| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <1271402283.16881.3791.camel@edumazet-laptop> Date: Fri, 16 Apr 2010 09:18:03 +0200 From: Eric Dumazet <eric.dumazet@...il.com> To: David Miller <davem@...emloft.net> Cc: therbert@...gle.com, netdev@...r.kernel.org Subject: Re: [PATCH v5] rfs: Receive Flow Steering Le vendredi 16 avril 2010 à 08:56 +0200, Eric Dumazet a écrit : > I read the patch and found no error. > > I booted a test machine and performed some tests > > I am a bit worried of a tbench regression I am looking at right now. > > if RFS disabled , tbench 16 -> 4408.63 MB/sec > > > # grep . /sys/class/net/lo/queues/rx-0/* > /sys/class/net/lo/queues/rx-0/rps_cpus:00000000 > /sys/class/net/lo/queues/rx-0/rps_flow_cnt:8192 > # cat /proc/sys/net/core/rps_sock_flow_entries > 8192 > > > echo ffff >/sys/class/net/lo/queues/rx-0/rps_cpus > > tbench 16 -> 2336.32 MB/sec > > > ----------------------------------------------------------------------------------------------------------------------------------------------------- > PerfTop: 14561 irqs/sec kernel:86.3% [1000Hz cycles], (all, 16 CPUs) > ----------------------------------------------------------------------------------------------------------------------------------------------------- > > samples pcnt function DSO > _______ _____ ______________________________ __________________________________________________________ > > 2664.00 5.1% copy_user_generic_string /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 2323.00 4.4% acpi_os_read_port /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 1641.00 3.1% _raw_spin_lock_irqsave /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 1260.00 2.4% schedule /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 1159.00 2.2% _raw_spin_lock /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 1051.00 2.0% tcp_ack /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 991.00 1.9% tcp_sendmsg /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 922.00 1.8% tcp_recvmsg /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 821.00 1.6% child_run /usr/bin/tbench > 766.00 1.5% all_string_sub /usr/bin/tbench > 630.00 1.2% __switch_to /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 608.00 1.2% __GI_strchr /lib/tls/libc-2.3.4.so > 606.00 1.2% ipt_do_table /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 600.00 1.1% __GI_strstr /lib/tls/libc-2.3.4.so > 556.00 1.1% __netif_receive_skb /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 504.00 1.0% tcp_transmit_skb /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 502.00 1.0% tick_nohz_stop_sched_tick /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 481.00 0.9% _raw_spin_unlock_irqrestore /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 473.00 0.9% next_token /usr/bin/tbench > 449.00 0.9% ip_rcv /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 423.00 0.8% call_function_single_interrupt /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 422.00 0.8% ia32_sysenter_target /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 420.00 0.8% compat_sys_socketcall /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 401.00 0.8% mod_timer /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 400.00 0.8% process_backlog /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 399.00 0.8% ip_queue_xmit /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 387.00 0.7% select_task_rq_fair /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 377.00 0.7% _raw_spin_lock_bh /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > 360.00 0.7% tcp_v4_rcv /lib/modules/2.6.34-rc3-03375-ga4fbf84-dirty/build/vmlinux > > But if RFS is on, why activating rps_cpus change tbench ? > Hmm, I wonder if its not an artifact of net-next-2.6 being a bit old (versus linux-2.6). I know scheduler guys did some tweaks. Because apparently, some cpus are idle part of their time (30% ???) Or a new bug on cpu accounting, reporting idle time while cpus are busy.... # vmstat 1 procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 16 0 0 5670264 13280 63392 0 0 2 1 1512 227 12 47 41 0 18 0 0 5669396 13280 63392 0 0 0 0 657952 1606102 14 58 28 0 17 0 0 5668776 13288 63392 0 0 0 12 656701 1606369 14 58 28 0 18 0 0 5669644 13288 63392 0 0 0 0 657636 1603960 15 57 28 0 17 0 0 5670900 13288 63392 0 0 0 0 666425 1584847 15 56 29 0 15 0 0 5669164 13288 63392 0 0 0 0 682578 1472616 14 56 30 0 16 0 0 5669412 13288 63392 0 0 0 0 695767 1506302 14 54 32 0 14 0 0 5668916 13296 63396 0 0 4 148 685286 1482897 14 56 30 0 17 0 0 5669784 13296 63396 0 0 0 0 683910 1477994 14 56 30 0 18 0 0 5670032 13296 63396 0 0 0 0 692023 1497195 14 55 31 0 16 0 0 5669040 13296 63396 0 0 0 0 677477 1468157 14 56 30 0 16 0 0 5668916 13312 63396 0 0 0 32 489358 1048553 14 57 30 0 18 0 0 5667924 13320 63396 0 0 0 12 424787 897145 15 55 29 0 RFS off : # vmstat 1 procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 24 0 0 5669624 13632 63476 0 0 2 1 261 82 12 48 40 0 26 0 0 5669492 13632 63476 0 0 0 0 4223 1740651 21 71 7 0 23 0 0 5669864 13640 63476 0 0 0 12 4205 1731882 21 71 8 0 23 0 0 5670484 13640 63476 0 0 0 0 4176 1733448 21 71 8 0 24 0 0 5670588 13640 63476 0 0 0 0 4176 1733845 21 72 7 0 21 0 0 5671084 13640 63476 0 0 0 0 4200 1734990 20 73 7 0 23 0 0 5671580 13640 63476 0 0 0 0 4168 1735100 21 71 8 0 23 0 0 5671704 13640 63480 0 0 4 132 4221 1733428 21 72 7 0 22 0 0 5671952 13640 63480 0 0 0 0 4190 1730370 21 72 8 0 20 0 0 5672292 13640 63480 0 0 0 0 4212 1732084 22 70 8 0 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists