From 38bc1b413d1762280aaf6305c24bd5d3be5c1bec Mon Sep 17 00:00:00 2001
From: Fabian Meumertzheim <fabian@meumertzhe.im>
Date: Thu, 23 Jan 2025 15:59:24 +0100
Subject: [PATCH] cli: Make the CLI cgroups-aware

Honoring cgroups limits on CPUs is useful when running `bb explain` in a workflow, such as in the "Compare" Bazel button.
---
 MODULE.bazel     |  1 +
 cli/cmd/bb/BUILD |  1 +
 cli/cmd/bb/bb.go |  3 +++
 deps.bzl         | 12 ++++++++++++
 go.mod           |  1 +
 go.sum           |  4 ++++
 6 files changed, 22 insertions(+)

diff --git a/MODULE.bazel b/MODULE.bazel
index 74864c3d693..97500616d67 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -394,6 +394,7 @@ use_repo(
     "org_golang_x_time",
     "org_golang_x_tools",
     "org_uber_go_atomic",
+    "org_uber_go_automaxprocs",
 )
 
 # Note that this is 'rules_nodejs-core'
diff --git a/cli/cmd/bb/BUILD b/cli/cmd/bb/BUILD
index 8e90f77b9c2..fb017769050 100644
--- a/cli/cmd/bb/BUILD
+++ b/cli/cmd/bb/BUILD
@@ -25,6 +25,7 @@ go_library(
         "//cli/watcher",
         "//server/util/rlimit",
         "//server/util/status",
+        "@org_uber_go_automaxprocs//:automaxprocs",
     ],
 )
 
diff --git a/cli/cmd/bb/bb.go b/cli/cmd/bb/bb.go
index 307b49ee343..b4729f4e2d0 100644
--- a/cli/cmd/bb/bb.go
+++ b/cli/cmd/bb/bb.go
@@ -22,6 +22,9 @@ import (
 	"github.com/buildbuddy-io/buildbuddy/server/util/status"
 
 	sidecarmain "github.com/buildbuddy-io/buildbuddy/cli/cmd/sidecar"
+
+	// Make GOMAXPROCS cgroups-aware.
+	_ "go.uber.org/automaxprocs"
 )
 
 var (
diff --git a/deps.bzl b/deps.bzl
index 4cd2da336ff..ad39e12b671 100644
--- a/deps.bzl
+++ b/deps.bzl
@@ -3954,6 +3954,12 @@ def install_go_mod_dependencies(workspace_name = "buildbuddy"):
         sum = "h1:xoIK0ctDddBMnc74udxJYBqlo9Ylnsp1waqjLsnef20=",
         version = "v0.0.0-20190930134022-aa0246cd15f7",
     )
+    go_repository(
+        name = "com_github_prashantv_gostub",
+        importpath = "github.com/prashantv/gostub",
+        sum = "h1:BTyx3RfQjRHnUWaGF9oQos79AlQ5k8WNktv7VGvVH4g=",
+        version = "v1.1.0",
+    )
     go_repository(
         name = "com_github_prometheus_client_golang",
         build_directives = [
@@ -6353,6 +6359,12 @@ def install_go_mod_dependencies(workspace_name = "buildbuddy"):
         sum = "h1:ZvwS0R+56ePWxUNi+Atn9dWONBPp/AUETXlHW0DxSjE=",
         version = "v1.11.0",
     )
+    go_repository(
+        name = "org_uber_go_automaxprocs",
+        importpath = "go.uber.org/automaxprocs",
+        sum = "h1:O3y2/QNTOdbF+e/dpXNNW7Rx2hZ4sTIPyybbxyNqTUs=",
+        version = "v1.6.0",
+    )
     go_repository(
         name = "org_uber_go_goleak",
         importpath = "go.uber.org/goleak",
diff --git a/go.mod b/go.mod
index d5e8c60aecc..4c3d32fefdb 100644
--- a/go.mod
+++ b/go.mod
@@ -136,6 +136,7 @@ require (
 	go.opentelemetry.io/otel/sdk v1.29.0
 	go.opentelemetry.io/otel/trace v1.31.0
 	go.uber.org/atomic v1.11.0
+	go.uber.org/automaxprocs v1.6.0
 	golang.org/x/crypto v0.31.0
 	golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56
 	golang.org/x/mod v0.20.0
diff --git a/go.sum b/go.sum
index 6d0fb269a93..a65be883e31 100644
--- a/go.sum
+++ b/go.sum
@@ -1401,6 +1401,8 @@ github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c/go.mod h1:Om
 github.com/power-devops/perfstat v0.0.0-20221212215047-62379fc7944b h1:0LFwY6Q3gMACTjAbMZBjXAqTOzOwFaj2Ld6cjeQ7Rig=
 github.com/power-devops/perfstat v0.0.0-20221212215047-62379fc7944b/go.mod h1:OmDBASR4679mdNQnz2pUhc2G8CO2JrUAVFDRBDP/hJE=
 github.com/pquerna/cachecontrol v0.0.0-20171018203845-0dec1b30a021/go.mod h1:prYjPmNq4d1NPVmpShWobRqXY3q7Vp+80DqgxxUrUIA=
+github.com/prashantv/gostub v1.1.0 h1:BTyx3RfQjRHnUWaGF9oQos79AlQ5k8WNktv7VGvVH4g=
+github.com/prashantv/gostub v1.1.0/go.mod h1:A5zLQHz7ieHGG7is6LLXLz7I8+3LZzsrV0P1IAHhP5U=
 github.com/prometheus/client_golang v0.0.0-20180209125602-c332b6f63c06/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
 github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
 github.com/prometheus/client_golang v0.9.3/go.mod h1:/TN21ttK/J9q6uSwhBd54HahCDft0ttaMvbicHlPoso=
@@ -1738,6 +1740,8 @@ go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
 go.uber.org/atomic v1.10.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0=
 go.uber.org/atomic v1.11.0 h1:ZvwS0R+56ePWxUNi+Atn9dWONBPp/AUETXlHW0DxSjE=
 go.uber.org/atomic v1.11.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0=
+go.uber.org/automaxprocs v1.6.0 h1:O3y2/QNTOdbF+e/dpXNNW7Rx2hZ4sTIPyybbxyNqTUs=
+go.uber.org/automaxprocs v1.6.0/go.mod h1:ifeIMSnPZuznNm6jmdzmU3/bfk01Fe2fotchwEFJ8r8=
 go.uber.org/goleak v1.1.10/go.mod h1:8a7PlsEVH3e/a/GLqe5IIrQx6GzcnRmZEufDUTk4A7A=
 go.uber.org/goleak v1.1.11/go.mod h1:cwTWslyiVhfpKIDGSZEM2HlOvcqm+tG4zioyIeLoqMQ=
 go.uber.org/goleak v1.1.12/go.mod h1:cwTWslyiVhfpKIDGSZEM2HlOvcqm+tG4zioyIeLoqMQ=