Hello Jesse and others, I have a Dell R610 with 82575GB nics and would like to enable DCA (i assume this is beneficial as this server will handle a huge amount of small packets). I/OAT is enabled the BIOS, but:
ioatdma 0000:00:16.0: DCA is disabled in BIOS Can DCA still be enabled? If so, which patch should i use? Btw: on Dell servers it is possible to disable prefetchers. Driver details: driver: igb version: 1.3.16-k2 firmware-version: 1.7-7 bus-info: 0000:06:00.0 Thanks. Patrick Schreurs Brandeburg, Jesse wrote: > 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 ------------------------------------------------------------------------------ _______________________________________________ E1000-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/e1000-devel
