On 11/20/2012 03:59 PM, Alexander Duyck wrote: > On 11/20/2012 02:56 PM, Ben Greear wrote: >> We are trying out some new hardware, but it's not able to go above about >> 4Gbps in each direction >> (using modified pktgen). The two ixgbe ports are cabled to each other. >> >> Ethernet controller: >> >> 03:00.0 Ethernet controller: Intel Corporation 82599EB 10-Gigabit SFI/SFP+ >> Network Connection (rev 01) >> 03:00.1 Ethernet controller: Intel Corporation 82599EB 10-Gigabit SFI/SFP+ >> Network Connection (rev 01) >> >> CPU: >> >> Intel(R) Xeon(R) CPU E5-2643 0 @ 3.30GHz >> >> dmesg shows it is using 5GT/s: >> >> ixgbe 0000:03:00.0: (PCI Express:5.0GT/s:Width x8) 00:e0:ed:1e:d4:dc >> >> >> On similar setup (and same kernel) with i7 or e3 processor systems it runs >> right at 10Gbps bi-directional. >> >> Is the E5-2643 just not that fast of a processor, or should I expect >> better performance? >> >> Thanks, >> Ben >> > > What is the driver and kernel you are testing this with?
kernel 3.5.7+, standard in-kernel driver. > Also, have you checked to make sure the feature set is comparable? For > instance the E5 can support VT-d. If that is enabled it can have a > negative impact on I/O performance due to extra locking overhead for > map/unmap calls on the host. I'll go poke around the BIOS and disable the VT-d if I can find it. > Assuming you are running a recent kernel with support for the "perf" > command you might do a quick "perf top" while running your test to see > what pops up as consuming most of your CPU time. Here's what perf top shows. I'm not sure what this indicates. Samples: 355K of event 'cycles', Event count (approx.): 77649034661 10.64% [kernel] [k] rb_prev 9.89% [kernel] [k] clflush_cache_range 5.92% [kernel] [k] alloc_iova 4.77% [kernel] [k] do_raw_spin_lock 4.57% [kernel] [k] __domain_mapping 3.95% [ixgbe] [k] ixgbe_poll 3.87% [kernel] [k] native_read_tsc 3.24% [pktgen] [k] pktgen_thread_worker 2.48% [ixgbe] [k] ixgbe_xmit_frame_ring 2.21% perf-3391.map [.] 0x00007f14dd89760c 2.15% [kernel] [k] timekeeping_get_ns 2.14% [kernel] [k] sub_preempt_count 2.06% [kernel] [k] do_raw_spin_unlock 2.05% [kernel] [k] add_preempt_count 1.95% [kernel] [k] find_iova Thanks, Ben -- Ben Greear <[email protected]> Candela Technologies Inc http://www.candelatech.com ------------------------------------------------------------------------------ Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov _______________________________________________ E1000-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
