On Mon, 2008-11-17 at 11:39 -0800, David Miller wrote: > From: Ingo Molnar <mingo@xxxxxxx> > Date: Mon, 17 Nov 2008 19:49:51 +0100 > > > > > * Ingo Molnar <mingo@xxxxxxx> wrote: > > > > 4> The place for the sock_rfree() hit looks a bit weird, and i'll > > > investigate it now a bit more to place the real overhead point > > > properly. (i already mapped the test-bit overhead: that comes from > > > napi_disable_pending()) > > > > ok, here's a new set of profiles. (again for tbench 64-thread on a > > 16-way box, with v2.6.28-rc5-19-ge14c8bf and with the kernel config i > > posted before.) > > Again, do a non-NMI profile and the top (at least for me) > looks like this: > > samples % app name symbol name > 473 6.3928 vmlinux finish_task_switch > 349 4.7169 vmlinux tcp_v4_rcv > 327 4.4195 vmlinux U3copy_from_user > 322 4.3519 vmlinux tl0_linux32 > 178 2.4057 vmlinux tcp_ack > 170 2.2976 vmlinux tcp_sendmsg > 167 2.2571 vmlinux U3copy_to_user > > That tcp_v4_rcv() hit is %98 on the wake_up() call it does. Easy enough, since i don't know how to do spiffy NMI profile.. yet ;-) I revived the 2.6.25 kernel where I tested back-ports of recent sched fixes, and did a non-NMI profile of 2.6.22.19 and the back-port kernel. The test kernel has all clock fixes 25->.git, min_vruntime accuracy fix native_read_tsc() fix, and back looking buddy. No knobs turned, and only testing one pair per CPU, as to not take unfair advantage of back looking buddy. Netperf TCP_RR (hits sched harder) looks about the same. Tbench 4 throughput was so close you would call these two twins. 2.6.22.19-smp CPU: Core 2, speed 2400 MHz (estimated) Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit mask of 0x00 (Unhalted core cycles) count 100000 vma samples % symbol name ffffffff802e6670 575909 13.7425 copy_user_generic_string ffffffff80422ad8 175649 4.1914 schedule ffffffff803a522d 133152 3.1773 tcp_sendmsg ffffffff803a9387 128911 3.0761 tcp_ack ffffffff803b65f7 116562 2.7814 tcp_v4_rcv ffffffff803aeac8 116541 2.7809 tcp_transmit_skb ffffffff8039eb95 112133 2.6757 ip_queue_xmit ffffffff80209e20 110945 2.6474 system_call ffffffff8037b720 108277 2.5837 __kfree_skb ffffffff803a65cd 105493 2.5173 tcp_recvmsg ffffffff80210f87 97947 2.3372 read_tsc ffffffff802085b6 95255 2.2730 __switch_to ffffffff803803f1 82069 1.9584 netif_rx ffffffff8039f645 80937 1.9313 ip_output ffffffff8027617d 74585 1.7798 __slab_alloc ffffffff803824a0 70928 1.6925 process_backlog ffffffff803ad9a5 69574 1.6602 tcp_rcv_established ffffffff80399d40 55453 1.3232 ip_rcv ffffffff803b07d1 53256 1.2708 __tcp_push_pending_frames ffffffff8037b49c 52565 1.2543 skb_clone ffffffff80276e97 49690 1.1857 __kmalloc_track_caller ffffffff80379d05 45450 1.0845 sock_wfree ffffffff80223d82 44851 1.0702 effective_prio ffffffff803826b6 42417 1.0122 net_rx_action ffffffff8027684c 42341 1.0104 kfree 2.6.25.20-test-smp CPU: Core 2, speed 2400 MHz (estimated) Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit mask of 0x00 (Unhalted core cycles) count 100000 vma samples % symbol name ffffffff80301450 576125 14.0874 copy_user_generic_string ffffffff803cf8d9 127997 3.1298 tcp_transmit_skb ffffffff803c9eac 125402 3.0663 tcp_ack ffffffff80454da3 122337 2.9914 schedule ffffffff803c673c 120401 2.9440 tcp_sendmsg ffffffff8039aa9e 116554 2.8500 skb_release_all ffffffff803c5abb 104840 2.5635 tcp_recvmsg ffffffff8020a63d 92180 2.2540 __switch_to ffffffff8020be20 79703 1.9489 system_call ffffffff803bf460 79384 1.9411 ip_queue_xmit ffffffff803a005c 78035 1.9081 netif_rx ffffffff803ce56b 71223 1.7415 tcp_rcv_established ffffffff8039ff70 66493 1.6259 process_backlog ffffffff803d5a2d 61635 1.5071 tcp_v4_rcv ffffffff803c1dae 60889 1.4889 __inet_lookup_established ffffffff802126bc 54711 1.3378 native_read_tsc ffffffff803d23bc 51843 1.2677 __tcp_push_pending_frames ffffffff803bfb24 51821 1.2671 ip_finish_output ffffffff8023700c 48248 1.1798 local_bh_enable ffffffff803979bc 42221 1.0324 sock_wfree ffffffff8039b12c 41279 1.0094 __alloc_skb -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
