You should see a decrease in CPU with DCA on. If you run the ethregs utility from sourceforge and grep DCA you'll see that the lower 16 bits are configured differently for each cpu assigned an interrupt, when DCA is enabled.
Are you running with MSI-X enabled? There is another patch we can add which enables DCA for data of received packets, but you need to run a test which actually accesses the data (usually not benchmarks) Let me know if you're interested in applying this patch. Jesse -----Original Message----- From: Sangjin Han [mailto:[email protected]] Sent: Friday, June 19, 2009 12:21 PM To: [email protected] Subject: [E1000-devel] How can I make sure that ixgbe is working with DCA? I'm running an Intel 82598EB 10G AF DA on a Dell PowerEdge 1950 (Xeon 5430 + 5000X chipset). To enable DCA on my machine, I enabled I/OAT in BIOS and applied the patch(http://patchwork.kernel.org/patch/15273/) to the I/OAT driver. I confirmed that ixgbe_setup_dca() (in ixgbe 2.0.34.3) is done successfully. But I'm not sure whether DCA is working or not, because there is no change in throughput and CPU utilization. Is there any way to check if DCA works well with ixgbe? like some statistics or something. this is the result of ls /sys/class/dca lrwxrwxrwx 1 root root 0 Jun 20 03:12 dca0 -> ../../devices/pci0000:00/0000:00:08.0/dca/dca0 lrwxrwxrwx 1 root root 0 Jun 20 04:17 requester55 -> ../../devices/pci0000:00/0000:00:08.0/dca/dca0/requester55 How much performance gain can I expect with DCA? Is it insiginificant so that I can't see any change? ------------------------------------------------------------------------------ Are you an open source citizen? Join us for the Open Source Bridge conference! Portland, OR, June 17-19. Two days of sessions, one day of unconference: $250. Need another reason to go? 24-hour hacker lounge. Register today! http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org _______________________________________________ E1000-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/e1000-devel ------------------------------------------------------------------------------ Are you an open source citizen? Join us for the Open Source Bridge conference! Portland, OR, June 17-19. Two days of sessions, one day of unconference: $250. Need another reason to go? 24-hour hacker lounge. Register today! http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org _______________________________________________ E1000-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/e1000-devel
