Possible evidence of performance regression for 8.1-S (vs. 7.1)

David Wolfskill david at catwhisker.org
Fri Oct 29 16:58:53 UTC 2010


On Tue, Oct 26, 2010 at 10:34:08AM -0400, Mike Tancsa wrote:
> ...
> ULE is the default in 7 as well.  Perhaps remove some of the kernel 
> options not in 7, that are in 8 by default? What is the disk 
> subsystem ? just ata ?
> 
> They seem innocuous enough, but worth a try
> 
> options        HWPMC_HOOKS             # Necessary kernel hooks for hwpmc(4)
> options        MAC                     # TrustedBSD MAC Framework
> options        FLOWTABLE               # per-cpu routing cache

OK; I now have the results from testing that.

As noted earlier, we were using the MAC kernel config in 7.1, so I did
not test removing the MAC option.

I did build a kernel removing each of HWPMC_HOOKS and FLOWTABLE; results
will be shown below as being associated with os "8.1-S-".  To reduce the
need for folks to find earlier messages to see the previous results,
I'll paste them in, too:

     start        stop      real      user       sys  host    os               
1287525363  1287546846  21483.13  82628.20  21703.09  ref-7x  7.1-R+           
1287548005  1287569100  21094.63  82853.19  22185.02  ref-7x  7.1-R+           
1287570300  1287591371  21071.33  82756.81  21943.22  ref-7x  7.1-R+           
1287592592  1287614103  21511.23  82637.30  21849.90  ref-7x  7.1-R+           
1287615323  1287636770  21446.42  82715.81  21708.97  ref-7x  7.1-R+           
                                                                                
1287436357  1287461948  25590.99  81502.22  18115.07  ref-8x  8.1-S at r214029    
1287462797  1287488766  25969.26  81452.14  17920.14  ref-8x  8.1-S at r214029    
1287489641  1287515287  25645.84  81548.40  18256.52  ref-8x  8.1-S at r214029    
1287516151  1287541481  25329.64  81546.23  18294.10  ref-8x  8.1-S at r214029    
1287542355  1287568599  26244.59  81431.47  17902.39  ref-8x  8.1-S at r214029    
                                                                                
1287710312  1287732046  21733.20  82688.01  22108.95  ref-8x  7.1-R+           
1287733360  1287754549  21188.88  82869.09  21890.83  ref-8x  7.1-R+           
1287755881  1287777566  21684.09  82772.50  21933.74  ref-8x  7.1-R+           

1287879508  1287905173  25665.03  81696.22  18278.42  ref-8x  8.1-S[7.1-R+ user]
1287906039  1287931709  25669.48  81735.00  18265.78  ref-8x  8.1-S[7.1-R+ user]
1287932573  1287958275  25700.99  81700.40  18246.04  ref-8x  8.1-S[7.1-R+ user]
1287959144  1287984859  25714.74  81800.40  18346.57  ref-8x  8.1-S[7.1-R+ user]
1287985748  1288011752  26004.33  81569.28  17967.68  ref-8x  8.1-S[7.1-R+ user]

1288198095  1288223776  25681.17  81550.12  18442.21  ref-8x  8.1-S-
1288224673  1288250350  25676.86  81561.61  18448.39  ref-8x  8.1-S-
1288269106  1288294837  25730.45  81535.38  18396.07  ref-8x  8.1-S-
1288295688  1288321338  25649.35  81552.34  18424.28  ref-8x  8.1-S-

[Only 4 results posted, as one of the attempted builds failed.]

And here are some ministat plots.  As we have 3 "environment"
variables (which machine is used, which kernel, and which userland),
as well as 3 distinct variables being measured (real [wall clock]
time; user CPU seconds; system CPU seconds), the file names reflect
the measured variable ("real", "user", or "sys"), a "_h" to indicate
that a "host designation" ("7" or "8") follows, a "_k" to indicate
that a kernel designation follows ("7", "8", or "8-"), and a "_u" to
indicate that a userland desgnation follows ("7" or "8").

So -- real time first:

dwolf-bsd(8.1-S)[30] ministat -s real*
x real_h7_k7_u7
+ real_h8_k78_u7
* real_h8_k7_u7
: real_h8_k8-_u8
# real_h8_k8_u8
+------------------------------------------------------------------------------+
|x *   xx **                                                    #   #O@   O   #|
||___A_M|                                                                      |
|                                                                    |MA_|     |
|  |____A_M_|                                                                  |
|                                                                    |A        |
|                                                                |___M_A____|  |
+------------------------------------------------------------------------------+
    N           Min           Max        Median           Avg        Stddev
x   5      21071.33      21511.23      21446.42     21321.348     218.96441
+   5      25665.03      26004.33      25700.99     25750.914     143.20282
Difference at 95.0% confidence
        4429.57 +/- 269.817
        20.7753% +/- 1.26548%
        (Student's t, pooled s = 185.003)
*   3      21188.88       21733.2      21684.09      21535.39     301.08941
No difference proven at 95.0% confidence
:   4      25649.35      25730.45     25679.015     25684.457     33.745994
Difference at 95.0% confidence
        4363.11 +/- 264.927
        20.4636% +/- 1.24254%
        (Student's t, pooled s = 166.989)
#   5      25329.64      26244.59      25645.84     25756.064     355.43859
Difference at 95.0% confidence
        4434.72 +/- 430.527
        20.7994% +/- 2.01923%
        (Student's t, pooled s = 295.197)
dwolf-bsd(8.1-S)[31] 


User CPU:
dwolf-bsd(8.1-S)[31] ministat -s user*
x user_h7_k7_u7
+ user_h8_k7_u7
* user_h8_k8-_u8
: user_h8_k8_u7
# user_h8_k8_u9
+------------------------------------------------------------------------------+
|      O                                                                      :|
|x*    O                                                                      :|
|**   #O#                                                                     :|
|A|                                                                            |
||A                                                                            |
|      A                                                                       |
|                                                                             A|
|     |A                                                                       |
+------------------------------------------------------------------------------+
    N           Min           Max        Median           Avg        Stddev
x   5      21071.33      21511.23      21446.42     21321.348     218.96441
+   3      21188.88       21733.2      21684.09      21535.39     301.08941
No difference proven at 95.0% confidence
*   4      25649.35      25730.45     25679.015     25684.457     33.745994
Difference at 95.0% confidence
        4363.11 +/- 264.927
        20.4636% +/- 1.24254%
        (Student's t, pooled s = 166.989)
:   5      81569.28       81800.4       81700.4      81700.26     84.271865
Difference at 95.0% confidence
        60378.9 +/- 241.959
        283.185% +/- 1.13482%
        (Student's t, pooled s = 165.902)
#   5      25329.64      26244.59      25645.84     25756.064     355.43859
Difference at 95.0% confidence
        4434.72 +/- 430.527
        20.7994% +/- 2.01923%
        (Student's t, pooled s = 295.197)
dwolf-bsd(8.1-S)[32] 


Finally, system CPU:

dwolf-bsd(8.1-S)[32] ministat -s sys*
x sys_h7_k7_u7
+ sys_h8_k7_u7
* sys_h8_k8-_u8
: sys_h8_k8_u7
# sys_h8_k8_u8
+------------------------------------------------------------------------------+
|#      : **                                                         x   +     |
|#:  # ##:**                                                         x  x+x  +x|
|                                                                    |__A___|  |
|                                                                       |MA_|  |
|         AM                                                                   |
|   |__AM|                                                                     |
||___A__|                                                                      |
+------------------------------------------------------------------------------+
    N           Min           Max        Median           Avg        Stddev
x   5      21703.09      22185.02       21849.9      21878.04     199.04094
+   3      21890.83      22108.95      21933.74      21977.84     115.55385
No difference proven at 95.0% confidence
*   4      18396.07      18448.39     18433.245     18427.737     23.457507
Difference at 95.0% confidence
        -3450.3 +/- 239.945
        -15.7706% +/- 1.09674%
        (Student's t, pooled s = 151.242)
:   5      17967.68      18346.57      18265.78     18220.898      146.5163
Difference at 95.0% confidence
        -3657.14 +/- 254.882
        -16.716% +/- 1.16501%
        (Student's t, pooled s = 174.763)
#   5      17902.39       18294.1      18115.07     18097.644     182.87428
Difference at 95.0% confidence
        -3780.4 +/- 278.75
        -17.2794% +/- 1.27411%
        (Student's t, pooled s = 191.129)
dwolf-bsd(8.1-S)[33] 

Peace,
david
-- 
David H. Wolfskill				david at catwhisker.org
Depriving a girl or boy of an opportunity for education is evil.

See http://www.catwhisker.org/~david/publickey.gpg for my public key.
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