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

[Ivan Voras]

On 10/21/10 23:53, Dan Nelson wrote:
> In the last episode (Oct 20), David Wolfskill said:
>> Almost 2 years ago, we migrated from a lightly-patched 6.2-R to 7.1-R with
>> 5 commits that were made to 7.1-S backported to it.  On the same hardware
>> (not the HP mentioned above), I measured a 35% reduction in elapsed time
>> for one particular form of the build in question.  This was encouraging.
>>
>> A couple of days ago, I updated the active slice on my 8.x reference
>> machine to 8.1-STABLE #5 r214029 and proceeded to start some timed builds;
>> here are some fairly raw timing data:
>>
>>      Start        Stop      real      user       sys  OS
>> 1287436357  1287461948  25590.99  81502.22  18115.07  8.1-S
>> 1287462797  1287488766  25969.26  81452.14  17920.14  8.1-S
>> 1287489641  1287515287  25645.84  81548.40  18256.52  8.1-S
>> 1287516151  1287541481  25329.64  81546.23  18294.10  8.1-S
>> 1287542355  1287568599  26244.59  81431.47  17902.39  8.1-S
>>
>> 1287525363  1287546846  21483.13  82628.20  21703.09  7.1-R+
>> 1287548005  1287569100  21094.63  82853.19  22185.02  7.1-R+
>> 1287570300  1287591371  21071.33  82756.81  21943.22  7.1-R+
> 
> An observation:  on 8.1, both user and sys times are less, but real time is
> higher.  So 8.1 finished the build using less CPU, but spent more time
> waiting for something else.  Disk?  Network?  I don't suppose the machines

NFS?

AFAIK NFS was changed in 8.x?