Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752021AbXI3SqQ (ORCPT ); Sun, 30 Sep 2007 14:46:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750887AbXI3SqC (ORCPT ); Sun, 30 Sep 2007 14:46:02 -0400 Received: from usermail.globalproof.net ([194.146.153.18]:36683 "EHLO usermail.globalproof.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750846AbXI3SqA (ORCPT ); Sun, 30 Sep 2007 14:46:00 -0400 From: "Denys" To: linux-kernel@vger.kernel.org Subject: Re: 2.6.21 -> 2.6.22 & 2.6.23-rc8 performance regression Date: Sun, 30 Sep 2007 21:45:47 +0300 Message-Id: <20070930184547.M90508@nuclearcat.com> In-Reply-To: <46FFE17C.9020202@cosmosbay.com> References: <20070930144443.M52139@visp.net.lb> <46FFE17C.9020202@cosmosbay.com> X-Mailer: OpenWebMail 2.52 20060502 X-OriginatingIP: 195.69.208.251 (denys@visp.net.lb) MIME-Version: 1.0 Content-Type: text/plain; charset=koi8-r Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5664 Lines: 158 Hi pi ~ # zcat /proc/config.gz |grep SLUB # CONFIG_SLUB_DEBUG is not set CONFIG_SLUB=y 21:27:20 CPU %user %nice %sys %iowait %irq %soft %steal %idle intr/s 21:27:21 all 5.53 21.61 8.54 0.00 0.50 5.03 0.00 58.79 7147.52 21:27:22 all 6.40 15.76 8.87 0.00 0.49 20.20 0.00 48.28 6327.00 21:27:23 all 6.53 20.60 12.06 0.00 0.00 52.76 0.00 8.04 456.44 21:27:24 all 7.00 17.50 10.50 0.00 0.00 53.00 0.00 12.00 439.00 21:27:25 all 7.50 18.00 12.50 0.50 0.50 52.50 0.00 8.50 464.00 21:27:26 all 6.64 16.11 11.37 0.00 0.00 58.77 0.00 7.11 401.90 21:27:27 all 0.00 0.40 0.40 0.00 0.00 99.20 0.00 0.00 325.20 21:27:28 all 0.00 0.50 0.00 0.00 0.00 99.50 0.00 0.00 453.47 21:27:29 all 0.00 0.00 0.00 0.00 0.00 100.00 0.00 0.00 495.10 21:27:30 all 0.00 0.50 0.00 0.00 0.00 99.50 0.00 0.00 625.74 21:27:31 all 0.00 0.00 0.00 0.00 0.00 100.00 0.00 0.00 600.97 21:27:32 all 0.00 0.00 0.00 0.00 0.00 100.00 0.00 0.00 604.95 64 bytes from 127.0.0.1: icmp_seq=15 ttl=64 time=0.031 ms 64 bytes from 127.0.0.1: icmp_seq=16 ttl=64 time=229 ms 64 bytes from 127.0.0.1: icmp_seq=17 ttl=64 time=253 ms 64 bytes from 127.0.0.1: icmp_seq=18 ttl=64 time=257 ms 64 bytes from 127.0.0.1: icmp_seq=19 ttl=64 time=279 ms 64 bytes from 127.0.0.1: icmp_seq=20 ttl=64 time=246 ms 64 bytes from 127.0.0.1: icmp_seq=21 ttl=64 time=246 ms 64 bytes from 127.0.0.1: icmp_seq=22 ttl=64 time=234 ms 64 bytes from 127.0.0.1: icmp_seq=23 ttl=64 time=235 ms Problem remains. It is another server. On Sun, 30 Sep 2007 19:48:44 +0200, Eric Dumazet wrote > > I've moved recently one of my proxies(squid and some compressing application) > > from 2.6.21 to 2.6.22, and notice huge performance drop. I think this is > > important, cause it can cause serious regression on some other workloads like > > busy web-servers and etc. > > > > After some analysis of different options i can bring more exact numbers: > > > > 2.6.21 able to process 500-550 requests/second and 15-20 Mbit/s of traffic, > > and working great without any slowdown or instability. > > > > 2.6.22 able to process only 250-300 requests and 8-10 Mbit/s of traffic, ssh > > and console is "freezing" (there is delay even for typing characters). > > > > Both proxies is on identical hardware(Sun Fire X4100), configuration(small > > system, LFS-like, on USB flash), different only kernel. > > > > I tried to disable/enable various options and optimisations - it doesn't > > change anything, till i reach SLUB/SLAB option. > > > > I've loaded proxy configuration to gentoo PC with 2.6.22 (then upgraded it to > > 2.6.23-rc8), and having same effect. > > Additionally, when load reaching maximum i can notice whole system slowdown, > > for example ssh and scp takes much more time to run, even i do nice -n -5 for > > them. > > > > But even choosing 2.6.23-rc8+SLAB i noticed same "freezing" of ssh (and sure > > it slowdown other kind of network performance), but much less comparing with > > SLUB. On top i am seeing ksoftirqd taking almost 100% (sometimes ksoftirqd/0, > > sometimes ksoftirqd/1). > > > > I tried also different tricks with scheduler (/proc/sys/kernel/sched*), but > > it's also didn't help. > > > > When it freezes it looks like: > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > > 7 root 15 -5 0 0 0 R 64 0.0 2:47.48 ksoftirqd/1 > > 5819 root 20 0 134m 130m 596 R 57 3.3 4:36.78 globax > > 5911 squid 20 0 1138m 1.1g 2124 R 26 28.9 2:24.87 squid > > 10 root 15 -5 0 0 0 S 1 0.0 0:01.86 events/1 > > 6130 root 20 0 3960 2416 1592 S 0 0.1 0:08.02 oprofiled > > > > > > Oprofile results: > > > > > > Thats oprofile with 2.6.23-rc8 - SLUB > > > > 73918 21.5521 check_bytes > > 38361 11.1848 acpi_pm_read > > 14077 4.1044 init_object > > 13632 3.9747 ip_send_reply > > 8486 2.4742 __slab_alloc > > 7199 2.0990 nf_iterate > > 6718 1.9588 page_address > > 6716 1.9582 tcp_v4_rcv > > 6425 1.8733 __slab_free > > 5604 1.6339 on_freelist > > > > > > Thats oprofile with 2.6.23-rc8 - SLAB > > > > CPU: AMD64 processors, speed 2592.64 MHz (estimated) > > Counted CPU_CLK_UNHALTED events (Cycles outside of halt state) with a unit > > mask of 0x00 (No unit mask) count 100000 > > samples % symbol name > > 138991 14.0627 acpi_pm_read > > 52401 5.3018 tcp_v4_rcv > > 48466 4.9037 nf_iterate > > 38043 3.8491 __slab_alloc > > 34155 3.4557 ip_send_reply > > 20963 2.1210 ip_rcv > > 19475 1.9704 csum_partial > > 19084 1.9309 kfree > > 17434 1.7639 ip_output > > 17278 1.7481 netif_receive_skb > > 15248 1.5428 nf_hook_slow > > > > My .config is at http://www.nuclearcat.com/.config (there is SPARSEMEM > > enabled, it doesn't make any noticeable difference) > > > > Please CC me on reply, i am not in list. > > > > Could you try with SLUB but disabling CONFIG_SLUB_DEBUG ? -- Denys Fedoryshchenko Technical Manager Virtual ISP S.A.L. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/