Top: one beat — graphs, numbers and the process table change on the same tick

Graphs stepped once a history point (1 s at a 5 min window) while the numbers changed every
tick; they now slide a fraction of a column each tick. The process table (and the GPU boxes,
MHz and watts it carries) was polled on its own timer; it is now read per sample and committed
with it. GPU clients are walked every sample, and the 1–2 s floors on the gallery, Network,
Docker and ZFS ARC live views are gone.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/metrics/gpu.go

@@ -84,9 +84,9 @@ type gpuDev struct {
 type gpuState struct {
 	devs     []*gpuDev
 	listedAt time.Time
-	clients  map[string]clientPrev // device key + client id → engine totals at the previous scan
-	last     []drmFD               // the newest client walk, reused between walks
-	scanAt   time.Time
+	clients  map[string]clientPrev  // device key + client id → engine totals at the previous scan
+	last     []drmFD                // the newest client walk
+	scan     func() ([]drmFD, bool) // the walk; nil is scanClients (tests stand a fake list in)
 	helper   *drmHelper
 	ok       bool // the last walk saw every process
 }
@@ -96,8 +96,7 @@ type clientPrev struct {
 	at time.Time
 }
 
-const gpuRelist = time.Minute    // how often the card list is re-read: hotplug is rare, the readdir is cheap
-const gpuScanEvery = time.Second // engine shares over less than this are noise
+const gpuRelist = time.Minute // how often the card list is re-read: hotplug is rare, the readdir is cheap
 
 // gpus is the GPU section of a sample. cpuTemp stands in for an integrated GPU's
 // temperature: it is the same die.
@@ -112,10 +111,13 @@ func (c *Collector) gpus(now time.Time, cpuTemp float64) []GPU {
 	if g.clients == nil {
 		g.clients = map[string]clientPrev{}
 	}
-	if g.scanAt.IsZero() || now.Sub(g.scanAt) >= gpuScanEvery {
-		g.last, g.ok = c.scanClients()
-		g.scanAt = now
+	// The clients are read on every sample, like everything else in it: their engine shares
+	// move on the same tick as the device's own numbers, at whatever rate is set.
+	scan := c.scanClients
+	if g.scan != nil {
+		scan = g.scan
 	}
+	g.last, g.ok = scan()
 	out := make([]GPU, 0, len(g.devs))
 	live := map[string]bool{}
 	for _, d := range g.devs {

internal/metrics/gpu_test.go

@@ -61,7 +61,7 @@ func TestGPUClientsShare(t *testing.T) {
 	c.gpu.clients = map[string]clientPrev{}
 	t0 := time.Now()
 	c.gpu.last = []drmFD{{PID: 7, Comm: "ffmpeg", Info: fdinfoA}}
-	c.gpu.scanAt = t0 // no walk: the fake list stands
+	c.gpu.scan = func() ([]drmFD, bool) { return c.gpu.last, true } // no walk: the fake list stands
 	first := c.gpus(t0, 40)
 	if len(first) != 1 || len(first[0].Clients) != 1 || first[0].Clients[0].Usage != 0 {
 		t.Fatalf("first pass: %+v", first)
@@ -73,7 +73,6 @@ func TestGPUClientsShare(t *testing.T) {
 	later = replace(later, "drm-engine-render:	1000000000 ns", "drm-engine-render:	1500000000 ns")
 	later = replace(later, "drm-engine-video:	2000000000 ns", "drm-engine-video:	4000000000 ns")
 	c.gpu.last = []drmFD{{PID: 7, Comm: "ffmpeg", Info: later}}
-	c.gpu.scanAt = t0.Add(time.Second)
 	got := c.gpus(t0.Add(time.Second), 40)
 	cl := got[0].Clients[0]
 	if cl.Engines["render"] != 50 || cl.Engines["video"] != 100 || cl.Usage != 100 {