PERF-2 P0-b: CG iterations per Poisson solve in the profile (ms per V-cycle) and sub-timers inside the patch regeneration (outline, hull + offset, ring projection, Winslow sweeps, respace, warm bookkeeping, mesh finalisation)

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

@@ -168,9 +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)>,
+    /// PERF-2 P0: Poisson `(setup ns, iterate ns, calls, CG iterations)`
+    /// summed over every multigrid-PCG solve (`docs/perf2_campaign.md`).
+    poisson_profile: std::cell::Cell<(u64, u64, u64, u64)>,
     moving: bool,
     /// Mask hysteresis band in multiples of the min cell size (0 = off).
     mask_hysteresis: f64,
@@ -197,7 +197,7 @@ impl EmbeddedPisoSolver {
             fringe: None,
             fringe_correction: Vec::new(),
             inner_stop_factor: 1e-2,
-            poisson_profile: std::cell::Cell::new((0, 0, 0)),
+            poisson_profile: std::cell::Cell::new((0, 0, 0, 0)),
             moving: false,
             mask_hysteresis: 0.0,
             time: 0.0,
@@ -294,8 +294,8 @@ 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) {
+    /// The Poisson solves' `(setup ns, iterate ns, calls, CG iterations)` so far.
+    pub fn poisson_profile(&self) -> (u64, u64, u64, u64) {
         self.poisson_profile.get()
     }
 

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

@@ -304,9 +304,13 @@ 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));
+            let (s0, i0, c0, k0) = self.poisson_profile.get();
+            self.poisson_profile.set((
+                s0 + solution.setup_ns,
+                i0 + solution.iterate_ns,
+                c0 + 1,
+                k0 + solution.iterations as u64,
+            ));
             // 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;