usertools: check 0-division with hugepage size

The default page size can be None, and the page size from user request
can be 0 kB if lower than 1024. In these cases, a division will fail.
In order to avoid a Python exception, the page size is checked
and an error message "Invalid page size" is printed.

A similar error message is printed in set_hugepages()
if the size is not supported, except at this stage the message can be
completed with "Valid page sizes".
Unfortunately the first check is too early to print such information.

A third error message can be printed in a different place (get_memsize)
in case of a format issue, e.g. a negative size.
The function get_memsize() is also used for total requested size,
so the error message "not a valid page size" was potentially wrong.
This message is replaced with the more general "is not a valid size".

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/usertools/dpdk-hugepages.py b/usertools/dpdk-hugepages.py
index fb368b6..db141b3 100755 (executable)
--- a/usertools/dpdk-hugepages.py
+++ b/usertools/dpdk-hugepages.py
@@ -29,7 +29,7 @@ def get_memsize(arg):
     '''Convert memory size with suffix to kB'''
     match = re.match(r'(\d+)([' + BINARY_PREFIX + r']?)$', arg.upper())
     if match is None:
-        sys.exit('{} is not a valid page size'.format(arg))
+        sys.exit('{} is not a valid size'.format(arg))
     num = float(match.group(1))
     suffix = match.group(2)
     if suffix == "":
@@ -254,6 +254,8 @@ To a complete setup of with 2 Gigabyte of 1G huge pages:
         pagesize_kb = get_memsize(args.pagesize)
     else:
         pagesize_kb = default_pagesize()
+    if not pagesize_kb:
+        sys.exit("Invalid page size: {}kB".format(pagesize_kb))
 
     if args.clear:
         clear_pages()