Date: Sun, 05 Dec 2010 22:22:35 -0800 From: Julian Elischer <julian@freebsd.org> To: Garrett Cooper <gcooper@freebsd.org> Cc: freebsd-current@freebsd.org, Steve Kargl <sgk@troutmask.apl.washington.edu> Subject: Re: Process accounting/timing has broken recently Message-ID: <4CFC812B.9060505@freebsd.org> In-Reply-To: <AANLkTikVDUPFM6Twdz%2B367APxLPS4fswfbqv0m_KLMan@mail.gmail.com> References: <20101205231829.GA68156@troutmask.apl.washington.edu> <4CFC27A0.8000406@freebsd.org> <20101206061230.GA69477@troutmask.apl.washington.edu> <AANLkTikVDUPFM6Twdz%2B367APxLPS4fswfbqv0m_KLMan@mail.gmail.com>
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On 12/5/10 10:19 PM, Garrett Cooper wrote: > On Sun, Dec 5, 2010 at 10:12 PM, Steve Kargl > <sgk@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...
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