runtime: more malloc statistics

expvar: default publishings for cmdline, memstats
godoc: import expvar

R=r
CC=golang-dev
http://codereview.appspot.com/815041

7 files changed, 143 insertions, 32 deletions

diff --git a/src/pkg/expvar/expvar.go b/src/pkg/expvar/expvar.go
index b8f9bae5d..bed31db5d 100644
--- a/src/pkg/expvar/expvar.go
+++ b/src/pkg/expvar/expvar.go
@@ -5,13 +5,28 @@
 // The expvar package provides a standardized interface to public variables,
 // such as operation counters in servers. It exposes these variables via
 // HTTP at /debug/vars in JSON format.
+//
+// In addition to adding the HTTP handler, this package registers the
+// following variables:
+//
+//	cmdline   os.Args
+//	memstats  runtime.Memstats
+//
+// The package is sometimes only imported for the side effect of
+// registering its HTTP handler and the above variables.  To use it
+// this way, simply link this package into your program:
+//	import _ "expvar"
+//
 package expvar
 
 import (
 	"bytes"
 	"fmt"
 	"http"
+	"json"
 	"log"
+	"os"
+	"runtime"
 	"strconv"
 	"sync"
 )
@@ -128,6 +143,12 @@ type IntFunc func() int64
 
 func (v IntFunc) String() string { return strconv.Itoa64(v()) }
 
+// StringFunc wraps a func() string to create value that satisfies the Var interface.
+// The function will be called each time the Var is evaluated.
+type StringFunc func() string
+
+func (f StringFunc) String() string { return f() }
+
 
 // All published variables.
 var vars map[string]Var = make(map[string]Var)
@@ -204,9 +225,26 @@ func expvarHandler(c *http.Conn, req *http.Request) {
 			fmt.Fprintf(c, ",\n")
 		}
 		first = false
-		fmt.Fprintf(c, "  %q: %s", name, value)
+		fmt.Fprintf(c, "%q: %s", name, value)
 	}
 	fmt.Fprintf(c, "\n}\n")
 }
 
-func init() { http.Handle("/debug/vars", http.HandlerFunc(expvarHandler)) }
+func memstats() string {
+	var buf bytes.Buffer
+	json.MarshalIndent(&buf, &runtime.MemStats, "    ")
+	s := buf.String()
+	return s[0 : len(s)-1] // chop final \n
+}
+
+func cmdline() string {
+	var buf bytes.Buffer
+	json.Marshal(&buf, os.Args)
+	return buf.String()
+}
+
+func init() {
+	http.Handle("/debug/vars", http.HandlerFunc(expvarHandler))
+	Publish("cmdline", StringFunc(cmdline))
+	Publish("memstats", StringFunc(memstats))
+}
diff --git a/src/pkg/runtime/extern.go b/src/pkg/runtime/extern.go
index 17ef63440..bcef7244a 100644
--- a/src/pkg/runtime/extern.go
+++ b/src/pkg/runtime/extern.go
@@ -134,20 +134,40 @@ func Signame(sig int32) string
 func Siginit()
 
 type MemStatsType struct {
-	Alloc      uint64
-	TotalAlloc uint64
-	Sys        uint64
-	Stacks     uint64
-	InusePages uint64
-	NextGC     uint64
-	HeapAlloc  uint64
-	Lookups    uint64
-	Mallocs    uint64
-	PauseNs    uint64
-	NumGC      uint32
-	EnableGC   bool
-	DebugGC    bool
-	BySize     [67]struct {
+	// General statistics.
+	// Not locked during update; approximate.
+	Alloc      uint64 // bytes allocated and still in use
+	TotalAlloc uint64 // bytes allocated (even if freed)
+	Sys        uint64 // bytes obtained from system (should be sum of XxxSys below)
+	Lookups    uint64 // number of pointer lookups
+	Mallocs    uint64 // number of mallocs
+
+	// Main allocation heap statistics.
+	HeapAlloc uint64 // bytes allocated and still in use
+	HeapSys   uint64 // bytes obtained from system
+	HeapIdle  uint64 // bytes in idle spans
+	HeapInuse uint64 // bytes in non-idle span
+
+	// Low-level fixed-size structure allocator statistics.
+	//	Inuse is bytes used now.
+	//	Sys is bytes obtained from system.
+	StackInuse  uint64 // bootstrap stacks
+	StackSys    uint64
+	MSpanInuse  uint64 // mspan structures
+	MSpanSys    uint64
+	MCacheInuse uint64 // mcache structures
+	MCacheSys   uint64
+
+	// Garbage collector statistics.
+	NextGC   uint64
+	PauseNs  uint64
+	NumGC    uint32
+	EnableGC bool
+	DebugGC  bool
+
+	// Per-size allocation statistics.
+	// Not locked during update; approximate.
+	BySize [67]struct {
 		Size    uint32
 		Mallocs uint64
 		Frees   uint64
diff --git a/src/pkg/runtime/malloc.cgo b/src/pkg/runtime/malloc.cgo
index fed8e037c..2e7818a39 100644
--- a/src/pkg/runtime/malloc.cgo
+++ b/src/pkg/runtime/malloc.cgo
@@ -234,7 +234,12 @@ mlookup(void *v, byte **base, uintptr *size, MSpan **sp, uint32 **ref)
 MCache*
 allocmcache(void)
 {
-	return FixAlloc_Alloc(&mheap.cachealloc);
+	MCache *c;
+
+	c = FixAlloc_Alloc(&mheap.cachealloc);
+	mstats.mcache_inuse = mheap.cachealloc.inuse;
+	mstats.mcache_sys = mheap.cachealloc.sys;
+	return c;
 }
 
 void
@@ -289,6 +294,8 @@ stackalloc(uint32 n)
 			throw("stackalloc");
 		}
 		v = FixAlloc_Alloc(&stacks);
+		mstats.stacks_inuse = stacks.inuse;
+		mstats.stacks_sys = stacks.sys;
 		unlock(&stacks);
 		return v;
 	}
@@ -305,6 +312,8 @@ stackfree(void *v)
 	if(m->mallocing || m->gcing) {
 		lock(&stacks);
 		FixAlloc_Free(&stacks, v);
+		mstats.stacks_inuse = stacks.inuse;
+		mstats.stacks_sys = stacks.sys;
 		unlock(&stacks);
 		return;
 	}
diff --git a/src/pkg/runtime/malloc.h b/src/pkg/runtime/malloc.h
index 621394bda..ff869cacb 100644
--- a/src/pkg/runtime/malloc.h
+++ b/src/pkg/runtime/malloc.h
@@ -157,6 +157,8 @@ struct FixAlloc
 	MLink *list;
 	byte *chunk;
 	uint32 nchunk;
+	uintptr inuse;	// in-use bytes now
+	uintptr sys;	// bytes obtained from system
 };
 
 void	FixAlloc_Init(FixAlloc *f, uintptr size, void *(*alloc)(uintptr), void (*first)(void*, byte*), void *arg);
@@ -168,19 +170,39 @@ void	FixAlloc_Free(FixAlloc *f, void *p);
 // Shared with Go: if you edit this structure, also edit extern.go.
 struct MStats
 {
-	uint64	alloc;	// unprotected (approximate)
-	uint64	total_alloc;	// unprotected (approximate)
-	uint64	sys;
-	uint64	stacks;
-	uint64	inuse_pages;	// protected by mheap.Lock
-	uint64	next_gc;	// protected by mheap.Lock
-	uint64	heap_alloc;	// protected by mheap.Lock
-	uint64	nlookup;	// unprotected (approximate)
-	uint64	nmalloc;	// unprotected (approximate)
+	// General statistics.  No locking; approximate.
+	uint64	alloc;		// bytes allocated and still in use
+	uint64	total_alloc;	// bytes allocated (even if freed)
+	uint64	sys;		// bytes obtained from system (should be sum of xxx_sys below)
+	uint64	nlookup;	// number of pointer lookups
+	uint64	nmalloc;	// number of mallocs
+	
+	// Statistics about malloc heap.
+	// protected by mheap.Lock
+	uint64	heap_alloc;	// bytes allocated and still in use
+	uint64	heap_sys;	// bytes obtained from system
+	uint64	heap_idle;	// bytes in idle spans
+	uint64	heap_inuse;	// bytes in non-idle spans
+
+	// Statistics about allocation of low-level fixed-size structures.
+	// Protected by FixAlloc locks.
+	uint64	stacks_inuse;	// bootstrap stacks
+	uint64	stacks_sys;
+	uint64	mspan_inuse;	// MSpan structures
+	uint64	mspan_sys;
+	uint64	mcache_inuse;	// MCache structures
+	uint64	mcache_sys;
+	
+	// Statistics about garbage collector.
+	// Protected by stopping the world during GC.
+	uint64	next_gc;	// next GC (in heap_alloc time)
 	uint64	pause_ns;
 	uint32	numgc;
 	bool	enablegc;
 	bool	debuggc;
+	
+	// Statistics about allocation size classes.
+	// No locking; approximate.
 	struct {
 		uint32 size;
 		uint64 nmalloc;
diff --git a/src/pkg/runtime/mfixalloc.c b/src/pkg/runtime/mfixalloc.c
index dd4f3f251..8347a1539 100644
--- a/src/pkg/runtime/mfixalloc.c
+++ b/src/pkg/runtime/mfixalloc.c
@@ -21,6 +21,8 @@ FixAlloc_Init(FixAlloc *f, uintptr size, void *(*alloc)(uintptr), void (*first)(
 	f->list = nil;
 	f->chunk = nil;
 	f->nchunk = 0;
+	f->inuse = 0;
+	f->sys = 0;
 }
 
 void*
@@ -31,9 +33,11 @@ FixAlloc_Alloc(FixAlloc *f)
 	if(f->list) {
 		v = f->list;
 		f->list = *(void**)f->list;
+		f->inuse += f->size;
 		return v;
 	}
 	if(f->nchunk < f->size) {
+		f->sys += FixAllocChunk;
 		f->chunk = f->alloc(FixAllocChunk);
 		if(f->chunk == nil)
 			throw("out of memory (FixAlloc)");
@@ -44,12 +48,14 @@ FixAlloc_Alloc(FixAlloc *f)
 		f->first(f->arg, v);
 	f->chunk += f->size;
 	f->nchunk -= f->size;
+	f->inuse += f->size;
 	return v;
 }
 
 void
 FixAlloc_Free(FixAlloc *f, void *p)
 {
+	f->inuse -= f->size;
 	*(void**)p = f->list;
 	f->list = p;
 }
diff --git a/src/pkg/runtime/mheap.c b/src/pkg/runtime/mheap.c
index 5f9406b69..1b47b3fe2 100644
--- a/src/pkg/runtime/mheap.c
+++ b/src/pkg/runtime/mheap.c
@@ -62,7 +62,7 @@ MHeap_Alloc(MHeap *h, uintptr npage, int32 sizeclass, int32 acct)
 	m->mcache->local_alloc = 0;
 	s = MHeap_AllocLocked(h, npage, sizeclass);
 	if(s != nil) {
-		mstats.inuse_pages += npage;
+		mstats.heap_inuse += npage<<PageShift;
 		if(acct)
 			mstats.heap_alloc += npage<<PageShift;
 	}
@@ -104,6 +104,8 @@ HaveSpan:
 	if(s->npages > npage) {
 		// Trim extra and put it back in the heap.
 		t = FixAlloc_Alloc(&h->spanalloc);
+		mstats.mspan_inuse = h->spanalloc.inuse;
+		mstats.mspan_sys = h->spanalloc.sys;
 		MSpan_Init(t, s->start + npage, s->npages - npage);
 		s->npages = npage;
 		MHeapMap_Set(&h->map, t->start - 1, s);
@@ -191,6 +193,8 @@ MHeap_Grow(MHeap *h, uintptr npage)
 	// Create a fake "in use" span and free it, so that the
 	// right coalescing happens.
 	s = FixAlloc_Alloc(&h->spanalloc);
+	mstats.mspan_inuse = h->spanalloc.inuse;
+	mstats.mspan_sys = h->spanalloc.sys;
 	MSpan_Init(s, (uintptr)v>>PageShift, ask>>PageShift);
 	MHeapMap_Set(&h->map, s->start, s);
 	MHeapMap_Set(&h->map, s->start + s->npages - 1, s);
@@ -235,7 +239,7 @@ MHeap_Free(MHeap *h, MSpan *s, int32 acct)
 	lock(h);
 	mstats.heap_alloc += m->mcache->local_alloc;
 	m->mcache->local_alloc = 0;
-	mstats.inuse_pages -= s->npages;
+	mstats.heap_inuse -= s->npages<<PageShift;
 	if(acct)
 		mstats.heap_alloc -= s->npages<<PageShift;
 	MHeap_FreeLocked(h, s);
@@ -262,6 +266,8 @@ MHeap_FreeLocked(MHeap *h, MSpan *s)
 		MSpanList_Remove(t);
 		t->state = MSpanDead;
 		FixAlloc_Free(&h->spanalloc, t);
+		mstats.mspan_inuse = h->spanalloc.inuse;
+		mstats.mspan_sys = h->spanalloc.sys;
 	}
 	if((t = MHeapMap_Get(&h->map, s->start + s->npages)) != nil && t->state != MSpanInUse) {
 		s->npages += t->npages;
@@ -269,6 +275,8 @@ MHeap_FreeLocked(MHeap *h, MSpan *s)
 		MSpanList_Remove(t);
 		t->state = MSpanDead;
 		FixAlloc_Free(&h->spanalloc, t);
+		mstats.mspan_inuse = h->spanalloc.inuse;
+		mstats.mspan_sys = h->spanalloc.sys;
 	}
 
 	// Insert s into appropriate list.
diff --git a/src/pkg/runtime/pprof/pprof.go b/src/pkg/runtime/pprof/pprof.go
index 71bca1e07..3a6055128 100644
--- a/src/pkg/runtime/pprof/pprof.go
+++ b/src/pkg/runtime/pprof/pprof.go
@@ -77,16 +77,24 @@ func WriteHeapProfile(w io.Writer) os.Error {
 	fmt.Fprintf(b, "# Alloc = %d\n", s.Alloc)
 	fmt.Fprintf(b, "# TotalAlloc = %d\n", s.TotalAlloc)
 	fmt.Fprintf(b, "# Sys = %d\n", s.Sys)
-	fmt.Fprintf(b, "# Stacks = %d\n", s.Stacks)
-	fmt.Fprintf(b, "# InusePages = %d\n", s.InusePages)
-	fmt.Fprintf(b, "# NextGC = %d\n", s.NextGC)
-	fmt.Fprintf(b, "# HeapAlloc = %d\n", s.HeapAlloc)
 	fmt.Fprintf(b, "# Lookups = %d\n", s.Lookups)
 	fmt.Fprintf(b, "# Mallocs = %d\n", s.Mallocs)
+
+	fmt.Fprintf(b, "# HeapAlloc = %d\n", s.HeapAlloc)
+	fmt.Fprintf(b, "# HeapSys = %d\n", s.HeapSys)
+	fmt.Fprintf(b, "# HeapIdle = %d\n", s.HeapIdle)
+	fmt.Fprintf(b, "# HeapInuse = %d\n", s.HeapInuse)
+
+	fmt.Fprintf(b, "# Stack = %d / %d\n", s.StackInuse, s.StackSys)
+	fmt.Fprintf(b, "# MSpan = %d / %d\n", s.MSpanInuse, s.MSpanSys)
+	fmt.Fprintf(b, "# MCache = %d / %d\n", s.MCacheInuse, s.MCacheSys)
+
+	fmt.Fprintf(b, "# NextGC = %d\n", s.NextGC)
 	fmt.Fprintf(b, "# PauseNs = %d\n", s.PauseNs)
 	fmt.Fprintf(b, "# NumGC = %d\n", s.NumGC)
 	fmt.Fprintf(b, "# EnableGC = %v\n", s.EnableGC)
 	fmt.Fprintf(b, "# DebugGC = %v\n", s.DebugGC)
+
 	fmt.Fprintf(b, "# BySize = Size * (Active = Mallocs - Frees)\n")
 	for _, t := range s.BySize {
 		if t.Mallocs > 0 {