Further CPU Experimental Changes

server/services/collectors/bcache.js

@@ -6,6 +6,7 @@ import fs from 'fs'
 import path from 'path'
 import { CollectorPlugin } from './plugin.js'
 import { registerChart } from '../../../shared/metrics.js'
+import { readFileBuf } from '../../utils/fd-cache.js'
 
 export function isBcacheEnabled() {
   const v = process.env.PEARDATA_BCACHE
@@ -15,11 +16,8 @@ export function isBcacheEnabled() {
 }
 
 function readNum(p) {
-  try {
-    return Number(fs.readFileSync(p, 'utf8').trim()) || 0
-  } catch {
-    return 0
-  }
+  const raw = readFileBuf(p)
+  return raw ? Number(raw.trim()) || 0 : 0
 }
 
 export class BcacheCollector extends CollectorPlugin {

server/services/collectors/cgroups.js

@@ -20,6 +20,7 @@ import {
 } from '../../../shared/metrics.js'
 import { resolveContainerLabel } from '../../../shared/container-names.js'
 import { loadContainerNameMap, resolveDockerSocket } from './docker.js'
+import { readFileBuf } from '../../utils/fd-cache.js'
 import logger from '../../utils/logger.js'
 
 const log = logger.child('cgroups')
@@ -37,11 +38,7 @@ function maxCgroups() {
 }
 
 function readFile(p) {
-  try {
-    return fs.readFileSync(p, 'utf8')
-  } catch {
-    return null
-  }
+  return readFileBuf(p)
 }
 
 function cgroupRoot() {

server/services/collectors/dmcache.js

@@ -10,6 +10,7 @@ import fs from 'fs'
 import path from 'path'
 import { CollectorPlugin } from './plugin.js'
 import { registerChart } from '../../../shared/metrics.js'
+import { readFileBuf } from '../../utils/fd-cache.js'
 import { execFile } from '../../utils/exec.js'
 import logger from '../../utils/logger.js'
 
@@ -39,11 +40,7 @@ export function isDmcacheEnabled() {
 }
 
 function readFile(p) {
-  try {
-    return fs.readFileSync(p, 'utf8')
-  } catch {
-    return null
-  }
+  return readFileBuf(p)
 }
 
 /**

server/services/collectors/docker.js

@@ -16,6 +16,7 @@ import net from 'net'
 import os from 'os'
 import { EventEmitter } from 'events'
 import { execFile } from '../../utils/exec.js'
+import { readFileBuf } from '../../utils/fd-cache.js'
 import {
   SAMPLE_INTERVAL_MS,
   registerChart,
@@ -59,11 +60,7 @@ export function resolveDockerSocket(preferred) {
 }
 
 function readFile(p) {
-  try {
-    return fs.readFileSync(p, 'utf8')
-  } catch {
-    return null
-  }
+  return readFileBuf(p)
 }
 
 function bytesToMiB(n) {

server/services/collectors/ebpf.js

@@ -16,6 +16,7 @@ import {
   SAMPLE_INTERVAL_MS,
   registerChart,
 } from '../../../shared/metrics.js'
+import { readFileCached, readFileBuf } from '../../utils/fd-cache.js'
 import { extractHelper, hasEmbeddedHelper } from '../../native/extract-helper.js'
 import logger from '../../utils/logger.js'
 
@@ -202,13 +203,12 @@ export class EbpfCollector extends EventEmitter {
   _readVm() {
     /** @type {Record<string, number>} */
     const out = {}
-    try {
-      for (const line of fs.readFileSync('/proc/vmstat', 'utf8').split('\n')) {
+    const raw = readFileCached('/proc/vmstat')
+    if (raw) {
+      for (const line of raw.split('\n')) {
         const [k, v] = line.trim().split(/\s+/)
         if (k) out[k] = Number(v) || 0
       }
-    } catch {
-      // ignore
     }
     return out
   }
@@ -228,30 +228,27 @@ export class EbpfCollector extends EventEmitter {
     const den = dHit + dMiss
 
     let fileNr = [0, 0]
-    try {
-      const parts = fs.readFileSync('/proc/sys/fs/file-nr', 'utf8').trim().split(/\s+/)
+    const fileNrRaw = readFileCached('/proc/sys/fs/file-nr')
+    if (fileNrRaw) {
+      const parts = fileNrRaw.trim().split(/\s+/)
       fileNr = [Number(parts[0]) || 0, Number(parts[2]) || 0]
-    } catch {
-      // ignore
     }
 
     let forks = 0
     let ctxt = 0
-    try {
-      for (const line of fs.readFileSync('/proc/stat', 'utf8').split('\n')) {
+    const statRaw = readFileCached('/proc/stat')
+    if (statRaw) {
+      for (const line of statRaw.split('\n')) {
         if (line.startsWith('processes ')) forks = Number(line.slice(10)) || 0
         if (line.startsWith('ctxt ')) ctxt = Number(line.slice(5)) || 0
       }
-    } catch {
-      // ignore
     }
 
     let tcp = 0
-    try {
-      const m = fs.readFileSync('/proc/net/sockstat', 'utf8').match(/TCP:\s+inuse\s+(\d+)/)
+    const sockRaw = readFileCached('/proc/net/sockstat')
+    if (sockRaw) {
+      const m = sockRaw.match(/TCP:\s+inuse\s+(\d+)/)
       if (m) tcp = Number(m[1]) || 0
-    } catch {
-      // ignore
     }
 
     const batch = [

server/services/collectors/fs-stats.js

@@ -11,6 +11,7 @@ import path from 'path'
 import os from 'os'
 import { CollectorPlugin } from './plugin.js'
 import { registerChart } from '../../../shared/metrics.js'
+import { readFileBuf } from '../../utils/fd-cache.js'
 import logger from '../../utils/logger.js'
 
 const log = logger.child('fs-stats')
@@ -23,11 +24,7 @@ export function isFsStatsEnabled() {
 }
 
 function readFile(p) {
-  try {
-    return fs.readFileSync(p, 'utf8')
-  } catch {
-    return null
-  }
+  return readFileBuf(p)
 }
 
 function readNum(p) {

server/services/collectors/mdstat.js

@@ -9,6 +9,7 @@ import fs from 'fs'
 import os from 'os'
 import { EventEmitter } from 'events'
 import { SAMPLE_INTERVAL_MS, registerChart } from '../../../shared/metrics.js'
+import { readFileBuf } from '../../utils/fd-cache.js'
 import logger from '../../utils/logger.js'
 
 const log = logger.child('mdstat')
@@ -31,11 +32,7 @@ const CHART_HEALTH = {
 }
 
 function readFile(p) {
-  try {
-    return fs.readFileSync(p, 'utf8')
-  } catch {
-    return null
-  }
+  return readFileBuf(p)
 }
 
 /**

server/services/collectors/processes.js

@@ -17,6 +17,7 @@ import path from 'path'
 import os from 'os'
 import { EventEmitter } from 'events'
 import { SAMPLE_INTERVAL_MS, registerChart } from '../../../shared/metrics.js'
+import { readFileBuf } from '../../utils/fd-cache.js'
 import logger from '../../utils/logger.js'
 
 const log = logger.child('processes')
@@ -50,6 +51,10 @@ function sanitizeDim(name) {
   return s || 'unknown'
 }
 
+const PROC_EXTRA_CACHE = new Map()
+const PROC_EXTRA_TICK = 5
+let procTickCount = 0
+
 /**
  * @returns {Array<{ pid: number, name: string, utime: number, stime: number, rssPages: number, threads: number, readBytes: number|null, writeBytes: number|null }>|null}
  */
@@ -61,47 +66,52 @@ export function listProcStats() {
   } catch {
     return null
   }
+  procTickCount = (procTickCount + 1) % PROC_EXTRA_TICK
+  const readExtra = procTickCount === 0
+
   /** @type {Array<{ pid: number, name: string, utime: number, stime: number, rssPages: number, threads: number, readBytes: number|null, writeBytes: number|null }>} */
   const out = []
   for (const ent of dirs) {
     if (!/^\d+$/.test(ent)) continue
     const pid = Number(ent)
-    let raw
-    try {
-      raw = fs.readFileSync(path.join('/proc', ent, 'stat'), 'utf8')
-    } catch {
-      continue
-    }
+    const raw = readFileBuf(path.join('/proc', ent, 'stat'))
+    if (!raw) continue
     const open = raw.indexOf('(')
     const close = raw.lastIndexOf(')')
     if (open < 0 || close < open) continue
     const name = raw.slice(open + 1, close)
     const rest = raw.slice(close + 2).split(/\s+/)
-    // fields after comm: state(0) … utime(11) stime(12) … rss(21)
     const utime = Number(rest[11])
     const stime = Number(rest[12])
     const rssPages = Number(rest[21])
     if (!Number.isFinite(utime) || !Number.isFinite(stime)) continue
 
     let threads = 0
-    try {
-      const status = fs.readFileSync(path.join('/proc', ent, 'status'), 'utf8')
-      const m = status.match(/^Threads:\s*(\d+)/m)
-      if (m) threads = Number(m[1]) || 0
-    } catch {
-      // ignore
-    }
-
     let readBytes = null
     let writeBytes = null
-    try {
-      const ioRaw = fs.readFileSync(path.join('/proc', ent, 'io'), 'utf8')
+
+    if (readExtra) {
+      const status = readFileBuf(path.join('/proc', ent, 'status'))
+      if (status) {
+        const m = status.match(/^Threads:\s*(\d+)/m)
+        if (m) threads = Number(m[1]) || 0
+      }
+      const ioRaw = readFileBuf(path.join('/proc', ent, 'io'))
+      if (ioRaw) {
         const rb = ioRaw.match(/^read_bytes:\s*(\d+)/m)
         const wb = ioRaw.match(/^write_bytes:\s*(\d+)/m)
         if (rb) readBytes = Number(rb[1]) || 0
         if (wb) writeBytes = Number(wb[1]) || 0
-    } catch {
-      // unreadable for this pid
+      }
+    }
+    const cached = PROC_EXTRA_CACHE.get(pid)
+    if (cached) {
+      if (threads === 0) threads = cached.threads
+      if (readBytes === null) readBytes = cached.readBytes
+      if (writeBytes === null) writeBytes = cached.writeBytes
+    }
+    if (readExtra || !cached) {
+      PROC_EXTRA_CACHE.set(pid, { threads, readBytes, writeBytes })
     }
 
     out.push({

server/services/collectors/sensors.js

@@ -14,6 +14,7 @@ import {
   makeSensorTempChart,
   makeThermalZoneChart,
 } from '../../../shared/metrics.js'
+import { readFileBuf } from '../../utils/fd-cache.js'
 import logger from '../../utils/logger.js'
 
 const log = logger.child('sensors')
@@ -26,11 +27,7 @@ export function isSensorsEnabled() {
 }
 
 function readFile(p) {
-  try {
-    return fs.readFileSync(p, 'utf8')
-  } catch {
-    return null
-  }
+  return readFileBuf(p)
 }
 
 function makeSensorFanChart(chip, label) {

server/services/collectors/sockets.js

@@ -6,6 +6,7 @@ import fs from 'fs'
 import os from 'os'
 import { EventEmitter } from 'events'
 import { SAMPLE_INTERVAL_MS, registerChart } from '../../../shared/metrics.js'
+import { readFileBuf } from '../../utils/fd-cache.js'
 import logger from '../../utils/logger.js'
 
 const log = logger.child('sockets')
@@ -42,12 +43,8 @@ function countTcp(file) {
     syn_recv: 0,
     other: 0,
   }
-  let raw
-  try {
-    raw = fs.readFileSync(file, 'utf8')
-  } catch {
-    return counts
-  }
+  const raw = readFileBuf(file)
+  if (!raw) return counts
   for (const line of raw.split('\n').slice(1)) {
     const parts = line.trim().split(/\s+/)
     if (parts.length < 4) continue
@@ -60,11 +57,9 @@ function countTcp(file) {
 }
 
 function countUdp(file) {
-  try {
-    return Math.max(0, fs.readFileSync(file, 'utf8').trim().split('\n').length - 1)
-  } catch {
-    return 0
-  }
+  const raw = readFileBuf(file)
+  if (!raw) return 0
+  return Math.max(0, raw.trim().split('\n').length - 1)
 }
 
 export class SocketsCollector extends EventEmitter {

server/utils/fd-cache.js

@@ -1,6 +1,7 @@
 import fs from 'fs'
 
 const READ_BUF = Buffer.alloc(65536)
+const SMALL_BUF = Buffer.alloc(8192)
 const fdCache = new Map()
 
 export function readFileCached(path) {
@@ -24,6 +25,25 @@ export function readFileCached(path) {
   }
 }
 
+/**
+ * Read a file using the shared small buffer, no FD caching.
+ * Good for dynamic paths (per-PID, per-cgroup) where open+close each tick is acceptable
+ * but Buffer allocation is not.
+ */
+export function readFileBuf(path) {
+  try {
+    const fd = fs.openSync(path, 'r')
+    try {
+      const bytes = fs.readSync(fd, SMALL_BUF, 0, SMALL_BUF.length, 0)
+      return SMALL_BUF.toString('utf8', 0, bytes)
+    } finally {
+      fs.closeSync(fd)
+    }
+  } catch {
+    return null
+  }
+}
+
 export function closeFdCache() {
   for (const [path, entry] of fdCache) {
     if (entry) {