lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <b8f675495a2c16cd742d1a95b3421ed15643aad2.camel@redhat.com>
Date: Wed, 31 Jan 2024 19:39:41 +0100
From: Paolo Abeni <pabeni@...hat.com>
To: Willem de Bruijn <willemdebruijn.kernel@...il.com>, Jakub Kicinski
	 <kuba@...nel.org>
Cc: netdev@...r.kernel.org, davem@...emloft.net, edumazet@...gle.com, 
	linux-kselftest@...r.kernel.org, Willem de Bruijn <willemb@...gle.com>
Subject: Re: [PATCH net-next] selftests/net: calibrate txtimestamp

On Wed, 2024-01-31 at 10:06 -0500, Willem de Bruijn wrote:
> Otherwise I'll start with the gro and so-txtime tests. They may not
> be so easily calibrated. As we cannot control the gro timeout, nor
> the FQ max horizon.

Note that we can control the GRO timeout to some extent, via 
gro_flush_timeout, see commit 89abe628375301fedb68770644df845d49018d8b.

Unfortunately that is not enough for 'large' gro tests. I think the
root cause is that the process sending the packets can be de-scheduled
- even the qemu VM from the hypervisor CPU - causing an extremely large
gap between consecutive pkts.

I guess/hope that replacing multiple sendmsg() with a sendmmsg() could
improve a bit the scenario, but I fear it will not solve the issue
completely.

> In such cases we can use the environment variable to either skip the
> test entirely or --my preference-- run it to get code coverage, but
> suppress a failure if due to timing (only). Sounds good?

Sounds good to me! I was wondering about skipping the 'large' test
only, but suppressing the failure when KSFT_MACHINE_SLOW=yes only for
such test looks a better option.

Thanks!

Paolo


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ