Re: Process accounting/timing has broken recently

On 12/5/10 10:19 PM, Garrett Cooper wrote:
> On Sun, Dec 5, 2010 at 10:12 PM, Steve Kargl
> <sgk_at_troutmask.apl.washington.edu>  wrote:
>> On Sun, Dec 05, 2010 at 04:00:32PM -0800, Julian Elischer wrote:
>>> On 12/5/10 3:18 PM, Steve Kargl wrote:
>>>> Sometime in the last 7-10 days, some one made a
>>>> change that has broken process accounting/timing.
>>>>
>>>> laptop:kargl[42] foreach i ( 0 1 2 3 4 5 6 7 8 9 )
>>>> foreach? time ./testf
>>>> foreach? end
>>>> Max ULP: 0.501607 for x in [-18.000000:88.709999] with dx = 1.067100e-04
>>>>         69.55 real        38.39 user        30.94 sys
>>>> Max ULP: 0.501607 for x in [-18.000000:88.709999] with dx = 1.067100e-04
>>>>         68.82 real        40.95 user        27.60 sys
>>>> Max ULP: 0.501607 for x in [-18.000000:88.709999] with dx = 1.067100e-04
>>>>         69.14 real        38.90 user        30.02 sys
>>>> Max ULP: 0.501607 for x in [-18.000000:88.709999] with dx = 1.067100e-04
>>>>         68.79 real        40.59 user        27.99 sys
>>>> Max ULP: 0.501607 for x in [-18.000000:88.709999] with dx = 1.067100e-04
>>>>         68.93 real        39.76 user        28.96 sys
>>>> Max ULP: 0.501607 for x in [-18.000000:88.709999] with dx = 1.067100e-04
>>>>         68.71 real        41.21 user        27.29 sys
>>>> Max ULP: 0.501607 for x in [-18.000000:88.709999] with dx = 1.067100e-04
>>>>         69.05 real        39.68 user        29.15 sys
>>>> Max ULP: 0.501607 for x in [-18.000000:88.709999] with dx = 1.067100e-04
>>>>         68.99 real        39.98 user        28.80 sys
>>>> Max ULP: 0.501607 for x in [-18.000000:88.709999] with dx = 1.067100e-04
>>>>         69.02 real        39.64 user        29.16 sys
>>>> Max ULP: 0.501607 for x in [-18.000000:88.709999] with dx = 1.067100e-04
>>>>         69.38 real        37.49 user        31.67 sys
>>>>
>>>> testf is a numerically intensive program that tests the
>>>> accuracy of expf() in a tight loop.  User time varies
>>>> by ~3 seconds on my lightly loaded 2 GHz core2 duo processor.
>>>> I'm fairly certain that the code does not suddenly grow/loose
>>>> 6 GFLOP of operations.
>>>>
>>> I know it's a lot to ask but it may be something that you can help
>>> with if you
>>> had the time to triangulate in on the change that did it..
>>> I presume that since you are an "old hand" you can check out sources
>>> at different revisions..
>> I was hoping that someone (possibly the person responsible) would
>> recognize the symptoms and recommend a revision or two to revert.
>> Otherwise, doing a binary search will take some time in that it
>> takes 4+ hours for a buildworld/kernel cycle on my laptop.
>      If you can provide the source for the application you're running
> above and instructions on how to compile it, I can at least give you a
> bit of a head start :).
> Thanks,
> -Garrett
>
plus which probably just
`cd /sys/amd64/conf config GENERIC;cd ../compile/GENERIC; make 
kernel`  would be enough...