Hugepages: on the fly allocation.

If no hugepages are available, try to allocate HUGEPAGE_RAM_ALLOCATION
amount of RAM for hugepages.
JIRA: VSPERF-290

Change-Id: I092b3831254579eeebbe45e85884828f9d749895
Signed-off-by: Mars Toktonaliev <mars.toktonaliev@nokia.com>

3 files changed, 54 insertions, 1 deletions

diff --git a/conf/02_vswitch.conf b/conf/02_vswitch.conf
index 79f0afbd..e5736138 100644
--- a/conf/02_vswitch.conf
+++ b/conf/02_vswitch.conf
@@ -100,6 +100,11 @@ VSWITCH_BRIDGE_NAME = 'br0'
 # directory where hugepages will be mounted on system init
 HUGEPAGE_DIR = '/dev/hugepages'
 
+# If no hugepages are available, try to allocate HUGEPAGE_RAM_ALLOCATION.
+# Default is 2 x 1048576 = 2097152 kB.
+# 10 GB (10485760 kB) or more is recommended for PVP & PVVP testing scenarios.
+HUGEPAGE_RAM_ALLOCATION = 2097152
+
 # Sets OVS PMDs core mask to 30 for affinitization to 5th and 6th CPU core.
 # Note that the '0x' notation should not be used.
 VSWITCH_PMD_CPU_MASK = '30'
diff --git a/docs/configguide/installation.rst b/docs/configguide/installation.rst
index 5072dee0..1755ca6f 100755
--- a/docs/configguide/installation.rst
+++ b/docs/configguide/installation.rst
@@ -190,3 +190,8 @@ You can review your hugepage amounts by executing the following command
 .. code:: bash
 
     cat /proc/meminfo | grep Huge
+
+If no hugepages are available vsperf will try to automatically allocate some.
+Allocation is controlled by HUGEPAGE_RAM_ALLOCATION configuration parameter in
+``02_vswitch.conf`` file. Default is 2GB, resulting in either 2 1GB hugepages
+or 1024 2MB hugepages.
diff --git a/tools/hugepages.py b/tools/hugepages.py
index 3a434d6e..119f94b5 100644
--- a/tools/hugepages.py
+++ b/tools/hugepages.py
@@ -20,6 +20,7 @@ import re
 import subprocess
 import logging
 import locale
+import math
 
 from tools import tasks
 from conf import settings
@@ -30,6 +31,46 @@ _LOGGER = logging.getLogger(__name__)
 # hugepage management
 #
 
+def get_hugepage_size():
+    """Return the size of the configured hugepages
+    """
+    hugepage_size_re = re.compile(r'^Hugepagesize:\s+(?P<size_hp>\d+)\s+kB',
+                                  re.IGNORECASE)
+    with open('/proc/meminfo', 'r') as fh:
+        data = fh.readlines()
+        for line in data:
+            match = hugepage_size_re.search(line)
+            if match:
+                _LOGGER.info('Hugepages size: %s', match.group('size_hp'))
+                return int(match.group('size_hp'))
+        else:
+            _LOGGER.error('Could not parse for hugepage size')
+            return 0
+
+
+
+def allocate_hugepages():
+    """Allocate hugepages on the fly
+    """
+    hp_size = get_hugepage_size()
+
+    if hp_size > 0:
+        nr_hp = int(math.ceil(settings.getValue('HUGEPAGE_RAM_ALLOCATION')/hp_size))
+        _LOGGER.info('Will allocate %s hugepages.', nr_hp)
+
+        nr_hugepages = 'vm.nr_hugepages=' + str(nr_hp)
+        try:
+            tasks.run_task(['sudo', 'sysctl', nr_hugepages],
+                           _LOGGER, 'Trying to allocate hugepages..', True)
+        except subprocess.CalledProcessError:
+            _LOGGER.error('Unable to allocate hugepages.')
+            return False
+        return True
+
+    else:
+        _LOGGER.error('Division by 0 will be supported in next release')
+        return False
+
 
 def is_hugepage_available():
     """Check if hugepages are available on the system.
@@ -47,8 +88,10 @@ def is_hugepage_available():
             continue
 
         num_huge = result.group('num_hp')
-        if not num_huge:
+        if num_huge == '0':
             _LOGGER.info('No free hugepages.')
+            if not allocate_hugepages():
+                return False
         else:
             _LOGGER.info('Found \'%s\' free hugepage(s).', num_huge)
         return True