From 0fbdd743a07c3cd287339fac28cd24f2b98b6435 Mon Sep 17 00:00:00 2001
From: Daniel Han
Date: Fri, 3 Jul 2026 11:10:40 +0000
Subject: [PATCH] Report grad norm from the trainers and chart it instead of
LR; celebrate completion in the run header
---
.../core/training/diffusion_dit_trainer.py | 6 ++-
.../core/training/diffusion_lora_trainer.py | 7 ++-
.../training/diffusion_training_service.py | 47 ++++++++++++++-----
studio/backend/models/training.py | 9 +++-
studio/backend/routes/training.py | 1 +
studio/frontend/src/features/images/api.ts | 3 ++
.../images/train/diffusion-charts.tsx | 47 ++++++++++---------
.../images/train/diffusion-train-panel.tsx | 12 +++--
8 files changed, 89 insertions(+), 43 deletions(-)
diff --git a/studio/backend/core/training/diffusion_dit_trainer.py b/studio/backend/core/training/diffusion_dit_trainer.py
index 5221425e4b..5776f87652 100644
--- a/studio/backend/core/training/diffusion_dit_trainer.py
+++ b/studio/backend/core/training/diffusion_dit_trainer.py
@@ -1157,8 +1157,11 @@ def _train_dit(cfg, spec, pairs, rng, device, weight_dtype, on_event, _check_sto
(loss / cfg.gradient_accumulation_steps).backward()
step_loss += float(loss.detach()) / cfg.gradient_accumulation_steps
+ grad_norm = None
if cfg.max_grad_norm and cfg.max_grad_norm > 0:
- torch.nn.utils.clip_grad_norm_(lora_params, cfg.max_grad_norm)
+ # clip_grad_norm_ returns the total PRE-clip norm: the health signal the UI
+ # charts (an exploding norm shows up here even while the clip caps the update).
+ grad_norm = float(torch.nn.utils.clip_grad_norm_(lora_params, cfg.max_grad_norm))
optimizer.step()
lr_sched.step()
@@ -1185,6 +1188,7 @@ def _train_dit(cfg, spec, pairs, rng, device, weight_dtype, on_event, _check_sto
loss = round(step_loss, 5),
avg_loss = round(running_loss / done, 5),
learning_rate = lr_sched.get_last_lr()[0],
+ grad_norm = round(grad_norm, 5) if grad_norm is not None else None,
samples_per_second = sps,
peak_memory_gb = peak_gb or None,
)
diff --git a/studio/backend/core/training/diffusion_lora_trainer.py b/studio/backend/core/training/diffusion_lora_trainer.py
index 7c7ca79d51..10b6cd89cd 100644
--- a/studio/backend/core/training/diffusion_lora_trainer.py
+++ b/studio/backend/core/training/diffusion_lora_trainer.py
@@ -509,8 +509,12 @@ def run_diffusion_lora_training(
# max_grad_norm <= 0 means "disable clipping" (the Studio payload sends 0.0 for that);
# passing 0.0 to clip_grad_norm_ would scale every gradient to zero (no learning).
+ grad_norm = None
if cfg.max_grad_norm and cfg.max_grad_norm > 0:
- torch.nn.utils.clip_grad_norm_(lora_params, cfg.max_grad_norm)
+ # The returned value is the total PRE-clip norm, reported to the UI chart.
+ grad_norm = float(
+ torch.nn.utils.clip_grad_norm_(lora_params, cfg.max_grad_norm)
+ )
optimizer.step()
lr_sched.step()
@@ -535,6 +539,7 @@ def run_diffusion_lora_training(
loss = round(step_loss, 5),
avg_loss = round(running_loss / done, 5),
learning_rate = lr_sched.get_last_lr()[0],
+ grad_norm = round(grad_norm, 5) if grad_norm is not None else None,
samples_per_second = samples_per_second,
peak_memory_gb = peak_gb or None,
)
diff --git a/studio/backend/core/training/diffusion_training_service.py b/studio/backend/core/training/diffusion_training_service.py
index fa44cceabe..2251038b78 100644
--- a/studio/backend/core/training/diffusion_training_service.py
+++ b/studio/backend/core/training/diffusion_training_service.py
@@ -67,6 +67,7 @@ def _idle_state() -> dict[str, Any]:
"loss": None,
"avg_loss": None,
"learning_rate": None,
+ "grad_norm": None,
"num_images": None,
"in_model_load": False,
"output_dir": None,
@@ -82,16 +83,21 @@ def _idle_state() -> dict[str, Any]:
"metric_steps": [],
"metric_loss": [],
"metric_lr": [],
+ "metric_grad_norm": [],
}
-def _append_metric(state: dict[str, Any], step: Any, loss: Any, lr: Any) -> None:
- """Append one (step, loss, lr) point to the bounded history arrays on ``state``.
+def _append_metric(
+ state: dict[str, Any], step: Any, loss: Any, lr: Any, grad_norm: Any = None
+) -> None:
+ """Append one (step, loss, lr, grad_norm) point to the bounded history arrays on
+ ``state``.
Only records finite, positive-step points (mirrors the LLM trainer, which logs history
only for step > 0 with a real loss). When the arrays hit ``_METRIC_CAP`` they are
decimated in place (keep every other point) so appends stay bounded without losing the
- curve's shape. lr may be None (kept as None so the LR series can be sparse)."""
+ curve's shape. lr / grad_norm may be None (kept as None so those series can be sparse
+ while staying index-aligned with ``steps``)."""
try:
istep = int(step)
except (TypeError, ValueError):
@@ -104,22 +110,34 @@ def _append_metric(state: dict[str, Any], step: Any, loss: Any, lr: Any) -> None
return
if floss != floss: # NaN guard
return
- flr: Optional[float]
- try:
- flr = float(lr) if lr is not None else None
- except (TypeError, ValueError):
- flr = None
+
+ def _opt_float(v: Any) -> Optional[float]:
+ try:
+ return float(v) if v is not None else None
+ except (TypeError, ValueError):
+ return None
+
+ flr = _opt_float(lr)
+ fgn = _opt_float(grad_norm)
steps = state["metric_steps"]
losses = state["metric_loss"]
lrs = state["metric_lr"]
+ gns = state["metric_grad_norm"]
if len(steps) >= _METRIC_CAP:
state["metric_steps"] = steps[::2]
state["metric_loss"] = losses[::2]
state["metric_lr"] = lrs[::2]
- steps, losses, lrs = state["metric_steps"], state["metric_loss"], state["metric_lr"]
+ state["metric_grad_norm"] = gns[::2]
+ steps, losses, lrs, gns = (
+ state["metric_steps"],
+ state["metric_loss"],
+ state["metric_lr"],
+ state["metric_grad_norm"],
+ )
steps.append(istep)
losses.append(floss)
lrs.append(flr)
+ gns.append(fgn)
class DiffusionTrainingService:
@@ -315,6 +333,7 @@ class DiffusionTrainingService:
loss = ev.get("loss", s["loss"]),
avg_loss = ev.get("avg_loss", s["avg_loss"]),
learning_rate = ev.get("learning_rate", s["learning_rate"]),
+ grad_norm = ev.get("grad_norm", s["grad_norm"]),
message = "Training...",
)
# Fold optional perf fields (emitted by the trainers) so the UI can show
@@ -323,8 +342,14 @@ class DiffusionTrainingService:
s["samples_per_second"] = ev.get("samples_per_second")
if ev.get("peak_memory_gb") is not None:
s["peak_memory_gb"] = ev.get("peak_memory_gb")
- # Retain a bounded (step, loss, lr) history for the live loss chart.
- _append_metric(s, ev.get("step"), ev.get("loss"), ev.get("learning_rate"))
+ # Retain a bounded (step, loss, lr, grad_norm) history for the live charts.
+ _append_metric(
+ s,
+ ev.get("step"),
+ ev.get("loss"),
+ ev.get("learning_rate"),
+ ev.get("grad_norm"),
+ )
elif etype == "complete":
# Reset in_model_load: a stop during model load emits complete without a
# preceding model_load_completed, which would otherwise leave a stale
diff --git a/studio/backend/models/training.py b/studio/backend/models/training.py
index 58a9779609..41452ddc89 100644
--- a/studio/backend/models/training.py
+++ b/studio/backend/models/training.py
@@ -753,12 +753,14 @@ class DiffusionTrainingStartResponse(BaseModel):
class DiffusionMetricHistory(BaseModel):
- """Paired step-indexed history arrays for the live training charts. ``lr`` entries may
- be null so a sparse learning-rate series still aligns with ``steps`` by index."""
+ """Paired step-indexed history arrays for the live training charts. ``lr`` and
+ ``grad_norm`` entries may be null so those sparse series still align with ``steps``
+ by index."""
steps: List[int] = Field(default_factory = list)
loss: List[float] = Field(default_factory = list)
lr: List[Optional[float]] = Field(default_factory = list)
+ grad_norm: List[Optional[float]] = Field(default_factory = list)
class DiffusionTrainingStatusResponse(BaseModel):
@@ -773,6 +775,9 @@ class DiffusionTrainingStatusResponse(BaseModel):
loss: Optional[float] = None
avg_loss: Optional[float] = None
learning_rate: Optional[float] = None
+ # Total pre-clip gradient norm from the last optimizer step (the training health
+ # signal the UI charts alongside the loss).
+ grad_norm: Optional[float] = None
num_images: Optional[int] = None
in_model_load: bool = False
output_dir: Optional[str] = None
diff --git a/studio/backend/routes/training.py b/studio/backend/routes/training.py
index 271abebd78..b16d95add0 100644
--- a/studio/backend/routes/training.py
+++ b/studio/backend/routes/training.py
@@ -1270,6 +1270,7 @@ async def diffusion_training_status(current_subject: str = Depends(get_current_s
steps = snap.pop("metric_steps", []),
loss = snap.pop("metric_loss", []),
lr = snap.pop("metric_lr", []),
+ grad_norm = snap.pop("metric_grad_norm", []),
)
return DiffusionTrainingStatusResponse(**snap, metric_history = metric_history)
diff --git a/studio/frontend/src/features/images/api.ts b/studio/frontend/src/features/images/api.ts
index bd6c09dd33..25e4f103e4 100644
--- a/studio/frontend/src/features/images/api.ts
+++ b/studio/frontend/src/features/images/api.ts
@@ -304,6 +304,8 @@ export interface DiffusionMetricHistory {
steps: number[];
loss: number[];
lr: Array;
+ // Total pre-clip gradient norm per step (the training health signal the charts show).
+ grad_norm?: Array;
}
// A snapshot of the current diffusion training job (GET /api/train/diffusion/status).
@@ -317,6 +319,7 @@ export interface DiffusionTrainingStatus {
loss: number | null;
avg_loss: number | null;
learning_rate: number | null;
+ grad_norm?: number | null;
num_images: number | null;
in_model_load: boolean;
output_dir: string | null;
diff --git a/studio/frontend/src/features/images/train/diffusion-charts.tsx b/studio/frontend/src/features/images/train/diffusion-charts.tsx
index daf762f056..7deb70f122 100644
--- a/studio/frontend/src/features/images/train/diffusion-charts.tsx
+++ b/studio/frontend/src/features/images/train/diffusion-charts.tsx
@@ -4,12 +4,13 @@
import { type ReactElement, useMemo } from "react";
import type { TrainingSeriesPoint } from "@/features/training";
-// The loss + LR cards are pure presentational (props only), so reuse them directly. We do
-// NOT reuse ChartsSection/ChartsContent: those also render Grad Norm and an Eval Loss card,
-// which are meaningless for diffusion LoRA training and showed as an empty card and an
-// "Evaluation not configured" placeholder. This is a diffusion-only two-card layout.
+// The loss + grad-norm cards are pure presentational (props only), so reuse them directly.
+// We do NOT reuse ChartsSection/ChartsContent: those also render an LR and an Eval Loss
+// card, which add little for diffusion LoRA training (the LR curve is the deterministic
+// schedule the user just picked; eval is not configured). This is a diffusion-only
+// two-card layout: Training Loss + Grad Norm (the actual training health signal).
// eslint-disable-next-line no-restricted-imports
-import { LearningRateChartCard } from "@/features/studio/sections/charts/learning-rate-chart-card";
+import { GradNormChartCard } from "@/features/studio/sections/charts/grad-norm-chart-card";
// eslint-disable-next-line no-restricted-imports
import { TrainingLossChartCard } from "@/features/studio/sections/charts/training-loss-chart-card";
// eslint-disable-next-line no-restricted-imports
@@ -43,16 +44,16 @@ function fullStepDomain(steps: number[]): [number, number] {
return [min, max];
}
-// A diffusion-only metrics view: just Training Loss and Learning Rate, side by side, with a
-// note under the loss card explaining why per-step loss looks noisy. Always renders both
-// cards (even with no data) so the Train tab can show them grayed before a run starts; the
-// parent applies the grayed treatment via a wrapper, so we never early-return null here.
+// A diffusion-only metrics view: Training Loss and Grad Norm, side by side, with a note
+// under the loss card explaining why per-step loss looks noisy. Always renders both cards
+// (even with no data) so the parent can decide when to mount them; we never early-return
+// null here.
export function DiffusionCharts({
lossHistory,
- lrHistory,
+ gradNormHistory,
}: {
lossHistory: TrainingSeriesPoint[];
- lrHistory: TrainingSeriesPoint[];
+ gradNormHistory: TrainingSeriesPoint[];
}): ReactElement {
const lossItems = useMemo(() => toLossItems(lossHistory), [lossHistory]);
const smoothed = useMemo(
@@ -73,23 +74,23 @@ export function DiffusionCharts({
[reducedLoss],
);
- const lrData = useMemo(
+ const gradData = useMemo(
() =>
compressSeries(
- lrHistory
+ gradNormHistory
.filter((p) => Number.isFinite(p.value))
- .map((p) => ({ step: p.step, lr: p.value, displayLr: p.value })),
+ .map((p) => ({ step: p.step, gradNorm: p.value, displayGradNorm: p.value })),
MAX_RENDER_POINTS,
),
- [lrHistory],
+ [gradNormHistory],
);
const steps = useMemo(() => {
const set = new Set();
for (const p of lossData) set.add(p.step);
- for (const p of lrData) set.add(p.step);
+ for (const p of gradData) set.add(p.step);
return Array.from(set).sort((a, b) => a - b);
- }, [lossData, lrData]);
+ }, [lossData, gradData]);
const stepDomain = useMemo(() => fullStepDomain(steps), [steps]);
const xAxisTicks = useMemo(
@@ -101,9 +102,9 @@ export function DiffusionCharts({
() => buildYDomain(lossData.flatMap((p) => [p.displayLoss, p.displaySmoothed])),
[lossData],
);
- const lrDomain = useMemo(
- () => buildYDomain(lrData.map((p) => p.displayLr)),
- [lrData],
+ const gradDomain = useMemo(
+ () => buildYDomain(gradData.map((p) => p.displayGradNorm)),
+ [gradData],
);
const avgRaw =
@@ -131,9 +132,9 @@ export function DiffusionCharts({
the smoothed line for the trend, not the raw jitter.
- ({ step, value: h.loss[i] })).filter((p) => p.value != null);
}, [status?.metric_history]);
- const lrHistory: TrainingSeriesPoint[] = useMemo(() => {
+ const gradNormHistory: TrainingSeriesPoint[] = useMemo(() => {
const h = status?.metric_history;
- if (!h) return [];
+ if (!h?.grad_norm) return [];
return h.steps
- .map((step, i) => ({ step, value: h.lr[i] }))
+ .map((step, i) => ({ step, value: h.grad_norm?.[i] ?? null }))
.filter((p): p is TrainingSeriesPoint => p.value != null);
}, [status?.metric_history]);
@@ -1029,7 +1029,9 @@ export function DiffusionTrainPanel({
<>
- {status?.status}
+
+ {status?.status === "completed" ? "Training complete \u{1F389}" : status?.status}
+
{(status?.total_steps ?? 0) > 0
? `${status?.step}/${status?.total_steps} steps`
@@ -1073,7 +1075,7 @@ export function DiffusionTrainPanel({
)}
-
+
>
)}