Merge "Create a highmem pool and put metalava into it"
diff --git a/android/config.go b/android/config.go
index b13da7f..f907de6 100644
--- a/android/config.go
+++ b/android/config.go
@@ -827,6 +827,10 @@
 	return Bool(c.productVariables.UseRBE)
 }
 
+func (c *config) UseRemoteBuild() bool {
+	return c.UseGoma() || c.UseRBE()
+}
+
 func (c *config) RunErrorProne() bool {
 	return c.IsEnvTrue("RUN_ERROR_PRONE")
 }
diff --git a/android/defs.go b/android/defs.go
index 4890c66..5c815e6 100644
--- a/android/defs.go
+++ b/android/defs.go
@@ -99,6 +99,9 @@
 
 	// Used only when USE_GOMA=true is set, to restrict non-goma jobs to the local parallelism value
 	localPool = blueprint.NewBuiltinPool("local_pool")
+
+	// Used for processes that need significant RAM to ensure there are not too many running in parallel.
+	highmemPool = blueprint.NewBuiltinPool("highmem_pool")
 )
 
 func init() {
diff --git a/android/module.go b/android/module.go
index 2662e2a..4a72889 100644
--- a/android/module.go
+++ b/android/module.go
@@ -1351,7 +1351,7 @@
 func (m *moduleContext) Rule(pctx PackageContext, name string, params blueprint.RuleParams,
 	argNames ...string) blueprint.Rule {
 
-	if (m.config.UseGoma() || m.config.UseRBE()) && params.Pool == nil {
+	if m.config.UseRemoteBuild() && params.Pool == nil {
 		// When USE_GOMA=true or USE_RBE=true are set and the rule is not supported by goma/RBE, restrict
 		// jobs to the local parallelism value
 		params.Pool = localPool
diff --git a/android/package_ctx.go b/android/package_ctx.go
index a228910..6350667 100644
--- a/android/package_ctx.go
+++ b/android/package_ctx.go
@@ -109,7 +109,7 @@
 		if len(ctx.errors) > 0 {
 			return params, ctx.errors[0]
 		}
-		if (ctx.Config().UseGoma() || ctx.Config().UseRBE()) && params.Pool == nil {
+		if ctx.Config().UseRemoteBuild() && params.Pool == nil {
 			// When USE_GOMA=true or USE_RBE=true are set and the rule is not supported by
 			// goma/RBE, restrict jobs to the local parallelism value
 			params.Pool = localPool
diff --git a/android/rule_builder.go b/android/rule_builder.go
index 6f04672..928ba53 100644
--- a/android/rule_builder.go
+++ b/android/rule_builder.go
@@ -33,6 +33,8 @@
 	temporariesSet map[WritablePath]bool
 	restat         bool
 	sbox           bool
+	highmem        bool
+	remoteable     RemoteRuleSupports
 	sboxOutDir     WritablePath
 	missingDeps    []string
 }
@@ -87,6 +89,19 @@
 	return r
 }
 
+// HighMem marks the rule as a high memory rule, which will limit how many run in parallel with other high memory
+// rules.
+func (r *RuleBuilder) HighMem() *RuleBuilder {
+	r.highmem = true
+	return r
+}
+
+// Remoteable marks the rule as supporting remote execution.
+func (r *RuleBuilder) Remoteable(supports RemoteRuleSupports) *RuleBuilder {
+	r.remoteable = supports
+	return r
+}
+
 // Sbox marks the rule as needing to be wrapped by sbox. The WritablePath should point to the output
 // directory that sbox will wipe. It should not be written to by any other rule. sbox will ensure
 // that all outputs have been written, and will discard any output files that were not specified.
@@ -401,6 +416,17 @@
 		rspFileContent = "$in"
 	}
 
+	var pool blueprint.Pool
+	if ctx.Config().UseGoma() && r.remoteable&SUPPORTS_GOMA != 0 {
+		// When USE_GOMA=true is set and the rule is supported by goma, allow jobs to run outside the local pool.
+	} else if ctx.Config().UseRBE() && r.remoteable&SUPPORTS_RBE != 0 {
+		// When USE_GOMA=true is set and the rule is supported by RBE, allow jobs to run outside the local pool.
+	} else if r.highmem {
+		pool = highmemPool
+	} else if ctx.Config().UseRemoteBuild() {
+		pool = localPool
+	}
+
 	ctx.Build(pctx, BuildParams{
 		Rule: ctx.Rule(pctx, name, blueprint.RuleParams{
 			Command:        commandString,
@@ -408,6 +434,7 @@
 			Restat:         r.restat,
 			Rspfile:        rspFile,
 			RspfileContent: rspFileContent,
+			Pool:           pool,
 		}),
 		Inputs:          rspFileInputs,
 		Implicits:       r.Inputs(),
diff --git a/android/singleton.go b/android/singleton.go
index 91268ad..45a9b82 100644
--- a/android/singleton.go
+++ b/android/singleton.go
@@ -128,7 +128,7 @@
 }
 
 func (s *singletonContextAdaptor) Rule(pctx PackageContext, name string, params blueprint.RuleParams, argNames ...string) blueprint.Rule {
-	if (s.Config().UseGoma() || s.Config().UseRBE()) && params.Pool == nil {
+	if s.Config().UseRemoteBuild() && params.Pool == nil {
 		// When USE_GOMA=true or USE_RBE=true are set and the rule is not supported by goma/RBE, restrict
 		// jobs to the local parallelism value
 		params.Pool = localPool
diff --git a/cmd/soong_ui/main.go b/cmd/soong_ui/main.go
index 974c644..db61fba 100644
--- a/cmd/soong_ui/main.go
+++ b/cmd/soong_ui/main.go
@@ -174,6 +174,10 @@
 	stat.AddOutput(status.NewProtoErrorLog(log, filepath.Join(logsDir, c.logsPrefix+"build_error")))
 	stat.AddOutput(status.NewCriticalPath(log))
 
+	buildCtx.Verbosef("Detected %.3v GB total RAM", float32(config.TotalRAM())/(1024*1024*1024))
+	buildCtx.Verbosef("Parallelism (local/remote/highmem): %v/%v/%v",
+		config.Parallel(), config.RemoteParallel(), config.HighmemParallel())
+
 	defer met.Dump(filepath.Join(logsDir, c.logsPrefix+"soong_metrics"))
 
 	if start, ok := os.LookupEnv("TRACE_BEGIN_SOONG"); ok {
diff --git a/java/droiddoc.go b/java/droiddoc.go
index f62f5f9..a10ec81 100644
--- a/java/droiddoc.go
+++ b/java/droiddoc.go
@@ -1456,6 +1456,8 @@
 
 func metalavaCmd(ctx android.ModuleContext, rule *android.RuleBuilder, javaVersion javaVersion, srcs android.Paths,
 	srcJarList android.Path, bootclasspath, classpath classpath, sourcepaths android.Paths) *android.RuleBuilderCommand {
+	// Metalava uses lots of memory, restrict the number of metalava jobs that can run in parallel.
+	rule.HighMem()
 	cmd := rule.Command().BuiltTool(ctx, "metalava").
 		Flag(config.JavacVmFlags).
 		FlagWithArg("-encoding ", "UTF-8").
diff --git a/ui/build/build.go b/ui/build/build.go
index 69ef003..f3feac2 100644
--- a/ui/build/build.go
+++ b/ui/build/build.go
@@ -48,8 +48,11 @@
 
 var combinedBuildNinjaTemplate = template.Must(template.New("combined").Parse(`
 builddir = {{.OutDir}}
-pool local_pool
+{{if .UseRemoteBuild }}pool local_pool
  depth = {{.Parallel}}
+{{end -}}
+pool highmem_pool
+ depth = {{.HighmemParallel}}
 build _kati_always_build_: phony
 {{if .HasKatiSuffix}}subninja {{.KatiBuildNinjaFile}}
 subninja {{.KatiPackageNinjaFile}}
diff --git a/ui/build/config.go b/ui/build/config.go
index c084171..9b19ede 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -722,6 +722,33 @@
 	return c.parallel
 }
 
+func (c *configImpl) HighmemParallel() int {
+	if i, ok := c.environ.GetInt("NINJA_HIGHMEM_NUM_JOBS"); ok {
+		return i
+	}
+
+	const minMemPerHighmemProcess = 8 * 1024 * 1024 * 1024
+	parallel := c.Parallel()
+	if c.UseRemoteBuild() {
+		// Ninja doesn't support nested pools, and when remote builds are enabled the total ninja parallelism
+		// is set very high (i.e. 500).  Using a large value here would cause the total number of running jobs
+		// to be the sum of the sizes of the local and highmem pools, which will cause extra CPU contention.
+		// Return 1/16th of the size of the local pool, rounding up.
+		return (parallel + 15) / 16
+	} else if c.totalRAM == 0 {
+		// Couldn't detect the total RAM, don't restrict highmem processes.
+		return parallel
+	} else if c.totalRAM <= 32*1024*1024*1024 {
+		// Less than 32GB of ram, restrict to 2 highmem processes
+		return 2
+	} else if p := int(c.totalRAM / minMemPerHighmemProcess); p < parallel {
+		// If less than 8GB total RAM per process, reduce the number of highmem processes
+		return p
+	}
+	// No restriction on highmem processes
+	return parallel
+}
+
 func (c *configImpl) TotalRAM() uint64 {
 	return c.totalRAM
 }
@@ -782,10 +809,11 @@
 // gomacc) are run in parallel.  Note the parallelism of all other jobs is
 // still limited by Parallel()
 func (c *configImpl) RemoteParallel() int {
-	if v, ok := c.environ.Get("NINJA_REMOTE_NUM_JOBS"); ok {
-		if i, err := strconv.Atoi(v); err == nil {
-			return i
-		}
+	if !c.UseRemoteBuild() {
+		return 0
+	}
+	if i, ok := c.environ.GetInt("NINJA_REMOTE_NUM_JOBS"); ok {
+		return i
 	}
 	return 500
 }
diff --git a/ui/build/config_darwin.go b/ui/build/config_darwin.go
index 480d8d1..fe74e31 100644
--- a/ui/build/config_darwin.go
+++ b/ui/build/config_darwin.go
@@ -22,7 +22,7 @@
 func detectTotalRAM(ctx Context) uint64 {
 	s, err := syscall.Sysctl("hw.memsize")
 	if err != nil {
-		ctx.Printf("Failed to get system memory size: %s")
+		ctx.Printf("Failed to get system memory size: %v", err)
 		return 0
 	}
 
@@ -32,7 +32,7 @@
 	}
 
 	if len(s) != 8 {
-		ctx.Printf("Failed to get system memory size, returned %d bytes, 8", len(s))
+		ctx.Printf("Failed to get system memory size, returned %d bytes, expecting 8 bytes", len(s))
 		return 0
 	}
 
diff --git a/ui/build/config_linux.go b/ui/build/config_linux.go
index 9e1bdc7..162d372 100644
--- a/ui/build/config_linux.go
+++ b/ui/build/config_linux.go
@@ -20,9 +20,8 @@
 	var info syscall.Sysinfo_t
 	err := syscall.Sysinfo(&info)
 	if err != nil {
-		ctx.Printf("Failed to get system memory size: %s")
+		ctx.Printf("Failed to get system memory size: %v", err)
 		return 0
 	}
-	memBytes := uint64(info.Totalram) * uint64(info.Unit)
-	return memBytes
+	return uint64(info.Totalram) * uint64(info.Unit)
 }
diff --git a/ui/build/environment.go b/ui/build/environment.go
index d8ff7f2..9bca7c0 100644
--- a/ui/build/environment.go
+++ b/ui/build/environment.go
@@ -19,6 +19,7 @@
 	"fmt"
 	"io"
 	"os"
+	"strconv"
 	"strings"
 )
 
@@ -44,6 +45,17 @@
 	return "", false
 }
 
+// Get returns the int value associated with the key, and whether it exists
+// and is a valid int.
+func (e *Environment) GetInt(key string) (int, bool) {
+	if v, ok := e.Get(key); ok {
+		if i, err := strconv.Atoi(v); err == nil {
+			return i, true
+		}
+	}
+	return 0, false
+}
+
 // Set sets the value associated with the key, overwriting the current value
 // if it exists.
 func (e *Environment) Set(key, value string) {