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-rw-r--r--libgo/runtime/cpuprof.goc442
-rw-r--r--libgo/runtime/go-signal.c2
-rw-r--r--libgo/runtime/malloc.h3
-rw-r--r--libgo/runtime/proc.c58
-rw-r--r--libgo/runtime/runtime.h5
-rw-r--r--libgo/runtime/runtime1.goc4
6 files changed, 40 insertions, 474 deletions
diff --git a/libgo/runtime/cpuprof.goc b/libgo/runtime/cpuprof.goc
deleted file mode 100644
index 123e074..0000000
--- a/libgo/runtime/cpuprof.goc
+++ /dev/null
@@ -1,442 +0,0 @@
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// CPU profiling.
-// Based on algorithms and data structures used in
-// http://code.google.com/p/google-perftools/.
-//
-// The main difference between this code and the google-perftools
-// code is that this code is written to allow copying the profile data
-// to an arbitrary io.Writer, while the google-perftools code always
-// writes to an operating system file.
-//
-// The signal handler for the profiling clock tick adds a new stack trace
-// to a hash table tracking counts for recent traces. Most clock ticks
-// hit in the cache. In the event of a cache miss, an entry must be
-// evicted from the hash table, copied to a log that will eventually be
-// written as profile data. The google-perftools code flushed the
-// log itself during the signal handler. This code cannot do that, because
-// the io.Writer might block or need system calls or locks that are not
-// safe to use from within the signal handler. Instead, we split the log
-// into two halves and let the signal handler fill one half while a goroutine
-// is writing out the other half. When the signal handler fills its half, it
-// offers to swap with the goroutine. If the writer is not done with its half,
-// we lose the stack trace for this clock tick (and record that loss).
-// The goroutine interacts with the signal handler by calling getprofile() to
-// get the next log piece to write, implicitly handing back the last log
-// piece it obtained.
-//
-// The state of this dance between the signal handler and the goroutine
-// is encoded in the Profile.handoff field. If handoff == 0, then the goroutine
-// is not using either log half and is waiting (or will soon be waiting) for
-// a new piece by calling notesleep(&p->wait). If the signal handler
-// changes handoff from 0 to non-zero, it must call notewakeup(&p->wait)
-// to wake the goroutine. The value indicates the number of entries in the
-// log half being handed off. The goroutine leaves the non-zero value in
-// place until it has finished processing the log half and then flips the number
-// back to zero. Setting the high bit in handoff means that the profiling is over,
-// and the goroutine is now in charge of flushing the data left in the hash table
-// to the log and returning that data.
-//
-// The handoff field is manipulated using atomic operations.
-// For the most part, the manipulation of handoff is orderly: if handoff == 0
-// then the signal handler owns it and can change it to non-zero.
-// If handoff != 0 then the goroutine owns it and can change it to zero.
-// If that were the end of the story then we would not need to manipulate
-// handoff using atomic operations. The operations are needed, however,
-// in order to let the log closer set the high bit to indicate "EOF" safely
-// in the situation when normally the goroutine "owns" handoff.
-
-package runtime
-#include "runtime.h"
-#include "arch.h"
-#include "malloc.h"
-
-#include "array.h"
-typedef struct __go_open_array Slice;
-#define array __values
-#define len __count
-#define cap __capacity
-
-enum
-{
- HashSize = 1<<10,
- LogSize = 1<<17,
- Assoc = 4,
- MaxStack = 64,
-};
-
-typedef struct Profile Profile;
-typedef struct Bucket Bucket;
-typedef struct Entry Entry;
-
-struct Entry {
- uintptr count;
- uintptr depth;
- uintptr stack[MaxStack];
-};
-
-struct Bucket {
- Entry entry[Assoc];
-};
-
-struct Profile {
- bool on; // profiling is on
- Note wait; // goroutine waits here
- uintptr count; // tick count
- uintptr evicts; // eviction count
- uintptr lost; // lost ticks that need to be logged
-
- // Active recent stack traces.
- Bucket hash[HashSize];
-
- // Log of traces evicted from hash.
- // Signal handler has filled log[toggle][:nlog].
- // Goroutine is writing log[1-toggle][:handoff].
- uintptr log[2][LogSize/2];
- uintptr nlog;
- int32 toggle;
- uint32 handoff;
-
- // Writer state.
- // Writer maintains its own toggle to avoid races
- // looking at signal handler's toggle.
- uint32 wtoggle;
- bool wholding; // holding & need to release a log half
- bool flushing; // flushing hash table - profile is over
- bool eod_sent; // special end-of-data record sent; => flushing
-};
-
-static Lock lk;
-static Profile *prof;
-
-static void tick(uintptr*, int32);
-static void add(Profile*, uintptr*, int32);
-static bool evict(Profile*, Entry*);
-static bool flushlog(Profile*);
-
-static uintptr eod[3] = {0, 1, 0};
-
-// LostProfileData is a no-op function used in profiles
-// to mark the number of profiling stack traces that were
-// discarded due to slow data writers.
-static void
-LostProfileData(void)
-{
-}
-
-extern void runtime_SetCPUProfileRate(intgo)
- __asm__ (GOSYM_PREFIX "runtime.SetCPUProfileRate");
-
-// SetCPUProfileRate sets the CPU profiling rate.
-// The user documentation is in debug.go.
-void
-runtime_SetCPUProfileRate(intgo hz)
-{
- uintptr *p;
- uintptr n;
-
- // Clamp hz to something reasonable.
- if(hz < 0)
- hz = 0;
- if(hz > 1000000)
- hz = 1000000;
-
- runtime_lock(&lk);
- if(hz > 0) {
- if(prof == nil) {
- prof = runtime_SysAlloc(sizeof *prof, &mstats()->other_sys);
- if(prof == nil) {
- runtime_printf("runtime: cpu profiling cannot allocate memory\n");
- runtime_unlock(&lk);
- return;
- }
- }
- if(prof->on || prof->handoff != 0) {
- runtime_printf("runtime: cannot set cpu profile rate until previous profile has finished.\n");
- runtime_unlock(&lk);
- return;
- }
-
- prof->on = true;
- p = prof->log[0];
- // pprof binary header format.
- // http://code.google.com/p/google-perftools/source/browse/trunk/src/profiledata.cc#117
- *p++ = 0; // count for header
- *p++ = 3; // depth for header
- *p++ = 0; // version number
- *p++ = 1000000 / hz; // period (microseconds)
- *p++ = 0;
- prof->nlog = p - prof->log[0];
- prof->toggle = 0;
- prof->wholding = false;
- prof->wtoggle = 0;
- prof->flushing = false;
- prof->eod_sent = false;
- runtime_noteclear(&prof->wait);
-
- runtime_setcpuprofilerate(tick, hz);
- } else if(prof != nil && prof->on) {
- runtime_setcpuprofilerate(nil, 0);
- prof->on = false;
-
- // Now add is not running anymore, and getprofile owns the entire log.
- // Set the high bit in prof->handoff to tell getprofile.
- for(;;) {
- n = prof->handoff;
- if(n&0x80000000)
- runtime_printf("runtime: setcpuprofile(off) twice");
- if(runtime_cas(&prof->handoff, n, n|0x80000000))
- break;
- }
- if(n == 0) {
- // we did the transition from 0 -> nonzero so we wake getprofile
- runtime_notewakeup(&prof->wait);
- }
- }
- runtime_unlock(&lk);
-}
-
-static void
-tick(uintptr *pc, int32 n)
-{
- add(prof, pc, n);
-}
-
-// add adds the stack trace to the profile.
-// It is called from signal handlers and other limited environments
-// and cannot allocate memory or acquire locks that might be
-// held at the time of the signal, nor can it use substantial amounts
-// of stack. It is allowed to call evict.
-static void
-add(Profile *p, uintptr *pc, int32 n)
-{
- int32 i, j;
- uintptr h, x;
- Bucket *b;
- Entry *e;
-
- if(n > MaxStack)
- n = MaxStack;
-
- // Compute hash.
- h = 0;
- for(i=0; i<n; i++) {
- h = h<<8 | (h>>(8*(sizeof(h)-1)));
- x = pc[i];
- h += x*31 + x*7 + x*3;
- }
- p->count++;
-
- // Add to entry count if already present in table.
- b = &p->hash[h%HashSize];
- for(i=0; i<Assoc; i++) {
- e = &b->entry[i];
- if(e->depth != (uintptr)n)
- continue;
- for(j=0; j<n; j++)
- if(e->stack[j] != pc[j])
- goto ContinueAssoc;
- e->count++;
- return;
- ContinueAssoc:;
- }
-
- // Evict entry with smallest count.
- e = &b->entry[0];
- for(i=1; i<Assoc; i++)
- if(b->entry[i].count < e->count)
- e = &b->entry[i];
- if(e->count > 0) {
- if(!evict(p, e)) {
- // Could not evict entry. Record lost stack.
- p->lost++;
- return;
- }
- p->evicts++;
- }
-
- // Reuse the newly evicted entry.
- e->depth = n;
- e->count = 1;
- for(i=0; i<n; i++)
- e->stack[i] = pc[i];
-}
-
-// evict copies the given entry's data into the log, so that
-// the entry can be reused. evict is called from add, which
-// is called from the profiling signal handler, so it must not
-// allocate memory or block. It is safe to call flushLog.
-// evict returns true if the entry was copied to the log,
-// false if there was no room available.
-static bool
-evict(Profile *p, Entry *e)
-{
- int32 i, d, nslot;
- uintptr *log, *q;
-
- d = e->depth;
- nslot = d+2;
- log = p->log[p->toggle];
- if(p->nlog+nslot > nelem(p->log[0])) {
- if(!flushlog(p))
- return false;
- log = p->log[p->toggle];
- }
-
- q = log+p->nlog;
- *q++ = e->count;
- *q++ = d;
- for(i=0; i<d; i++)
- *q++ = e->stack[i];
- p->nlog = q - log;
- e->count = 0;
- return true;
-}
-
-// flushlog tries to flush the current log and switch to the other one.
-// flushlog is called from evict, called from add, called from the signal handler,
-// so it cannot allocate memory or block. It can try to swap logs with
-// the writing goroutine, as explained in the comment at the top of this file.
-static bool
-flushlog(Profile *p)
-{
- uintptr *log, *q;
-
- if(!runtime_cas(&p->handoff, 0, p->nlog))
- return false;
- runtime_notewakeup(&p->wait);
-
- p->toggle = 1 - p->toggle;
- log = p->log[p->toggle];
- q = log;
- if(p->lost > 0) {
- *q++ = p->lost;
- *q++ = 1;
- *q++ = (uintptr)LostProfileData;
- p->lost = 0;
- }
- p->nlog = q - log;
- return true;
-}
-
-// getprofile blocks until the next block of profiling data is available
-// and returns it as a []byte. It is called from the writing goroutine.
-Slice
-getprofile(Profile *p)
-{
- uint32 i, j, n;
- Slice ret;
- Bucket *b;
- Entry *e;
-
- ret.array = nil;
- ret.len = 0;
- ret.cap = 0;
-
- if(p == nil)
- return ret;
-
- if(p->wholding) {
- // Release previous log to signal handling side.
- // Loop because we are racing against SetCPUProfileRate(0).
- for(;;) {
- n = p->handoff;
- if(n == 0) {
- runtime_printf("runtime: phase error during cpu profile handoff\n");
- return ret;
- }
- if(n & 0x80000000) {
- p->wtoggle = 1 - p->wtoggle;
- p->wholding = false;
- p->flushing = true;
- goto flush;
- }
- if(runtime_cas(&p->handoff, n, 0))
- break;
- }
- p->wtoggle = 1 - p->wtoggle;
- p->wholding = false;
- }
-
- if(p->flushing)
- goto flush;
-
- if(!p->on && p->handoff == 0)
- return ret;
-
- // Wait for new log.
- runtime_notetsleepg(&p->wait, -1);
- runtime_noteclear(&p->wait);
-
- n = p->handoff;
- if(n == 0) {
- runtime_printf("runtime: phase error during cpu profile wait\n");
- return ret;
- }
- if(n == 0x80000000) {
- p->flushing = true;
- goto flush;
- }
- n &= ~0x80000000;
-
- // Return new log to caller.
- p->wholding = true;
-
- ret.array = (byte*)p->log[p->wtoggle];
- ret.len = n*sizeof(uintptr);
- ret.cap = ret.len;
- return ret;
-
-flush:
- // In flush mode.
- // Add is no longer being called. We own the log.
- // Also, p->handoff is non-zero, so flushlog will return false.
- // Evict the hash table into the log and return it.
- for(i=0; i<HashSize; i++) {
- b = &p->hash[i];
- for(j=0; j<Assoc; j++) {
- e = &b->entry[j];
- if(e->count > 0 && !evict(p, e)) {
- // Filled the log. Stop the loop and return what we've got.
- goto breakflush;
- }
- }
- }
-breakflush:
-
- // Return pending log data.
- if(p->nlog > 0) {
- // Note that we're using toggle now, not wtoggle,
- // because we're working on the log directly.
- ret.array = (byte*)p->log[p->toggle];
- ret.len = p->nlog*sizeof(uintptr);
- ret.cap = ret.len;
- p->nlog = 0;
- return ret;
- }
-
- // Made it through the table without finding anything to log.
- if(!p->eod_sent) {
- // We may not have space to append this to the partial log buf,
- // so we always return a new slice for the end-of-data marker.
- p->eod_sent = true;
- ret.array = (byte*)eod;
- ret.len = sizeof eod;
- ret.cap = ret.len;
- return ret;
- }
-
- // Finally done. Clean up and return nil.
- p->flushing = false;
- if(!runtime_cas(&p->handoff, p->handoff, 0))
- runtime_printf("runtime: profile flush racing with something\n");
- return ret; // set to nil at top of function
-}
-
-// CPUProfile returns the next cpu profile block as a []byte.
-// The user documentation is in debug.go.
-func CPUProfile() (ret Slice) {
- ret = getprofile(prof);
-}
diff --git a/libgo/runtime/go-signal.c b/libgo/runtime/go-signal.c
index 0aef2fc..99829eb 100644
--- a/libgo/runtime/go-signal.c
+++ b/libgo/runtime/go-signal.c
@@ -156,6 +156,8 @@ runtime_sighandler (int sig, Siginfo *info,
#ifdef SIGPROF
if (sig == SIGPROF)
{
+ /* FIXME: Handle m == NULL by calling something like gc's
+ sigprofNonGo. */
if (m != NULL && gp != m->g0 && gp != m->gsignal)
runtime_sigprof ();
return;
diff --git a/libgo/runtime/malloc.h b/libgo/runtime/malloc.h
index 5e74b8c..12a25b57 100644
--- a/libgo/runtime/malloc.h
+++ b/libgo/runtime/malloc.h
@@ -184,7 +184,8 @@ enum
// SysFault marks a (already SysAlloc'd) region to fault
// if accessed. Used only for debugging the runtime.
-void* runtime_SysAlloc(uintptr nbytes, uint64 *stat);
+void* runtime_SysAlloc(uintptr nbytes, uint64 *stat)
+ __asm__ (GOSYM_PREFIX "runtime.sysAlloc");
void runtime_SysFree(void *v, uintptr nbytes, uint64 *stat);
void runtime_SysUnused(void *v, uintptr nbytes);
void runtime_SysUsed(void *v, uintptr nbytes);
diff --git a/libgo/runtime/proc.c b/libgo/runtime/proc.c
index d8a26fd..246ab7d 100644
--- a/libgo/runtime/proc.c
+++ b/libgo/runtime/proc.c
@@ -2686,11 +2686,8 @@ runtime_mcount(void)
}
static struct {
- Lock;
- void (*fn)(uintptr*, int32);
+ uint32 lock;
int32 hz;
- uintptr pcbuf[TracebackMaxFrames];
- Location locbuf[TracebackMaxFrames];
} prof;
static void System(void) {}
@@ -2703,8 +2700,11 @@ runtime_sigprof()
M *mp = g->m;
int32 n, i;
bool traceback;
+ uintptr pcbuf[TracebackMaxFrames];
+ Location locbuf[TracebackMaxFrames];
+ Slice stk;
- if(prof.fn == nil || prof.hz == 0)
+ if(prof.hz == 0)
return;
if(mp == nil)
@@ -2718,12 +2718,6 @@ runtime_sigprof()
if(mp->mcache == nil)
traceback = false;
- runtime_lock(&prof);
- if(prof.fn == nil) {
- runtime_unlock(&prof);
- mp->mallocing--;
- return;
- }
n = 0;
if(runtime_atomicload(&runtime_in_callers) > 0) {
@@ -2735,34 +2729,44 @@ runtime_sigprof()
}
if(traceback) {
- n = runtime_callers(0, prof.locbuf, nelem(prof.locbuf), false);
+ n = runtime_callers(0, locbuf, nelem(locbuf), false);
for(i = 0; i < n; i++)
- prof.pcbuf[i] = prof.locbuf[i].pc;
+ pcbuf[i] = locbuf[i].pc;
}
if(!traceback || n <= 0) {
n = 2;
- prof.pcbuf[0] = (uintptr)runtime_getcallerpc(&n);
+ pcbuf[0] = (uintptr)runtime_getcallerpc(&n);
if(mp->gcing || mp->helpgc)
- prof.pcbuf[1] = (uintptr)GC;
+ pcbuf[1] = (uintptr)GC;
else
- prof.pcbuf[1] = (uintptr)System;
+ pcbuf[1] = (uintptr)System;
+ }
+
+ if (prof.hz != 0) {
+ stk.__values = &pcbuf[0];
+ stk.__count = n;
+ stk.__capacity = n;
+
+ // Simple cas-lock to coordinate with setcpuprofilerate.
+ while (!runtime_cas(&prof.lock, 0, 1)) {
+ runtime_osyield();
+ }
+ if (prof.hz != 0) {
+ runtime_cpuprofAdd(stk);
+ }
+ runtime_atomicstore(&prof.lock, 0);
}
- prof.fn(prof.pcbuf, n);
- runtime_unlock(&prof);
+
mp->mallocing--;
}
// Arrange to call fn with a traceback hz times a second.
void
-runtime_setcpuprofilerate(void (*fn)(uintptr*, int32), int32 hz)
+runtime_setcpuprofilerate_m(int32 hz)
{
// Force sane arguments.
if(hz < 0)
hz = 0;
- if(hz == 0)
- fn = nil;
- if(fn == nil)
- hz = 0;
// Disable preemption, otherwise we can be rescheduled to another thread
// that has profiling enabled.
@@ -2773,10 +2777,12 @@ runtime_setcpuprofilerate(void (*fn)(uintptr*, int32), int32 hz)
// it would deadlock.
runtime_resetcpuprofiler(0);
- runtime_lock(&prof);
- prof.fn = fn;
+ while (!runtime_cas(&prof.lock, 0, 1)) {
+ runtime_osyield();
+ }
prof.hz = hz;
- runtime_unlock(&prof);
+ runtime_atomicstore(&prof.lock, 0);
+
runtime_lock(&runtime_sched);
runtime_sched.profilehz = hz;
runtime_unlock(&runtime_sched);
diff --git a/libgo/runtime/runtime.h b/libgo/runtime/runtime.h
index b7e5902..96f550c 100644
--- a/libgo/runtime/runtime.h
+++ b/libgo/runtime/runtime.h
@@ -417,7 +417,10 @@ void runtime_freezetheworld(void);
void runtime_unwindstack(G*, byte*);
void runtime_sigprof();
void runtime_resetcpuprofiler(int32);
-void runtime_setcpuprofilerate(void(*)(uintptr*, int32), int32);
+void runtime_setcpuprofilerate_m(int32)
+ __asm__ (GOSYM_PREFIX "runtime.setcpuprofilerate_m");
+void runtime_cpuprofAdd(Slice)
+ __asm__ (GOSYM_PREFIX "runtime.cpuprofAdd");
void runtime_usleep(uint32)
__asm__ (GOSYM_PREFIX "runtime.usleep");
int64 runtime_cputicks(void)
diff --git a/libgo/runtime/runtime1.goc b/libgo/runtime/runtime1.goc
index 2238980..bc5ba4a 100644
--- a/libgo/runtime/runtime1.goc
+++ b/libgo/runtime/runtime1.goc
@@ -55,10 +55,6 @@ func getgoroot() (out String) {
out = runtime_getenv("GOROOT");
}
-func runtime_pprof.runtime_cyclesPerSecond() (res int64) {
- res = runtime_tickspersecond();
-}
-
func sync.runtime_procPin() (p int) {
M *mp;
generated by cgit v1.1 at 2024-10-31 14:08:25 +0000