diff options
Diffstat (limited to 'src/runtime/tracecpu.go')
| -rw-r--r-- | src/runtime/tracecpu.go | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/src/runtime/tracecpu.go b/src/runtime/tracecpu.go index e64ca32cdf..c9c3a1511f 100644 --- a/src/runtime/tracecpu.go +++ b/src/runtime/tracecpu.go @@ -224,20 +224,20 @@ func traceCPUSample(gp *g, mp *m, pp *p, stk []uintptr) { // We're going to conditionally write to one of two buffers based on the // generation. To make sure we write to the correct one, we need to make - // sure this thread's trace seqlock is held. If it already is, then we're + // sure this thread's trace write flag is set. If it already is, then we're // in the tracer and we can just take advantage of that. If it isn't, then // we need to acquire it and read the generation. locked := false - if mp.trace.seqlock.Load()%2 == 0 { - mp.trace.seqlock.Add(1) + if !mp.trace.writing.Load() { + mp.trace.writing.Store(true) locked = true } gen := trace.gen.Load() if gen == 0 { - // Tracing is disabled, as it turns out. Release the seqlock if necessary + // Tracing is disabled, as it turns out. Clear the write flag if necessary // and exit. if locked { - mp.trace.seqlock.Add(1) + mp.trace.writing.Store(false) } return } @@ -275,8 +275,8 @@ func traceCPUSample(gp *g, mp *m, pp *p, stk []uintptr) { trace.signalLock.Store(0) - // Release the seqlock if we acquired it earlier. + // Clear the write flag if we set it earlier. if locked { - mp.trace.seqlock.Add(1) + mp.trace.writing.Store(false) } } |