Date: Tue, 26 Feb 2019 22:21:23 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 236067] [em] Intel 82574L can not turn off flow control Message-ID: <bug-236067-227@https.bugs.freebsd.org/bugzilla/>
next in thread | raw e-mail | index | archive | help
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D236067 Bug ID: 236067 Summary: [em] Intel 82574L can not turn off flow control Product: Base System Version: CURRENT Hardware: amd64 OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: lev@FreeBSD.org I have two systems with 82574L NICs. One, name it G (for "generator"), is powerful enough to saturate almost 1G links with small packets (more than 1100Kpps). Other, name it DUT is underpowered and can not process such packet rate. Both G and dut have "set dev.em.0.fc=3D0". G try to generate traffic to DUT's MAC with netmap & pkt-gen. If G and DUT = are connected (no matter how: with direct patchcord or via dedicated switch) G could generate only as much packets as DUT could process! If I remove DUT f= rom dedicated switch, G generates almost-line-rate PPS. If I replace DUT with o= ther system with I210 NIC, G generates same high PPS even if system with I210 can not process it. Looks like 82574L can not turn off flow control. Once again: 82574L -> Switch -> 82574L - pkt-gen generates PPS limited by receiver. 82574L -> 82574L - pkt-gen generates PPS limited by receiver. 82574L -> Switch -> "blackhole" (no other devices attached to switch) - pkt= -gen generates line-rate PPS. 82574L -> I210 - pkt-gen generates line-rate PPS. 82574L -> Switch -> I210 - pkt-gen generates line-rate PPS. --=20 You are receiving this mail because: You are the assignee for the bug.=
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-236067-227>