lkml.org 
[lkml]   [2002]   [Jun]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [Lse-tech] Re: [RFC] Dynamic percpu data allocator
From
Date

For whatever it is worth, here are the functions ranked in
decreasing order of savings due to the IRQ and process
affinity. Column 2 is profile ticks with affinity, column 3
is without, and column 4 is the difference.

Thanx, Paul

poll_idle 72241 121743 49502
schedule 9036 24853 15817
csum_partial_copy_generic 13838 27951 14113
tcp_v4_rcv 629 6449 5820
mod_timer 1551 6997 5446
do_softirq 3922 9130 5208
__wake_up 1779 6143 4364
speedo_rx 0 3358 3358
tcp_recvmsg 2154 5199 3045
tcp_data_wait 748 3610 2862
handle_IRQ_event 507 3339 2832
speedo_start_xmit 1654 4349 2695
USER 2573 5081 2508
tcp_rcv_established 1336 3724 2388
__kfree_skb 640 2716 2076
net_rx_action 565 2510 1945
eth_type_trans 0 1350 1350
speedo_interrupt 5066 6262 1196
ip_route_input 868 2028 1160
tcp_prequeue_process 319 1461 1142
ip_queue_xmit 805 1886 1081
speedo_refill_rx_buf 0 1045 1045
ip_rcv 872 1912 1040
tcp_event_data_recv 334 1344 1010
skb_copy_and_csum_datagram_iovec 383 1393 1010
netif_rx 361 1360 999
mcount 1298 2261 963
tcp_transmit_skb 984 1877 893
tcp_v4_do_rcv 285 1169 884
sock_recvmsg 479 1358 879
speedo_tx_buffer_gc 388 1239 851
tcp_copy_to_iovec 356 1138 782
kmalloc 379 1154 775
ip_output 575 1333 758
sys_recvfrom 404 1105 701
alloc_skb 249 936 687
skb_release_data 249 882 633
fget 300 901 601
fput 524 1124 600
sock_wfree 0 600 600
inet_recvmsg 0 596 596
__switch_to 927 1522 595
qdisc_restart 0 568 568
speedo_refill_rx_buffers 0 568 568
dev_queue_xmit 409 952 543
check_pgt_cache 0 483 483
kfree 556 1015 459
ip_local_deliver 362 808 446
__generic_copy_to_user 0 429 429
tcp_send_delayed_ack 0 405 405
tcp_v4_checksum_init 0 391 391
cpu_idle 0 386 386
skb_copy_and_csum_datagram 428 805 377
pfifo_fast_enqueue 0 350 350
cleanup_rbuf 430 736 306
kfree_skbmem 391 696 305
pfifo_fast_dequeue 0 304 304
__generic_copy_from_user 224 501 277
sys_recv 216 488 272
csum_partial 514 781 267
remove_wait_queue 233 487 254
add_wait_queue 267 430 163
system_call 772 918 146
sockfd_lookup 232 370 138
schedule_timeout 238 314 76
do_gettimeofday 876 919 43
sys_socketcall 872 887 15
do_check_pgt_cache 584 494 -90

>>> For sometime now, I have been thinking of implementing/supporting
>>> PME's (Peformance Monitoring Events and Counters), so that we can
>>> get real values (atleast on x86) as compared to our guesses about
>>> cacheline bouncing, etc. Do you know if somebody is already doing
>>> this?
>
>>You can use SGI kernprof to measure PMCs. See the SGI oss
>>website for details. You can count L2_LINES_IN event to
>>get a measure of cache line bouncing.
>
>I have profiled L2_LINES_OUT on netperf tcp_stream workload.
>The following is the profiling from a 100mb ethernet tcp_stream
>4 adapter test baseline 2.4.17 kernel:
>
>poll_idle [c0105280]: 121743
>csum_partial_copy_generic [c0277f60]: 27951
>schedule [c0114190]: 24853
>do_softirq [c011b9e0]: 9130
>mod_timer [c011eb10]: 6997
>tcp_v4_rcv [c0258b70]: 6449
>speedo_interrupt [c01a83e0]: 6262
>__wake_up [c0114720]: 6143
>tcp_recvmsg [c0249930]: 5199
>USER [c0124a70]: 5081
>speedo_start_xmit [c01a7fc0]: 4349
>tcp_rcv_established [c0250c90]: 3724
>tcp_data_wait [c02496d0]: 3610
>speedo_rx [c01a8900]: 3358
>handle_IRQ_event [c0108a60]: 3339
>__kfree_skb [c0230520]: 2716
>net_rx_action [c0233f10]: 2510
>mcount [c02784e0]: 2261
>ip_route_input [c023ee40]: 2028
>ip_rcv [c0241180]: 1912
>ip_queue_xmit [c0243950]: 1886
>tcp_transmit_skb [c0252400]: 1877
>__switch_to [c01059d0]: 1522
>tcp_prequeue_process [c0249860]: 1461
>skb_copy_and_csum_datagram_iovec [c0232590]: 1393
>netif_rx [c0233ba0]: 1360
>sock_recvmsg [c022cfc0]: 1358
>eth_type_trans [c023a260]: 1350
>tcp_event_data_recv [c024c320]: 1344
>ip_output [c0243810]: 1333
>speedo_tx_buffer_gc [c01a81d0]: 1239
>tcp_v4_do_rcv [c0258a50]: 1169
>kmalloc [c012dda0]: 1154
>tcp_copy_to_iovec [c0250ae0]: 1138
>fput [c0136d30]: 1124
>sys_recvfrom [c022df40]: 1105
>speedo_refill_rx_buf [c01a86d0]: 1045
>kfree [c012df90]: 1015
>dev_queue_xmit [c0233860]: 952
>alloc_skb [c02301e0]: 936
>do_gettimeofday [c010c520]: 919
>system_call [c01070d8]: 918
>fget [c0136e30]: 901
>sys_socketcall [c022e610]: 887
>skb_release_data [c0230420]: 882
>ip_local_deliver [c0241020]: 808
>skb_copy_and_csum_datagram [c02322a0]: 805
>csum_partial [c0277e78]: 781
>cleanup_rbuf [c02495d0]: 736
>kfree_skbmem [c02304b0]: 696
>sock_wfree [c022f380]: 600
>inet_recvmsg [c0264720]: 596
>speedo_refill_rx_buffers [c01a88b0]: 568
>qdisc_restart [c023a4e0]: 568
>__generic_copy_from_user [c02781d0]: 501
>do_check_pgt_cache [c0112de0]: 494
>sys_recv [c022e020]: 488
>remove_wait_queue [c0115930]: 487
>check_pgt_cache [c0124b30]: 483
>add_wait_queue [c01158b0]: 430
>__generic_copy_to_user [c0278180]: 429
>tcp_send_delayed_ack [c0254e30]: 405
>tcp_v4_checksum_init [c0258930]: 391
>cpu_idle [c01052b0]: 386
>sockfd_lookup [c022cd70]: 370
>pfifo_fast_enqueue [c023a940]: 350
>schedule_timeout [c0114060]: 314
>pfifo_fast_dequeue [c023a9c0]: 304
>
>
>To eliminate the cache-line bouncing, I applied IRQ and PROCESS
>affinity. The L2_CACHE_LINES_OUT profiling with affinity:
>
>poll_idle [c0105280]: 72241
>csum_partial_copy_generic [c0289500]: 13838
>schedule [c0114190]: 9036
>speedo_interrupt [c01b9980]: 5066
>do_softirq [c011b9e0]: 3922
>USER [c0124c80]: 2573
>tcp_recvmsg [c025aed0]: 2154
>__wake_up [c0114720]: 1779
>speedo_start_xmit [c01b9560]: 1654
>mod_timer [c011eb10]: 1551
>tcp_rcv_established [c0262230]: 1336
>mcount [c0289a80]: 1298
>tcp_transmit_skb [c02639a0]: 984
>__switch_to [c01059d0]: 927
>do_gettimeofday [c010c520]: 876
>sys_socketcall [c023fbb0]: 872
>ip_rcv [c0252720]: 872
>ip_route_input [c02503e0]: 868
>ip_queue_xmit [c0254ef0]: 805
>system_call [c01070d8]: 772
>tcp_data_wait [c025ac70]: 748
>__kfree_skb [c0241ac0]: 640
>tcp_v4_rcv [c026a110]: 629
>do_check_pgt_cache [c0112de0]: 584
>ip_output [c0254db0]: 575
>net_rx_action [c02454b0]: 565
>kfree [c012e1a0]: 556
>fput [c0136f40]: 524
>csum_partial [c0289418]: 514
>handle_IRQ_event [c0108a60]: 507
>sock_recvmsg [c023e560]: 479
>cleanup_rbuf [c025ab70]: 430
>skb_copy_and_csum_datagram [c0243840]: 428
>dev_queue_xmit [c0244e00]: 409
>sys_recvfrom [c023f4e0]: 404
>kfree_skbmem [c0241a50]: 391
>speedo_tx_buffer_gc [c01b9770]: 388
>skb_copy_and_csum_datagram_iovec [c0243b30]: 383
>kmalloc [c012dfb0]: 379
>ip_local_deliver [c02525c0]: 362
>netif_rx [c0245140]: 361
>tcp_copy_to_iovec [c0262080]: 356
>tcp_event_data_recv [c025d8c0]: 334
>tcp_prequeue_process [c025ae00]: 319
>fget [c0137040]: 300
>tcp_v4_do_rcv [c0269ff0]: 285
>add_wait_queue [c01158b0]: 267
>skb_release_data [c02419c0]: 249
>alloc_skb [c0241780]: 249
>schedule_timeout [c0114060]: 238
>remove_wait_queue [c0115930]: 233
>sockfd_lookup [c023e310]: 232
>__generic_copy_from_user [c0289770]: 224
>sys_recv [c023f5c0]: 216
>
>
>Regards,
> Mala
>
>
> Mala Anand
> E-mail:manand@us.ibm.com
> Linux Technology Center - Performance
> Phone:838-8088; Tie-line:678-8088

-
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/

\
 
 \ /
  Last update: 2005-03-22 13:26    [from the cache]
©2003-2011 Jasper Spaans. Advertise on this site