lkml.org 
[lkml]   [2002]   [Sep]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectPerformance issue in 2.5.32+
I've noticed a significant performance hit on my system since 2.5.32.  
lmbench shows major changes in context switching latencies for 2.5.32 and
2.5.33 (see below, and profiling results for lat_ctx after that). This is
on a dual celeron system with a Gigabyte GA6BXD motherboard. I can
provide more hardware and configuration details if required.


L M B E N C H 2 . 0 S U M M A R Y
------------------------------------

Basic system parameters
----------------------------------------------------
Host OS Description Mhz
--------- ------------- ----------------------- ----
test1 Linux 2.4.19 i686-pc-linux-gnu 548
test1 Linux 2.5.31 i686-pc-linux-gnu 547
test1 Linux 2.5.32 i686-pc-linux-gnu 547
test1 Linux 2.5.33 i686-pc-linux-gnu 547
Processor, Processes - times in microseconds - smaller is better
----------------------------------------------------------------
Host OS Mhz null null open selct sig sig fork exec sh
call I/O stat clos TCP inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ----- ---- ---- ---- ---- ----
test1 Linux 2.4.19 548 0.64 1.09 6.04 8.10 49.9 1.52 4.81 498. 1399 6546
test1 Linux 2.5.31 547 0.61 1.15 6.77 9.91 44.2 1.48 5.12 576. 1698 7381
test1 Linux 2.5.32 547 0.64 1.18 6.24 9.64 1.52 5.08 703. 1884 8014
test1 Linux 2.5.33 547 0.64 1.15 6.29 8.18 1.52 5.08 733. 1884 7965
Context switching - times in microseconds - smaller is better
-------------------------------------------------------------
Host OS 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K
ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw
--------- ------------- ----- ------ ------ ------ ------ ------- -------
test1 Linux 2.4.19 2.890 10.7 94.5 34.1 130.8 35.9 135.0
test1 Linux 2.5.31 7.160 12.8 64.4 21.8 131.7 38.4 133.6
test1 Linux 2.5.32 1.460 1085.4 95.1 333.1 1078.8 200.6 634.3
test1 Linux 2.5.33 2.080 9.4200 93.8 37.4 1096.0 212.3 1079.8
*Local* Communication latencies in microseconds - smaller is better
-------------------------------------------------------------------
Host OS 2p/0K Pipe AF UDP RPC/ TCP RPC/ TCP
ctxsw UNIX UDP TCP conn
--------- ------------- ----- ----- ---- ----- ----- ----- ----- ----
test1 Linux 2.4.19 2.890 13.0 39.2 60.7 120.
test1 Linux 2.5.31 7.160 9.213 17.5 62.0 121.
test1 Linux 2.5.32 1.460 10.5 18.8 48.7 249.
test1 Linux 2.5.33 2.080 10.5 17.9 8018. 192.
File & VM system latencies in microseconds - smaller is better
--------------------------------------------------------------
Host OS 0K File 10K File Mmap Prot Page
Create Delete Create Delete Latency Fault Fault
--------- ------------- ------ ------ ------ ------ ------- ----- -----
test1 Linux 2.4.19 117.2 36.4 316.4 73.6 1811.0 1.234 4.00000
test1 Linux 2.5.31 123.6 40.5 341.5 83.5 3120.0 1.316 5.00000
test1 Linux 2.5.32 125.4 41.4 25.6K 5988.0 3224.0 1.223 5.00000
test1 Linux 2.5.33 121.5 38.8 198.5 81.8 3078.0 1.327 5.00000
*Local* Communication bandwidths in MB/s - bigger is better
-----------------------------------------------------------
Host OS Pipe AF TCP File Mmap Bcopy Bcopy Mem Mem
UNIX reread reread (libc) (hand) read write
--------- ------------- ---- ---- ---- ------ ------ ------ ------ ---- -----
test1 Linux 2.4.19 164. 145. 78.8 216.1 443.3 155.3 154.5 443. 185.3
test1 Linux 2.5.31 215. 123. 84.9 235.9 440.5 158.8 157.9 440. 199.5
test1 Linux 2.5.32 203. 103. 6.75 199.5 388.8 143.7 142.0 387. 182.2
test1 Linux 2.5.33 130. 2.42 9.07 162.7 388.7 144.8 143.1 389. 182.8
Memory latencies in nanoseconds - smaller is better
(WARNING - may not be correct, check graphs)
---------------------------------------------------
Host OS Mhz L1 $ L2 $ Main mem Guesses
--------- ------------- ---- ----- ------ -------- -------
test1 Linux 2.4.19 548 5.470 100.8 133.1
test1 Linux 2.5.31 547 5.478 87.0 133.5
test1 Linux 2.5.32 547 5.483 102.8 146.8
test1 Linux 2.5.33 547 5.483 110.8 146.5

* lat_ctx profiling data for 2.5.31:

"size=64k ovr=33.90
16 137.67
868 default_idle 13.5625
24 system_call 0.5455
14 __wake_up 0.2917
17 do_gettimeofday 0.1181
4 sys_gettimeofday 0.0250
1 pgd_alloc 0.0156
2 pte_alloc_one 0.0139
938 total 0.0077
6 schedule 0.0067
1 do_page_fault 0.0009
1 copy_process 0.0005

* lat_ctx profiling data for 2.5.32:

"size=64k ovr=33.85
16 629.19
1329 default_idle 20.7656
22 system_call 0.5000
23 __wake_up 0.4792
3 syscall_call 0.2727
1 syscall_exit 0.0909
13 do_gettimeofday 0.0903
8 sys_gettimeofday 0.0500
1 ret_from_intr 0.0417
33 schedule 0.0368
2 remove_wait_queue 0.0312
1 schedule_tail 0.0208
2 pte_alloc_one 0.0139
1445 total 0.0117
1 cpu_idle 0.0089
1 session_of_pgrp 0.0078
1 do_softirq 0.0052
1 sys_rt_sigaction 0.0042
1 do_sigaction 0.0028
1 copy_files 0.0014
1 do_exit 0.0014



- James
--
James Morris
<jmorris@intercode.com.au>


-
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 13:28    [from the cache]
©2003-2011 Jasper Spaans. Advertise on this site