From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Brivio To: passt-dev@passt.top Subject: [PATCH] test/README: Requirements for socket buffer sizes and hardware performance events Date: Tue, 30 Aug 2022 22:00:07 +0200 Message-ID: <20220830200007.3065472-1-sbrivio@redhat.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="===============8136698000041424490==" --===============8136698000041424490== Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Performance tests use iperf3(1) with large windows, and these sysctl entries are needed to run them unmodified. The passt demo uses perf(1) to report syscall overhead, and that needs access to hardware performance counters for unprivileged users. Reported-by: David Gibson Signed-off-by: Stefano Brivio --- test/README.md | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/test/README.md b/test/README.md index 581949a..72a4986 100644 --- a/test/README.md +++ b/test/README.md @@ -47,6 +47,22 @@ Virtual machine images are built during test executions us= ing [mbuto](https://mbuto.lameexcu.se/), the shell script is sourced via _git_ as needed, so there's no need to actually install it. =20 +### Kernel parameters + +Performance tests use iperf3 with rather large TCP receiving and sending +windows, to decrease the likelihood of iperf3 itself becoming the bottleneck. +These values need to be allowed by the kernel of the host running the tests. +Example for /etc/sysctl.conf: + + net.core.rmem_max =3D 134217728 + net.core.wmem_max =3D 134217728 + +Further, the passt demo uses perf(1), relying on hardware events for perform= ance +counters, to display syscall overhead. The kernel needs to allow unprivileged +users to access these events. Suggested entry for /etc/sysctl.conf: + + kernel.perf_event_paranoid =3D -1 + ### Special requirements for continuous integration and demo modes =20 Running the test suite as continuous integration or demo modes will record t= he --=20 2.35.1 --===============8136698000041424490==--