diff options
| -rw-r--r-- | Lib/subprocess.py | 2 | ||||
| -rw-r--r-- | Misc/NEWS | 4 |
2 files changed, 5 insertions, 1 deletions
diff --git a/Lib/subprocess.py b/Lib/subprocess.py index e7f39fef06..e79e5fd614 100644 --- a/Lib/subprocess.py +++ b/Lib/subprocess.py @@ -1601,7 +1601,7 @@ class Popen(object): selector.unregister(key.fileobj) key.fileobj.close() elif key.fileobj in (self.stdout, self.stderr): - data = os.read(key.fd, 4096) + data = os.read(key.fd, 32768) if not data: selector.unregister(key.fileobj) key.fileobj.close() @@ -24,6 +24,10 @@ Library - Issue #19343: Expose FreeBSD-specific APIs in resource module. Original patch by Koobs. +- Issue #19929: Call os.read with 32768 within subprocess.Popen.communicate + rather than 4096 for efficiency. A microbenchmark shows Linux and OS X + both using ~50% less cpu time this way. + - Issue #19506: Use a memoryview to avoid a data copy when piping data to stdin within subprocess.Popen.communicate. 5-10% less cpu usage. |