EmbeddedPisoSolver {
                         // prescribed: a domain side with velocity data, or a
                         // non-fluid interior face.
                         let ae = if i + 1 == nx {
-                            if b.right == outlet {
-                                ae_outlet
-                            } else {
-                                0.0
-                            }
+                            if b.right == outlet { ae_outlet } else { 0.0 }
                         } else if self.u_is_fluid(j, i + 1) {
                             ae_interior
                         } else {
                             0.0
                         };
                         let aw = if i == 0 {
-                            if b.left == outlet {
-                                ae_outlet
-                            } else {
-                                0.0
-                            }
+                            if b.left == outlet { ae_outlet } else { 0.0 }
                         } else if self.u_is_fluid(j, i) {
                             ae_interior
                         } else {
                             0.0
                         };
                         let an = if j + 1 == ny {
-                            if b.top == outlet {
-                                an_outlet
-                            } else {
-                                0.0
-                            }
+                            if b.top == outlet { an_outlet } else { 0.0 }
                         } else if self.v_is_fluid(j + 1, i) {
                             an_interior
                         } else {
                             0.0
                         };
                         let as_ = if j == 0 {
-                            if b.bottom == outlet {
-                                an_outlet
-                            } else {
-                                0.0
-                            }
+                            if b.bottom == outlet { an_outlet } else { 0.0 }
                         } else if self.v_is_fluid(j, i) {
                             an_interior
                         } else {