On Mon, Nov 23, 2020 at 03:26:11PM +0000, Stefan Chulski wrote: > > -----Original Message----- > > From: Russell King - ARM Linux admin <[email protected]> > > Sent: Monday, November 23, 2020 5:11 PM > > To: Stefan Chulski <[email protected]> > > Cc: [email protected]; [email protected]; > > [email protected]; Nadav Haklai <[email protected]>; Yan Markman > > <[email protected]>; [email protected]; [email protected]; > > [email protected]; [email protected]; [email protected] > > Subject: [EXT] Re: [PATCH v1] net: mvpp2: divide fifo for dts-active ports > > only > > > > External Email > > > > ---------------------------------------------------------------------- > > Hi, > > > > On Mon, Nov 23, 2020 at 04:52:40PM +0200, [email protected] wrote: > > > From: Stefan Chulski <[email protected]> > > > > > > Tx/Rx FIFO is a HW resource limited by total size, but shared by all > > > ports of same CP110 and impacting port-performance. > > > Do not divide the FIFO for ports which are not enabled in DTS, so > > > active ports could have more FIFO. > > > > > > The active port mapping should be done in probe before FIFO-init. > > > > It would be nice to know what the effect is from this - is it a small or > > large > > boost in performance? > > I didn't saw any significant improvement with LINUX bridge or forwarding, but > this reduced PPv2 overruns drops, reduced CRC sent errors with DPDK user > space application. > So this improved zero loss throughput. Probably with XDP we would see a > similar effect. > > > What is the effect when the ports on a CP110 are configured for 10G, 1G, and > > 2.5G in that order, as is the case on the Macchiatobin board? > > Macchiatobin has two CP's. CP1 has 3 ports, so the distribution of FIFO > would be the same as before. > On CP0 which has a single port, all FIFO would be allocated for 10G port.
Your code allocates for CP1: 32K to port 0 (the 10G port on Macchiatobin) 8K to port 1 (the 1G dedicated ethernet port on Macchiatobin) 4K to port 2 (the 1G/2.5G SFP port on Macchiatobin) I'm questioning that allocation for port 1 and 2. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
