|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] Poor SMP performance pv_ops domU
I've tried with various kernel's today - pv_ops seems to only use 1 core out of
8.
PV spinlocks makes no difference.
The thing that sticks out most is I cannot get the dom0 (xen-3.4.2) to show
more that about 99.7% cpu usage for any pv_ops kernel.
#!/usr/bin/perl
while () {}
running 8 of these loads 2.6.18.8-xenU with nearly 800% cpu as shown in dom0
running the same 8 in any pv_ops kernel's only gets as high as about 99.7%
Inside the pv and xenU kernels top -s show all 8 cores being used.
John
On 18 May 2010, at 19:38, Jeremy Fitzhardinge wrote:
> On 05/18/2010 10:34 AM, John Morrison wrote:
>> Hi,
>>
>> Over the last year we have tried many times to get acceptable performance
>> from pv_ops kernels.
>>
>> Tests done with 1,2,4 and 8 cores. The more cores the lower the score.
>>
>> Inside the domU it shows all cores, top -s shows all cores in use.
>> xentop in dom0 never shows over 99% cpu.
>>
>> 2.6.18.8-xenU kernel show's over 700% cpu and the scores are about 8 x the
>> pv_ops score.
>>
>> Any ideas ?
>>
>
> Well, I guess some kind of bad serialization is going on in there, and
> it should be fairly obvious with a bit of examination.
>
> Have you tried building your own pvops domu kernels? Does enabling PV
> spinlocks make any difference? Also enabling some of the lock
> debugging/profiling/contention monitoring stuff may give useful results.
>
> Can you post the corresponding 2.6.18 results? Are there specific
> sub-tests which show the effect more strongly than the others?
>
> How does the 2.6.32 kernel fare when booted native?
>
> Thanks,
> J
>
>>
>> John
>>
>>
>> 1 core
>>
>> BYTE UNIX Benchmarks (Version 4.1-wht.2)
>> System -- Linux test 2.6.32-21-server #32-Ubuntu SMP Fri Apr 16 09:17:34 UTC
>> 2010 x86_64 GNU/Linux
>> /dev/xvda1 141110136 1066476 132875660 1% /
>>
>> Start Benchmark Run: Tue May 18 13:54:54 BST 2010
>> 13:54:54 up 0 min, 1 user, load average: 0.00, 0.00, 0.00
>>
>> End Benchmark Run: Tue May 18 14:06:12 BST 2010
>> 14:06:12 up 11 min, 2 users, load average: 11.48, 5.20, 2.43
>>
>>
>> INDEX VALUES
>> TEST BASELINE RESULT INDEX
>>
>> Dhrystone 2 using register variables 376783.7 8950813.0 237.6
>> Double-Precision Whetstone 83.1 2103.7 253.2
>> Execl Throughput 188.3 1568.4 83.3
>> File Copy 1024 bufsize 2000 maxblocks 2672.0 64198.0 240.3
>> File Copy 256 bufsize 500 maxblocks 1077.0 17781.0 165.1
>> File Read 4096 bufsize 8000 maxblocks 15382.0 643717.0 418.5
>> Pipe-based Context Switching 15448.6 85379.4 55.3
>> Pipe Throughput 111814.6 478490.1 42.8
>> Process Creation 569.3 3329.6 58.5
>> Shell Scripts (8 concurrent) 44.8 380.7 85.0
>> System Call Overhead 114433.5 498712.3 43.6
>> =========
>> FINAL SCORE 114.1
>>
>> 2-cores
>>
>> ==============================================================
>> BYTE UNIX Benchmarks (Version 4.1-wht.2)
>> System -- Linux test 2.6.32-21-server #32-Ubuntu SMP Fri Apr 16 09:17:34 UTC
>> 2010 x86_64 GNU/Linux
>> /dev/xvda1 141110136 1066548 132875588 1% /
>>
>> Start Benchmark Run: Tue May 18 14:07:27 BST 2010
>> 14:07:27 up 0 min, 1 user, load average: 0.00, 0.00, 0.00
>>
>> End Benchmark Run: Tue May 18 14:18:04 BST 2010
>> 14:18:04 up 10 min, 1 user, load average: 12.78, 5.53, 2.49
>>
>>
>> INDEX VALUES
>> TEST BASELINE RESULT INDEX
>>
>> Dhrystone 2 using register variables 376783.7 10124838.6 268.7
>> Double-Precision Whetstone 83.1 1188.7 143.0
>> Execl Throughput 188.3 1596.2 84.8
>> File Copy 1024 bufsize 2000 maxblocks 2672.0 58323.0 218.3
>> File Copy 256 bufsize 500 maxblocks 1077.0 17776.0 165.1
>> File Read 4096 bufsize 8000 maxblocks 15382.0 568217.0 369.4
>> Pipe-based Context Switching 15448.6 86111.3 55.7
>> Pipe Throughput 111814.6 469957.8 42.0
>> Process Creation 569.3 3298.1 57.9
>> Shell Scripts (8 concurrent) 44.8 378.9 84.6
>> System Call Overhead 114433.5 532828.4 46.6
>> =========
>> FINAL SCORE 107.9
>>
>> 4-cores
>>
>> ==============================================================
>> BYTE UNIX Benchmarks (Version 4.1-wht.2)
>> System -- Linux test 2.6.32-21-server #32-Ubuntu SMP Fri Apr 16 09:17:34 UTC
>> 2010 x86_64 GNU/Linux
>> /dev/xvda1 141110136 1066628 132875508 1% /
>>
>> Start Benchmark Run: Tue May 18 14:19:17 BST 2010
>> 14:19:17 up 0 min, 1 user, load average: 0.00, 0.00, 0.00
>>
>> End Benchmark Run: Tue May 18 14:29:53 BST 2010
>> 14:29:53 up 10 min, 1 user, load average: 13.59, 6.35, 2.97
>>
>>
>> INDEX VALUES
>> TEST BASELINE RESULT INDEX
>>
>> Dhrystone 2 using register variables 376783.7 10185429.8 270.3
>> Double-Precision Whetstone 83.1 759.8 91.4
>> Execl Throughput 188.3 1386.2 73.6
>> File Copy 1024 bufsize 2000 maxblocks 2672.0 62331.0 233.3
>> File Copy 256 bufsize 500 maxblocks 1077.0 16492.0 153.1
>> File Read 4096 bufsize 8000 maxblocks 15382.0 563402.0 366.3
>> Pipe-based Context Switching 15448.6 87176.0 56.4
>> Pipe Throughput 111814.6 481068.1 43.0
>> Process Creation 569.3 3128.9 55.0
>> Shell Scripts (8 concurrent) 44.8 394.9 88.1
>> System Call Overhead 114433.5 539996.1 47.2
>> =========
>> FINAL SCORE 102.6
>> 8-cores
>>
>> ==============================================================
>> BYTE UNIX Benchmarks (Version 4.1-wht.2, 8 threads)
>> System -- Linux test 2.6.32-21-server #32-Ubuntu SMP Fri Apr 16 09:17:34 UTC
>> 2010 x86_64 GNU/Linux
>> /dev/xvda1 141110136 1066680 132875456 1% /
>>
>> Start Benchmark Run: Tue May 18 14:30:59 BST 2010
>> 14:30:59 up 0 min, 1 user, load average: 0.07, 0.02, 0.00
>>
>> End Benchmark Run: Tue May 18 14:42:52 BST 2010
>> 14:42:52 up 12 min, 1 user, load average: 25.56, 10.84, 4.96
>>
>>
>> INDEX VALUES
>> TEST BASELINE RESULT INDEX
>>
>> Dhrystone 2 using register variables 376783.7 9972130.3 264.7
>> Double-Precision Whetstone 83.1 755.2 90.9
>> Execl Throughput 188.3 1584.7 84.2
>> File Copy 1024 bufsize 2000 maxblocks 2672.0 58981.0 220.7
>> File Copy 256 bufsize 500 maxblocks 1077.0 16904.0 157.0
>> File Read 4096 bufsize 8000 maxblocks 15382.0 557735.0 362.6
>> Pipe-based Context Switching 15448.6 80738.2 52.3
>> Pipe Throughput 111814.6 450891.2 40.3
>> Process Creation 569.3 2948.5 51.8
>> Shell Scripts (8 concurrent) 44.8 378.1 84.4
>> System Call Overhead 114433.5 537443.2 47.0
>> =========
>> FINAL SCORE 100.9
>>
>>
>>
>> --
>> Professional hosting without compromise
>> www.clustered.net
>>
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>> http://lists.xensource.com/xen-devel
>>
>>
>
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |