#708: use buffering for open() only on Python 2; on Python 3 this doe…

…s not have any effect so it's better to let python decide what to do

HISTORY.rst

@@ -3,15 +3,15 @@ Bug tracker at https://github.com/giampaolo/psutil/issues
 3.3.1 - XXXX-XX-XX
 ==================
 
-**Bug fixes**
+**Enhancements**
 
-- #714: [OpenBSD] virtual_memory().cached value was always set to 0.
+- #708: [Linux] psutil.net_connections() and Process.connections() on Python 2
+  can be up to 3x faster in case of many connections.
+  Also psutil.Process.memory_maps() is slightly faster.
 
-**Enhancements**
+**Bug fixes**
 
-- 708: [Linux] psutil.net_connections() and Process.connections() can be up to
-  3x faster in case of many connections. Also psutil.Process.memory_maps()
-  is slightly faster.
+- #714: [OpenBSD] virtual_memory().cached value was always set to 0.
 
 
 3.3.0 - 2015-11-25

psutil/_pslinux.py

@@ -63,15 +63,18 @@
 CLOCK_TICKS = os.sysconf("SC_CLK_TCK")
 PAGESIZE = os.sysconf("SC_PAGE_SIZE")
 BOOT_TIME = None  # set later
-BIGGER_FILE_BUFFERING = 8192
+# Used when reading "big" files, namely /proc/{pid}/smaps and /proc/net/*.
+# On Python 2, using a buffer with open() for such files may result in a
+# speedup, see: https://github.com/giampaolo/psutil/issues/708
+BIGGER_FILE_BUFFERING = -1 if PY3 else 8192
 LITTLE_ENDIAN = sys.byteorder == 'little'
 if PY3:
     FS_ENCODING = sys.getfilesystemencoding()
 if enum is None:
     AF_LINK = socket.AF_PACKET
 else:
     AddressFamily = enum.IntEnum('AddressFamily',
-                                 {'AF_LINK': socket.AF_PACKET})
+                                 {'AF_LINK': int(socket.AF_PACKET)})
     AF_LINK = AddressFamily.AF_LINK
 
 # ioprio_* constants http://linux.die.net/man/2/ioprio_get