From mboxrd@z Thu Jan 1 00:00:00 1970 From: peppe.cavallaro@st.com (Giuseppe CAVALLARO) Date: Thu, 23 Mar 2017 11:48:38 +0100 Subject: stmmac: Performance regression after commit aff3d9eff843 "net: stmmac: enable multiple buffers" In-Reply-To: References: <20170323100828.GC16625@Red> <68200e05-04fd-1cc1-f6d6-f77e9e6f1d9d@synopsys.com> <20170323102037.GD16625@Red> Message-ID: <465dc72e-8a1f-b41f-105f-add2164df6d5@st.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello On 3/23/2017 11:20 AM, Corentin Labbe wrote: >> I have a 4.21 QoS Core with 4 RX + 4 TX and detected no regression. >> >Could you please share the iperf cmds you are using in order for me to reproduce >> >in my side? Joao, you have a really powerful HW integration with multiple channels for both RX and TX. Often this is not the same for other setup where, usually just a DMA0 is present or, sometime, there is just one RX extra channel. My question is, what happens on this kind of configurations? Are we still guarantying the best performances? Also we have to guarantee, that the TSO and SG are always working. Another point is the buffer sizes that can be different among platforms. The problem below reported by Corentin push me to think that there is a bug, so we should understand when this has been introduced and if likely fixed by some configuration we are not take care right now. ndesc_get_rx_status: Oversized frame spanned multiple buffers" Best Regards Peppe