Re: [dpdk-dev] [Bug 725] hugepages.py script broken

[Stephen Hemminger <stephen@networkplumber.org>]

On Thu, 03 Jun 2021 15:08:52 +0000
bugzilla@dpdk.org wrote:

> https://bugs.dpdk.org/show_bug.cgi?id=725
> 
>             Bug ID: 725
>            Summary: hugepages.py script broken
>            Product: DPDK
>            Version: unspecified
>           Hardware: All
>                 OS: All
>             Status: UNCONFIRMED
>           Severity: normal
>           Priority: Normal
>          Component: other
>           Assignee: dev@dpdk.org
>           Reporter: harry.van.haaren@intel.com
>   Target Milestone: ---
> 
> Hi Folks,
> 
> It seems like the usertools/dpdk-hugepages.py script has changed/broken for
> certain systems. I've applied the below patch to see why it was calling
> "sys.exit()", which provides the following output;
> 
> $ usertools/dpdk-hugepages.py -p1G --setup 2G
> num pages 0 and pages 0
> num pages 1 and pages 0
> Unable to reserve required pages.
> num pages 0 and pages 0
> num pages 2 and pages 0
> Unable to reserve required pages.
> num pages 4 and pages 2
> Unable to reserve required pages.
> num pages 2 and pages 2
> 
> As we can see, it attempts multiple things, and then succeeds (DPDK runs and
> allocs hugepages as required after this).
> 
> Today the behavior will "fail" on the first "unable to reserve required pages"
> as 1 != 0, and does *not* continue attempting other pages sizes/things.
> 
> This check and "sys.exit()" was introduce in this commit:
> b25f0a7df80b620bab09dcb34bf4547d31ddede1
> 
> I'm not familiar with this script/hugepage reservation, so don't know what's a
> good fix. No owner of this script in MAINTAINERS either.
> 
> 
> diff --git a/usertools/dpdk-hugepages.py b/usertools/dpdk-hugepages.py
> index fb368b6933..0ef667c5f9 100755
> --- a/usertools/dpdk-hugepages.py
> +++ b/usertools/dpdk-hugepages.py
> @@ -68,8 +68,10 @@ def set_hugepages(path, pages):
>      except FileNotFoundError:
>          sys.exit("Invalid page size. Valid page sizes: {}".format(
>                   get_valid_page_sizes(path)))
> -    if get_hugepages(path) != pages:
> -        sys.exit('Unable to reserve required pages.')
> +    num_pages = get_hugepages(path)
> +    print("num pages {0} and pages {1}".format(num_pages, pages))
> +    if num_pages != pages:
> +        print('Unable to reserve required pages.')


If the number of hugepages is incorrect, please keep the exit call.
It is not correct to return success if there is an error in setup.