merge from master756-disk-io-busy-time

5 files changed, 61 insertions, 22 deletions

diff --git a/HISTORY.rst b/HISTORY.rst
index c76e4a9a..8e9e6b32 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -5,6 +5,7 @@ Bug tracker at https://github.com/giampaolo/psutil/issues
 
 **Enhancements**
 
+- #523: [Linux] disk_io_counters() return a new "busy_time" field.
 - #660: [Windows] make.bat is smarter in finding alternative VS install
   locations.  (patch by mpderbec)
 - #732: Process.environ().  (patch by Frank Benkstein)
diff --git a/docs/index.rst b/docs/index.rst
index 94cc623d..b49570be 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -266,7 +266,29 @@ Disks
 .. function:: disk_io_counters(perdisk=False)
 
   Return system-wide disk I/O statistics as a namedtuple including the
-  following fields:
+  following fields.
+
+  +--------------------+-------------+-------------+-------------+-------------+-------------+-------------+
+  | Linux              | OSX         | Solaris     | Windows     | FreeBSD     | OpenBSD     | NetBSD      |
+  +====================+=============+=============+=============+=============+=============+=============+
+  | read_count         | read_count  | read_count  | read_count  | read_count  | read_count  | read_count  |
+  +--------------------+-------------+-------------+-------------+-------------+-------------+-------------+
+  | write_count        | write_count | write_count | write_count | write_count | write_count | write_count |
+  +--------------------+-------------+-------------+-------------+-------------+-------------+-------------+
+  | read_bytes         | read_bytes  | read_bytes  | read_bytes  | read_bytes  | read_bytes  | read_bytes  |
+  +--------------------+-------------+-------------+-------------+-------------+-------------+-------------+
+  | write_bytes        | write_bytes | write_bytes | write_bytes | write_bytes | write_bytes | write_bytes |
+  +--------------------+-------------+-------------+-------------+-------------+-------------+-------------+
+  | read_time          | read_time   | read_time   | read_time   | read_time   | read_time   |             |
+  +--------------------+-------------+-------------+-------------+-------------+-------------+-------------+
+  | write_time         | write_time  | write_time  | write_time  | write_time  | write_time  |             |
+  +--------------------+-------------+-------------+-------------+-------------+-------------+-------------+
+  | read_merged_count  |             |             |             |             |             |             |
+  +--------------------+-------------+-------------+-------------+-------------+-------------+-------------+
+  | write_merged_count |             |             |             |             |             |             |
+  +--------------------+-------------+-------------+-------------+-------------+-------------+-------------+
+  | busy_time          |             |             |             |             |             |             |
+  +--------------------+-------------+-------------+-------------+-------------+-------------+-------------+
 
   - **read_count**: number of reads
   - **write_count**: number of writes
@@ -274,9 +296,7 @@ Disks
   - **write_bytes**: number of bytes written
   - **read_time**: time spent reading from disk (in milliseconds)
   - **write_time**: time spent writing to disk (in milliseconds)
-
-  On Linux we get the following extra fields:
-
+  - **busy_time**: (Linux) time spent doing actual I/Os (in milliseconds)
   - **read_merged_count** (Linux): number of merged reads (see `iostat doc <https://www.kernel.org/doc/Documentation/iostats.txt>`__).
   - **write_merged_count** (Linux): number of merged writes (see `iostat doc <https://www.kernel.org/doc/Documentation/iostats.txt>`__).
 
@@ -295,8 +315,8 @@ Disks
      'sda2': sdiskio(read_count=18707, write_count=8830, read_bytes=6060, write_bytes=3443, read_time=24585, write_time=1572),
      'sdb1': sdiskio(read_count=161, write_count=0, read_bytes=786432, write_bytes=0, read_time=44, write_time=0)}
 
-  .. versionchanged:: 4.0.0 *read_merged_count* and *write_merged_count* were
-     addded on Linux.
+  .. versionchanged:: 4.0.0 *busy_time*, *read_merged_count* and
+     *write_merged_count* were addded on Linux.
 
 Network
 -------
diff --git a/psutil/_pslinux.py b/psutil/_pslinux.py
index d80dfba2..3ffdf25c 100644
--- a/psutil/_pslinux.py
+++ b/psutil/_pslinux.py
@@ -179,6 +179,20 @@ def readlink(path):
     return path
 
 
+def get_sector_size():
+    try:
+        with open(b"/sys/block/sda/queue/hw_sector_size") as f:
+            return int(f.read())
+    except (IOError, ValueError):
+        # man iostat states that sectors are equivalent with blocks and
+        # have a size of 512 bytes since 2.4 kernels. This value is
+        # needed to calculate the amount of disk I/O in bytes.
+        return 512
+
+
+SECTOR_SIZE = get_sector_size()
+
+
 # --- named tuples
 
 @memoize
@@ -220,7 +234,8 @@ svmem = namedtuple(
 sdiskio = namedtuple('sdiskio', ['read_count', 'write_count',
                                  'read_bytes', 'write_bytes',
                                  'read_time', 'write_time',
-                                 'read_merged_count', 'write_merged_count'])
+                                 'read_merged_count', 'write_merged_count',
+                                 'busy_time'])
 
 pmem = namedtuple('pmem', 'rss vms shared text lib data dirty')
 paddrspmem = namedtuple('paddrspmem', ['uss', 'pss', 'swap'])
@@ -731,11 +746,6 @@ def disk_io_counters():
     """Return disk I/O statistics for every disk installed on the
     system as a dict of raw tuples.
     """
-    # man iostat states that sectors are equivalent with blocks and
-    # have a size of 512 bytes since 2.4 kernels. This value is
-    # needed to calculate the amount of disk I/O in bytes.
-    SECTOR_SIZE = 512
-
     # determine partitions we want to look for
     def get_partitions():
         partitions = []
@@ -773,6 +783,7 @@ def disk_io_counters():
         # "3    1   hda1 8 8 8 8"
         # See:
         # https://www.kernel.org/doc/Documentation/iostats.txt
+        # https://www.kernel.org/doc/Documentation/ABI/testing/procfs-diskstats
         fields = line.split()
         fields_len = len(fields)
         if fields_len == 15:
@@ -780,17 +791,17 @@ def disk_io_counters():
             name = fields[3]
             reads = int(fields[2])
             (reads_merged, rbytes, rtime, writes, writes_merged,
-                wbytes, wtime) = map(int, fields[4:11])
+                wbytes, wtime, _, busy_time, _) = map(int, fields[4:14])
         elif fields_len == 14:
             # Linux 2.6+, line referring to a disk
             name = fields[2]
             (reads, reads_merged, rbytes, rtime, writes, writes_merged,
-                wbytes, wtime) = map(int, fields[3:11])
+                wbytes, wtime, _, busy_time, _) = map(int, fields[3:14])
         elif fields_len == 7:
             # Linux 2.6+, line referring to a partition
             name = fields[2]
             reads, rbytes, writes, wbytes = map(int, fields[3:])
-            rtime = wtime = reads_merged = writes_merged = 0
+            rtime = wtime = reads_merged = writes_merged = busy_time = 0
         else:
             raise ValueError("not sure how to interpret line %r" % line)
 
@@ -798,7 +809,7 @@ def disk_io_counters():
             rbytes = rbytes * SECTOR_SIZE
             wbytes = wbytes * SECTOR_SIZE
             retdict[name] = (reads, writes, rbytes, wbytes, rtime, wtime,
-                             reads_merged, writes_merged)
+                             reads_merged, writes_merged, busy_time)
     return retdict
 
 
diff --git a/psutil/tests/test_linux.py b/psutil/tests/test_linux.py
index 1d19eff6..149b0f51 100644
--- a/psutil/tests/test_linux.py
+++ b/psutil/tests/test_linux.py
@@ -49,6 +49,8 @@ HERE = os.path.abspath(os.path.dirname(__file__))
 SIOCGIFADDR = 0x8915
 SIOCGIFCONF = 0x8912
 SIOCGIFHWADDR = 0x8927
+if LINUX:
+    SECTOR_SIZE = psutil._psplatform.SECTOR_SIZE
 
 
 # =====================================================================
@@ -423,12 +425,13 @@ class TestSystemDisks(unittest.TestCase):
             assert m.called
             self.assertEqual(ret.read_count, 1)
             self.assertEqual(ret.read_merged_count, 2)
-            self.assertEqual(ret.read_bytes, 3 * 512)
+            self.assertEqual(ret.read_bytes, 3 * SECTOR_SIZE)
             self.assertEqual(ret.read_time, 4)
             self.assertEqual(ret.write_count, 5)
             self.assertEqual(ret.write_merged_count, 6)
-            self.assertEqual(ret.write_bytes, 7 * 512)
+            self.assertEqual(ret.write_bytes, 7 * SECTOR_SIZE)
             self.assertEqual(ret.write_time, 8)
+            self.assertEqual(ret.busy_time, 10)
 
     def test_disk_io_counters_kernel_2_6_full_mocked(self):
         # Tests /proc/diskstats parsing format for 2.6 kernels,
@@ -455,12 +458,13 @@ class TestSystemDisks(unittest.TestCase):
             assert m.called
             self.assertEqual(ret.read_count, 1)
             self.assertEqual(ret.read_merged_count, 2)
-            self.assertEqual(ret.read_bytes, 3 * 512)
+            self.assertEqual(ret.read_bytes, 3 * SECTOR_SIZE)
             self.assertEqual(ret.read_time, 4)
             self.assertEqual(ret.write_count, 5)
             self.assertEqual(ret.write_merged_count, 6)
-            self.assertEqual(ret.write_bytes, 7 * 512)
+            self.assertEqual(ret.write_bytes, 7 * SECTOR_SIZE)
             self.assertEqual(ret.write_time, 8)
+            self.assertEqual(ret.busy_time, 10)
 
     def test_disk_io_counters_kernel_2_6_limited_mocked(self):
         # Tests /proc/diskstats parsing format for 2.6 kernels,
@@ -488,14 +492,15 @@ class TestSystemDisks(unittest.TestCase):
             ret = psutil.disk_io_counters()
             assert m.called
             self.assertEqual(ret.read_count, 1)
-            self.assertEqual(ret.read_bytes, 2 * 512)
+            self.assertEqual(ret.read_bytes, 2 * SECTOR_SIZE)
             self.assertEqual(ret.write_count, 3)
-            self.assertEqual(ret.write_bytes, 4 * 512)
+            self.assertEqual(ret.write_bytes, 4 * SECTOR_SIZE)
 
             self.assertEqual(ret.read_merged_count, 0)
             self.assertEqual(ret.read_time, 0)
             self.assertEqual(ret.write_merged_count, 0)
             self.assertEqual(ret.write_time, 0)
+            self.assertEqual(ret.busy_time, 0)
 
 
 # =====================================================================
diff --git a/psutil/tests/test_system.py b/psutil/tests/test_system.py
index 3fd6876a..1b6127f9 100644
--- a/psutil/tests/test_system.py
+++ b/psutil/tests/test_system.py
@@ -615,8 +615,10 @@ class TestSystemAPIs(unittest.TestCase):
             if LINUX:
                 self.assertEqual(nt[6], nt.read_merged_count)
                 self.assertEqual(nt[7], nt.write_merged_count)
+                self.assertEqual(nt[8], nt.busy_time)
                 assert nt.read_merged_count >= 0, nt
                 assert nt.write_merged_count >= 0, nt
+                assert nt.busy_time >= 0, nt
             elif BSD:
                 self.assertEqual(nt[6], nt.busy_time)
                 assert nt.busy_time >= 0, nt