** Description changed: - This crash was submitted upstream and a fix was already present, but it - didn't land until the 3.19 kernel. This bug is to track getting that fix - into trusty and utopic. + [Impact] + System panics every few hours under constant network load - Unable to handle kernel NULL pointer dereference at virtual address 000000c0 - pgd = ffffffc3e639a000 - [000000c0] *pgd=00000043e629d003, *pud=00000043e629d003, *pmd=0000000000000000 - Internal error: Oops: 96000006 [#1] PREEMPT SMP - Modules linked in: - CPU: 0 PID: 6643 Comm: qemu-system-aar Not tainted 3.19.0-rc7+ #254 - Hardware name: APM X-Gene Mustang board (DT) - task: ffffffc3ee3aee00 ti: ffffffc3c044c000 task.ti: ffffffc3c044c000 - PC is at xgene_enet_process_ring+0x94/0x328 - LR is at xgene_enet_process_ring+0x78/0x328 - pc : [<ffffffc0003f9058>] lr : [<ffffffc0003f903c>] pstate: 80000145 - sp : ffffffc3c044fa00 - x29: ffffffc3c044fa00 x28: ffffffc0fe8aa218 - x27: 0000000000000000 x26: 0000000000000000 - x25: ffffffc3ee2b7000 x24: 0000000000000040 - x23: ffffffc0fe8aa418 x22: 00000000000001ff - x21: 0000000000000001 x20: ffffffc0ff058380 - x19: 000000000000001c x18: 0000007f82d1c1f0 - x17: 0000007f84afbc90 x16: ffffffc0001a6a8c - x15: 0000007f84b805a0 x14: 0000000000000000 - x13: 00000000d0d03820 x12: 0000000000000000 - x11: 0000000000000024 x10: 00000000d0d30a20 - x9 : ffffffc00031da28 x8 : ffffffbdc0000000 - x7 : ffffffc3cae0285e x6 : 00000040fec00000 - x5 : 0c08100801400148 x4 : 00000040ff000000 - x3 : 00020000000000d1 x2 : 0000000000000066 - x1 : 00000043cae0285e x0 : ffffffc3ee2bb818 + [Test Case] + On the X-Gene system, start an iperf server: + $ iperf -s + Connect to it from another system (1Gbps is sufficient) + $ iperf -t 100000 -c <xgene host> - Process qemu-system-aar (pid: 6643, stack limit = 0xffffffc3c044c058) - Stack: (0xffffffc3c044fa00 to 0xffffffc3c0450000) - fa00: c044fa70 ffffffc3 003f93d0 ffffffc0 fe8aa290 ffffffc0 00000000 00000000 - fa20: 00000040 00000000 0078e000 ffffffc0 0016cac3 00000001 c044fb20 ffffffc3 - fa40: ff7d4000 00000003 007825c0 ffffffc0 0000012c 00000000 fff565c0 ffffffc3 - fa60: ffffffc0 00000000 ee2b7000 ffffffc3 c044faa0 ffffffc3 004a5cec ffffffc0 - fa80: fe8aa290 ffffffc0 00000000 00000000 00000040 00000000 84b805a0 0000007f - faa0: c044fb40 ffffffc3 000b5da0 ffffffc0 c044c000 ffffffc3 0078e000 ffffffc0 - fac0: 0077faa0 ffffffc0 c044fb40 ffffffc3 00000018 00000000 00000101 00000000 - fae0: 00000003 00000000 0078e0c0 ffffffc0 0078e0d8 ffffffc0 00000000 00000000 - fb00: 00000008 00000000 006fbd90 ffffffc0 006fb9f0 ffffffc0 007e3d74 ffffffc0 - fb20: c044fb20 ffffffc3 c044fb20 ffffffc3 c044fb30 ffffffc3 c044fb30 ffffffc3 - fb40: c044fbc0 ffffffc3 000b6134 ffffffc0 00780000 ffffffc0 00000000 00000000 - fb60: 00000000 00000000 00002010 ffffff80 60000145 00000000 00000000 00000000 - fb80: 0000011a 00000000 0000001d 00000000 0079e000 ffffffc0 c044c000 ffffffc3 - fba0: 0000000a 00000000 0016cac2 00000001 00570c08 ffffffc0 084040c0 0000000a - fbc0: c044fbe0 ffffffc3 000ecb2c ffffffc0 00780000 ffffffc0 000ecafc ffffffc0 - fbe0: c044fc20 ffffffc3 00082420 ffffffc0 00797000 ffffffc0 c044fc50 ffffffc3 - fc00: 0000200c ffffff80 000fc014 ffffffc0 ee010000 ffffffc3 000a253c 0000005c - fc20: c044fd70 ffffffc3 00085da8 ffffffc0 00000000 00000000 fd024c90 ffffffc0 - fc40: c044fd70 ffffffc3 000d0938 ffffffc0 fd024c98 ffffffc0 ee3aee00 ffffffc3 - fc60: 00000000 00000000 00000000 00000000 0000ae80 00000000 00000000 00000000 - fc80: 00000000 00000000 c7e8ed00 5df42439 0000001d 00000000 00920000 00000000 - fca0: ffffffff 00000000 0000001b 00000000 00000000 00000000 00920000 00000000 - fcc0: 00000000 00000000 84b805a0 0000007f 001a6a8c ffffffc0 84afbc90 0000007f - fce0: 82d1c1f0 0000007f 00000000 00000000 fd024c90 ffffffc0 00000000 00000000 - fd00: feabe300 ffffffc0 0000ae80 00000000 00000000 00000000 0000011a 00000000 - fd20: 0000001d 00000000 0079e000 ffffffc0 c044c000 ffffffc3 c044fd70 ffffffc3 - fd40: 0009c1d0 ffffffc0 c044fd70 ffffffc3 000d0938 ffffffc0 60000145 00000000 - fd60: c044fd70 ffffffc3 0009c1a4 ffffffc0 c044fda0 ffffffc3 0009c2e0 ffffffc0 - fd80: feabe300 ffffffc0 fd024c90 ffffffc0 0079e000 ffffffc0 c044c000 00000000 - fda0: c044fe10 ffffffc3 001a6824 ffffffc0 feabe300 ffffffc0 00000000 00000000 - fdc0: edc06f70 ffffffc3 0000000b 00000000 0000ae80 00000000 00000015 00000000 - fde0: 0000011a 00000000 00000040 0000ae80 c044fe20 ffffffc3 0019772c ffffffc0 - fe00: edb30000 ffffffc3 00000001 00000000 c044fe90 ffffffc3 001a6b10 ffffffc0 - fe20: 00000000 00000000 feabe301 ffffffc0 feabe300 ffffffc0 00000000 00000000 - fe40: c044fe70 ffffffc3 001b0a2c ffffffc0 00000000 00000000 ed3ea300 ffffffc3 - fe60: c044fe80 0000000b feabe300 ffffffc0 c044fe80 ffffffc3 001b0a80 ffffffc0 - fe80: c044fe90 ffffffc3 001a6acc ffffffc0 82d1c600 0000007f 00086430 ffffffc0 - fea0: 00000000 00000000 15b1cea0 00000000 ffffffff ffffffff 84afbc9c 0000007f - fec0: 60000000 00000000 00000015 00000000 0000000b 00000000 0000ae80 00000000 - fee0: 00000000 00000000 ffffff80 00000000 82d1c700 0000007f 00000001 00000000 - ff00: 00000000 00000000 c7e8ed00 5df42439 0000001d 00000000 00920000 00000000 - ff20: ffffffff 00000000 0000001b 00000000 00000000 00000000 00920000 00000000 - ff40: 00000000 00000000 84b805a0 0000007f 008bc3d0 00000000 84afbc90 0000007f - ff60: 82d1c1f0 0000007f 00920000 00000000 15b1cea0 00000000 00000000 00000000 - ff80: 00000001 00000000 84baa000 0000007f 82d1d090 0000007f 15b2512c 00000000 - ffa0: 837076f0 0000007f 00800000 00000000 84baf000 0000007f 82d1c600 0000007f - ffc0: 004545a0 00000000 82d1c600 0000007f 84afbc9c 0000007f 60000000 00000000 - ffe0: 0000000b 00000000 0000001d 00000000 00000000 00000000 00000000 00000000 - Call trace: - [<ffffffc0003f9058>] xgene_enet_process_ring+0x94/0x328 - [<ffffffc0003f93cc>] xgene_enet_napi+0x1c/0x54 - [<ffffffc0004a5ce8>] net_rx_action+0x1dc/0x2b8 - [<ffffffc0000b5d9c>] __do_softirq+0x100/0x220 - [<ffffffc0000b6130>] irq_exit+0x90/0xd0 - [<ffffffc0000ecb28>] __handle_domain_irq+0x60/0xac - [<ffffffc00008241c>] gic_handle_irq+0x30/0x80 - Exception stack(0xffffffc3c044fc30 to 0xffffffc3c044fd50) - fc20: 00000000 00000000 fd024c90 ffffffc0 - fc40: c044fd70 ffffffc3 000d0938 ffffffc0 fd024c98 ffffffc0 ee3aee00 ffffffc3 - fc60: 00000000 00000000 00000000 00000000 0000ae80 00000000 00000000 00000000 - fc80: 00000000 00000000 c7e8ed00 5df42439 0000001d 00000000 00920000 00000000 - fca0: ffffffff 00000000 0000001b 00000000 00000000 00000000 00920000 00000000 - fcc0: 00000000 00000000 84b805a0 0000007f 001a6a8c ffffffc0 84afbc90 0000007f - fce0: 82d1c1f0 0000007f 00000000 00000000 fd024c90 ffffffc0 00000000 00000000 - fd00: feabe300 ffffffc0 0000ae80 00000000 00000000 00000000 0000011a 00000000 - fd20: 0000001d 00000000 0079e000 ffffffc0 c044c000 ffffffc3 c044fd70 ffffffc3 - fd40: 0009c1d0 ffffffc0 c044fd70 ffffffc3 - [<ffffffc000085da4>] el1_irq+0x64/0xd8 - [<ffffffc00009c2dc>] kvm_vcpu_ioctl+0x54/0x6f8 - [<ffffffc0001a6820>] do_vfs_ioctl+0x378/0x5e4 - [<ffffffc0001a6b0c>] SyS_ioctl+0x80/0x98 - Code: f1000b5f f863581b 54001348 79401e82 (f9406360) - ---[ end trace 65548354a1e73544 ]--- - Kernel panic - not syncing: Fatal exception in interrupt - CPU6: stopping - CPU: 6 PID: 0 Comm: swapper/6 Tainted: G D 3.19.0-rc7+ #254 - Hardware name: APM X-Gene Mustang board (DT) - Call trace: - [<ffffffc00008a01c>] dump_backtrace+0x0/0x124 - [<ffffffc00008a150>] show_stack+0x10/0x1c - [<ffffffc00055f350>] dump_stack+0x80/0xc4 - [<ffffffc000092e74>] handle_IPI+0x184/0x194 - [<ffffffc000082464>] gic_handle_irq+0x78/0x80 - Exception stack(0xffffffc3ee16be40 to 0xffffffc3ee16bf60) - be40: ee168000 ffffffc3 007945d0 ffffffc0 ee16bf80 ffffffc3 00087108 ffffffc0 - be60: 00000000 00000000 00000000 00000000 fffa1b1c ffffffc3 fffa1b1c ffffffc3 - be80: 00000020 00000000 0ccccccd 00000000 a7ea326e 002208f8 fffa1c88 ffffffc3 - bea0: ee14bc40 ffffffc3 ee16bd90 ffffffc3 54df86d6 00000000 0008d1b1 00000000 - bec0: 00000018 00000000 e8000000 00000003 00000000 00000000 37ea326e 0022731c - bee0: 0010e164 ffffffc0 a9b20c84 0000007f dc507870 0000007f ee168000 ffffffc3 - bf00: 007945d0 ffffffc0 00794654 ffffffc0 00570920 ffffffc0 007e3beb ffffffc0 - bf20: 006b1598 ffffffc0 00816000 00000040 00818000 00000040 000826e0 ffffffc0 - bf40: 00000000 00000080 ee16bf80 ffffffc3 00087104 ffffffc0 ee16bf80 ffffffc3 - [<ffffffc000085da4>] el1_irq+0x64/0xd8 - [<ffffffc0000e3df4>] cpu_startup_entry+0xdc/0x12c - [<ffffffc000092944>] secondary_start_kernel+0x114/0x124 - CPU2: stopping - CPU: 2 PID: 0 Comm: swapper/2 Tainted: G D 3.19.0-rc7+ #254 - Hardware name: APM X-Gene Mustang board (DT) - Call trace: - [<ffffffc00008a01c>] dump_backtrace+0x0/0x124 - [<ffffffc00008a150>] show_stack+0x10/0x1c - [<ffffffc00055f350>] dump_stack+0x80/0xc4 - [<ffffffc000092e74>] handle_IPI+0x184/0x194 - [<ffffffc000082464>] gic_handle_irq+0x78/0x80 - Exception stack(0xffffffc3ee153e40 to 0xffffffc3ee153f60) - 3e40: ee150000 ffffffc3 007945d0 ffffffc0 ee153f80 ffffffc3 00087108 ffffffc0 - 3e60: 00000000 00000000 00000000 00000000 fff6db1c ffffffc3 00000001 00000000 - 3e80: 00000008 00000000 00000010 00000000 fff6e060 ffffffc3 fff6dc88 ffffffc3 - 3ea0: ee149040 ffffffc3 ee153d90 ffffffc3 000003ff 00000000 b5193519 00000033 - 3ec0: 56000000 00000000 00000000 00000000 00000000 00000000 98334438 0000007f - 3ee0: 440c0400 000000ff 00085000 ffffffc0 00000000 00000000 ee150000 ffffffc3 - 3f00: 007945d0 ffffffc0 00794654 ffffffc0 00570920 ffffffc0 007e3beb ffffffc0 - 3f20: 006b1598 ffffffc0 00816000 00000040 00818000 00000040 000826e0 ffffffc0 - 3f40: 00000000 00000080 ee153f80 ffffffc3 00087104 ffffffc0 ee153f80 ffffffc3 - [<ffffffc000085da4>] el1_irq+0x64/0xd8 - [<ffffffc0000e3df4>] cpu_startup_entry+0xdc/0x12c - [<ffffffc000092944>] secondary_start_kernel+0x114/0x124 - CPU4: stopping - CPU: 4 PID: 0 Comm: swapper/4 Tainted: G D 3.19.0-rc7+ #254 - Hardware name: APM X-Gene Mustang board (DT) - Call trace: - [<ffffffc00008a01c>] dump_backtrace+0x0/0x124 - [<ffffffc00008a150>] show_stack+0x10/0x1c - [<ffffffc00055f350>] dump_stack+0x80/0xc4 - [<ffffffc000092e74>] handle_IPI+0x184/0x194 - [<ffffffc000082464>] gic_handle_irq+0x78/0x80 - Exception stack(0xffffffc3ee15be40 to 0xffffffc3ee15bf60) - be40: ee158000 ffffffc3 007945d0 ffffffc0 ee15bf80 ffffffc3 00087108 ffffffc0 - be60: 00000000 00000000 00000000 00000000 fff87b1c ffffffc3 0046dda0 ffffffc0 - be80: 00000020 00000000 0ccccccd 00000000 a7ea326e 00364cf5 fff87c88 ffffffc3 - bea0: ee14a640 ffffffc3 ee15bd90 ffffffc3 000003ff 00000000 b5193519 00000033 - bec0: 56000000 00000000 00000000 00000000 00000000 00000000 0071eac8 00000000 - bee0: 440c0400 000000ff 00085000 ffffffc0 00000000 00000000 ee158000 ffffffc3 - bf00: 007945d0 ffffffc0 00794654 ffffffc0 00570920 ffffffc0 007e3beb ffffffc0 - bf20: 006b1598 ffffffc0 00816000 00000040 00818000 00000040 000826e0 ffffffc0 - bf40: 00000000 00000080 ee15bf80 ffffffc3 00087104 ffffffc0 ee15bf80 ffffffc3 - [<ffffffc000085da4>] el1_irq+0x64/0xd8 - [<ffffffc0000e3df4>] cpu_startup_entry+0xdc/0x12c - [<ffffffc000092944>] secondary_start_kernel+0x114/0x124 - CPU5: stopping - CPU: 5 PID: 0 Comm: swapper/5 Tainted: G D 3.19.0-rc7+ #254 - Hardware name: APM X-Gene Mustang board (DT) - Call trace: - [<ffffffc00008a01c>] dump_backtrace+0x0/0x124 - [<ffffffc00008a150>] show_stack+0x10/0x1c - [<ffffffc00055f350>] dump_stack+0x80/0xc4 - [<ffffffc000092e74>] handle_IPI+0x184/0x194 - [<ffffffc000082464>] gic_handle_irq+0x78/0x80 - Exception stack(0xffffffc3ee15fe40 to 0xffffffc3ee15ff60) - fe40: ee15c000 ffffffc3 007945d0 ffffffc0 ee15ff80 ffffffc3 00087108 ffffffc0 - fe60: 00000000 00000000 00000000 00000000 fff94b1c ffffffc3 0046dda0 ffffffc0 - fe80: 00000020 00000000 0ccccccd 00000000 a7ea326e 00364cf5 fff94c88 ffffffc3 - fea0: ee14b140 ffffffc3 ee15fd90 ffffffc3 000003ff 00000000 b5193519 00000033 - fec0: 56000000 00000000 00000000 00000000 00000000 00000000 a4f652e0 0000007f - fee0: 440c0400 000000ff 00085000 ffffffc0 00000000 00000000 ee15c000 ffffffc3 - ff00: 007945d0 ffffffc0 00794654 ffffffc0 00570920 ffffffc0 007e3beb ffffffc0 - ff20: 006b1598 ffffffc0 00816000 00000040 00818000 00000040 000826e0 ffffffc0 - ff40: 00000000 00000080 ee15ff80 ffffffc3 00087104 ffffffc0 ee15ff80 ffffffc3 - [<ffffffc000085da4>] el1_irq+0x64/0xd8 - [<ffffffc0000e3df4>] cpu_startup_entry+0xdc/0x12c - [<ffffffc000092944>] secondary_start_kernel+0x114/0x124 - CPU1: stopping - CPU: 1 PID: 0 Comm: swapper/1 Tainted: G D 3.19.0-rc7+ #254 - Hardware name: APM X-Gene Mustang board (DT) - Call trace: - [<ffffffc00008a01c>] dump_backtrace+0x0/0x124 - [<ffffffc00008a150>] show_stack+0x10/0x1c - [<ffffffc00055f350>] dump_stack+0x80/0xc4 - [<ffffffc000092e74>] handle_IPI+0x184/0x194 - [<ffffffc000082464>] gic_handle_irq+0x78/0x80 - Exception stack(0xffffffc3ee147e40 to 0xffffffc3ee147f60) - 7e40: ee144000 ffffffc3 007945d0 ffffffc0 ee147f80 ffffffc3 00087108 ffffffc0 - 7e60: 00000000 00000000 00000000 00000000 fff60b1c ffffffc3 007a7840 ffffffc0 - 7e80: ee147f00 ffffffc3 ff7e1000 00000003 27ea326e 003816b9 fff62798 ffffffc3 - 7ea0: ee148540 ffffffc3 ee147d90 ffffffc3 54df86d6 00000000 000e84ba 00000000 - 7ec0: 00000018 00000000 e8000000 00000003 00000000 00000000 97ea326e 0038b676 - 7ee0: 0010e164 ffffffc0 86528280 0000007f 8525d920 0000007f ee144000 ffffffc3 - 7f00: 007945d0 ffffffc0 00794654 ffffffc0 00570920 ffffffc0 007e3beb ffffffc0 - 7f20: 006b1598 ffffffc0 00816000 00000040 00818000 00000040 000826e0 ffffffc0 - 7f40: 00000000 00000080 ee147f80 ffffffc3 00087104 ffffffc0 ee147f80 ffffffc3 - [<ffffffc000085da4>] el1_irq+0x64/0xd8 - [<ffffffc0000e3df4>] cpu_startup_entry+0xdc/0x12c - [<ffffffc000092944>] secondary_start_kernel+0x114/0x124 - CPU7: stopping - CPU: 7 PID: 0 Comm: swapper/7 Tainted: G D 3.19.0-rc7+ #254 - Hardware name: APM X-Gene Mustang board (DT) - Call trace: - [<ffffffc00008a01c>] dump_backtrace+0x0/0x124 - [<ffffffc00008a150>] show_stack+0x10/0x1c - [<ffffffc00055f350>] dump_stack+0x80/0xc4 - [<ffffffc000092e74>] handle_IPI+0x184/0x194 - [<ffffffc000082464>] gic_handle_irq+0x78/0x80 - Exception stack(0xffffffc3ee16fe40 to 0xffffffc3ee16ff60) - fe40: ee16c000 ffffffc3 007945d0 ffffffc0 ee16ff80 ffffffc3 00087108 ffffffc0 - fe60: 00000000 00000000 00000000 00000000 fffaeb1c ffffffc3 0046dda0 ffffffc0 - fe80: 00000020 00000000 0ccccccd 00000000 27ea326e 003816b9 fffaec88 ffffffc3 - fea0: ee14c740 ffffffc3 ee16fd90 ffffffc3 000003ff 00000000 00000005 00000000 - fec0: 005715fc ffffffc0 00000012 00000000 006ce888 ffffffc0 00000000 00000000 - fee0: 00000220 00000000 008bc420 00000000 87ffe440 0000007d ee16c000 ffffffc3 - ff00: 007945d0 ffffffc0 00794654 ffffffc0 00570920 ffffffc0 007e3beb ffffffc0 - ff20: 006b1598 ffffffc0 00816000 00000040 00818000 00000040 000826e0 ffffffc0 - ff40: 00000000 00000080 ee16ff80 ffffffc3 00087104 ffffffc0 ee16ff80 ffffffc3 - [<ffffffc000085da4>] el1_irq+0x64/0xd8 - [<ffffffc0000e3df4>] cpu_startup_entry+0xdc/0x12c - [<ffffffc000092944>] secondary_start_kernel+0x114/0x124 - CPU3: stopping - CPU: 3 PID: 0 Comm: swapper/3 Tainted: G D 3.19.0-rc7+ #254 - Hardware name: APM X-Gene Mustang board (DT) - Call trace: - [<ffffffc00008a01c>] dump_backtrace+0x0/0x124 - [<ffffffc00008a150>] show_stack+0x10/0x1c - [<ffffffc00055f350>] dump_stack+0x80/0xc4 - [<ffffffc000092e74>] handle_IPI+0x184/0x194 - [<ffffffc000082464>] gic_handle_irq+0x78/0x80 - Exception stack(0xffffffc3ee157e40 to 0xffffffc3ee157f60) - 7e40: ee154000 ffffffc3 007945d0 ffffffc0 ee157f80 ffffffc3 00087108 ffffffc0 - 7e60: 00000000 00000000 00000000 00000000 fff7ab1c ffffffc3 0046dda0 ffffffc0 - 7e80: 00000020 00000000 0ccccccd 00000000 27ea326e 001584a0 fff7ac88 ffffffc3 - 7ea0: ee1dd038 ffffffc3 0000000b 00000000 00000000 00000000 00000040 00000000 - 7ec0: 00000018 00000000 ab20b4ae ffffffff 84000000 002429ba 00000000 003b9aca - 7ee0: 001a8064 ffffffc0 ac9bc410 0000007f f9cdda11 00000000 ee154000 ffffffc3 - 7f00: 007945d0 ffffffc0 00794654 ffffffc0 00570920 ffffffc0 007e3beb ffffffc0 - 7f20: 006b1598 ffffffc0 00816000 00000040 00818000 00000040 000826e0 ffffffc0 - 7f40: 00000000 00000080 ee157f80 ffffffc3 00087104 ffffffc0 ee157f80 ffffffc3 - [<ffffffc000085da4>] el1_irq+0x64/0xd8 - [<ffffffc0000e3df4>] cpu_startup_entry+0xdc/0x12c - [<ffffffc000092944>] secondary_start_kernel+0x114/0x124 - ---[ end Kernel panic - not syncing: Fatal exception in interrupt + On failure, you'll get a panic within several hours. + + [Regression Risk] + The proposed patch only touches the impacted driver. It is adding a memory barrier - albeit a lightweight one - so there is the risk of a performance degradation. Indeed, when measured using a 60s iperf run, I do see a performance drop, but by < 0.5%.
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1425576 Title: Occasional crash in APM xgene enet driver on kernels prior to v3.19 Status in linux package in Ubuntu: Triaged Status in linux source package in Trusty: In Progress Status in linux source package in Utopic: In Progress Bug description: [Impact] System panics every few hours under constant network load [Test Case] On the X-Gene system, start an iperf server: $ iperf -s Connect to it from another system (1Gbps is sufficient) $ iperf -t 100000 -c <xgene host> On failure, you'll get a panic within several hours. [Regression Risk] The proposed patch only touches the impacted driver. It is adding a memory barrier - albeit a lightweight one - so there is the risk of a performance degradation. Indeed, when measured using a 60s iperf run, I do see a performance drop, but by < 0.5%. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1425576/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
