mbox series

[net-next,0/6] selftests: net: page_poll allocation error injection

Message ID 20240426232400.624864-1-kuba@kernel.org (mailing list archive)
Headers show
Series selftests: net: page_poll allocation error injection | expand

Message

Jakub Kicinski April 26, 2024, 11:23 p.m. UTC
Add a test for exercising driver memory allocation failure paths.
page pool is a bit tricky to inject errors into at the page allocator
level because of the bulk alloc and recycling, so add explicit error
injection support "in front" of the caches.

Add a test to exercise that using only the standard APIs.
This is the first useful test for the new tests with an endpoint.
There's no point testing netdevsim here, so this is also the first
HW-only test in Python.

I'm not super happy with the traffic generation using iperf3,
my initial approach was to use mausezahn. But it turned out to be
5x slower in terms of PPS. Hopefully this is good enough for now.

Jakub Kicinski (6):
  net: page_pool: support error injection
  selftests: drv-net-hw: support using Python from net hw tests
  selftests: net: py: extract tool logic
  selftests: net: py: avoid all ports < 10k
  selftests: drv-net: support generating iperf3 load
  selftests: drv-net-hw: add test for memory allocation failures with
    page pool

 net/core/page_pool.c                          |   2 +
 tools/testing/selftests/Makefile              |   2 +-
 .../testing/selftests/drivers/net/hw/Makefile |   2 +
 .../drivers/net/hw/lib/py/__init__.py         |  16 +++
 .../selftests/drivers/net/hw/pp_alloc_fail.py | 129 ++++++++++++++++++
 .../selftests/drivers/net/lib/py/__init__.py  |   1 +
 .../selftests/drivers/net/lib/py/env.py       |  10 +-
 .../selftests/drivers/net/lib/py/load.py      |  41 ++++++
 tools/testing/selftests/net/lib/py/ksft.py    |   4 +
 tools/testing/selftests/net/lib/py/utils.py   |  14 +-
 10 files changed, 214 insertions(+), 7 deletions(-)
 create mode 100644 tools/testing/selftests/drivers/net/hw/lib/py/__init__.py
 create mode 100755 tools/testing/selftests/drivers/net/hw/pp_alloc_fail.py
 create mode 100644 tools/testing/selftests/drivers/net/lib/py/load.py

Comments

Willem de Bruijn April 27, 2024, 1:55 p.m. UTC | #1
Jakub Kicinski wrote:
> Add a test for exercising driver memory allocation failure paths.
> page pool is a bit tricky to inject errors into at the page allocator
> level because of the bulk alloc and recycling, so add explicit error
> injection support "in front" of the caches.
> 
> Add a test to exercise that using only the standard APIs.
> This is the first useful test for the new tests with an endpoint.
> There's no point testing netdevsim here, so this is also the first
> HW-only test in Python.
> 
> I'm not super happy with the traffic generation using iperf3,
> my initial approach was to use mausezahn. But it turned out to be
> 5x slower in terms of PPS. Hopefully this is good enough for now.
> 
> Jakub Kicinski (6):
>   net: page_pool: support error injection
>   selftests: drv-net-hw: support using Python from net hw tests
>   selftests: net: py: extract tool logic
>   selftests: net: py: avoid all ports < 10k
>   selftests: drv-net: support generating iperf3 load
>   selftests: drv-net-hw: add test for memory allocation failures with
>     page pool

Reviewed-by: Willem de Bruijn <willemb@google.com>
Andrew Lunn April 29, 2024, 3:01 p.m. UTC | #2
> I'm not super happy with the traffic generation using iperf3,
> my initial approach was to use mausezahn. But it turned out to be
> 5x slower in terms of PPS. Hopefully this is good enough for now.

How important is PPS? In order to get 'Maintained' status, automotive
vendors are going to want to test their 10Mbps T1 links.

	Andrew
Jakub Kicinski April 29, 2024, 4:25 p.m. UTC | #3
On Mon, 29 Apr 2024 17:01:55 +0200 Andrew Lunn wrote:
> > I'm not super happy with the traffic generation using iperf3,
> > my initial approach was to use mausezahn. But it turned out to be
> > 5x slower in terms of PPS. Hopefully this is good enough for now.  
> 
> How important is PPS? In order to get 'Maintained' status, automotive
> vendors are going to want to test their 10Mbps T1 links.

s/Maintained/Supported/ ?

PPS isn't important in itself, that said, I wanted to set a floor to
make sure that the failure path is actually well exercised. 
Some drivers may be doing internal recycling or whatever other magic,
which would make them barely call the page_pool alloc.

Even though this is not a performance tests the check is based on
expected perf. My thinking is that once we have some data points about
various system we can abstract the perf expectations a bit more
systematically than if speed < 10GE: pps //= 10