Add initial support for monitoring GPUs on Linux (prometheus#1998)

Expose GPU metrics using `sysfs/drm`.
`amdgpu` is the only driver which exposes this information through DRM.

Signed-off-by: Siavash Safi <siavash.safi@gmail.com>

collector/drm_linux.go

@@ -0,0 +1,143 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !nogpu
+
+package collector
+
+import (
+	"fmt"
+
+	"github.com/go-kit/log"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/procfs/sysfs"
+)
+
+const (
+	drmCollectorSubsystem = "drm"
+)
+
+type drmCollector struct {
+	fs                    sysfs.FS
+	logger                log.Logger
+	CardInfo              *prometheus.Desc
+	GPUBusyPercent        *prometheus.Desc
+	MemoryGTTSize         *prometheus.Desc
+	MemoryGTTUsed         *prometheus.Desc
+	MemoryVisibleVRAMSize *prometheus.Desc
+	MemoryVisibleVRAMUsed *prometheus.Desc
+	MemoryVRAMSize        *prometheus.Desc
+	MemoryVRAMUsed        *prometheus.Desc
+}
+
+func init() {
+	registerCollector("drm", defaultDisabled, NewDrmCollector)
+}
+
+// NewDrmCollector returns a new Collector exposing /sys/class/drm/card?/device stats.
+func NewDrmCollector(logger log.Logger) (Collector, error) {
+	fs, err := sysfs.NewFS(*sysPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open sysfs: %w", err)
+	}
+
+	return &drmCollector{
+		fs:     fs,
+		logger: logger,
+		CardInfo: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, drmCollectorSubsystem, "card_info"),
+			"Card information",
+			[]string{"card", "memory_vendor", "power_performance_level", "unique_id", "vendor"}, nil,
+		),
+		GPUBusyPercent: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, drmCollectorSubsystem, "gpu_busy_percent"),
+			"How busy the GPU is as a percentage.",
+			[]string{"card"}, nil,
+		),
+		MemoryGTTSize: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, drmCollectorSubsystem, "memory_gtt_size_bytes"),
+			"The size of the graphics translation table (GTT) block in bytes.",
+			[]string{"card"}, nil,
+		),
+		MemoryGTTUsed: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, drmCollectorSubsystem, "memory_gtt_used_bytes"),
+			"The used amount of the graphics translation table (GTT) block in bytes.",
+			[]string{"card"}, nil,
+		),
+		MemoryVisibleVRAMSize: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, drmCollectorSubsystem, "memory_vis_vram_size_bytes"),
+			"The size of visible VRAM in bytes.",
+			[]string{"card"}, nil,
+		),
+		MemoryVisibleVRAMUsed: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, drmCollectorSubsystem, "memory_vis_vram_used_bytes"),
+			"The used amount of visible VRAM in bytes.",
+			[]string{"card"}, nil,
+		),
+		MemoryVRAMSize: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, drmCollectorSubsystem, "memory_vram_size_bytes"),
+			"The size of VRAM in bytes.",
+			[]string{"card"}, nil,
+		),
+		MemoryVRAMUsed: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, drmCollectorSubsystem, "memory_vram_used_bytes"),
+			"The used amount of VRAM in bytes.",
+			[]string{"card"}, nil,
+		),
+	}, nil
+}
+
+func (c *drmCollector) Update(ch chan<- prometheus.Metric) error {
+	if err := c.updateAMDCards(ch); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (c *drmCollector) updateAMDCards(ch chan<- prometheus.Metric) error {
+	vendor := "amd"
+	stats, err := c.fs.ClassDRMCardAMDGPUStats()
+	if err != nil {
+		return err
+	}
+
+	for _, s := range stats {
+		ch <- prometheus.MustNewConstMetric(
+			c.CardInfo, prometheus.GaugeValue, 1,
+			s.Name, s.MemoryVRAMVendor, s.PowerDPMForcePerformanceLevel, s.UniqueID, vendor)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.GPUBusyPercent, prometheus.GaugeValue, float64(s.GPUBusyPercent), s.Name)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.MemoryGTTSize, prometheus.GaugeValue, float64(s.MemoryGTTSize), s.Name)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.MemoryGTTUsed, prometheus.GaugeValue, float64(s.MemoryGTTUsed), s.Name)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.MemoryVRAMSize, prometheus.GaugeValue, float64(s.MemoryVRAMSize), s.Name)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.MemoryVRAMUsed, prometheus.GaugeValue, float64(s.MemoryVRAMUsed), s.Name)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.MemoryVisibleVRAMSize, prometheus.GaugeValue, float64(s.MemoryVisibleVRAMSize), s.Name)
+
+		ch <- prometheus.MustNewConstMetric(
+			c.MemoryVisibleVRAMUsed, prometheus.GaugeValue, float64(s.MemoryVisibleVRAMUsed), s.Name)
+	}
+
+	return nil
+}