Public bug reported: I noticed that a numerical solver I develop runs much slower on 16.04.1 than on 14.04. See for example this output:
The counters (top part of each result section) show that the solver does the same on both variants. The timings (lower part, beginning with FrameworkTimeWriteOutputs) are execution time in seconds. Overall time is in the last row (WallClockTime). First column shows results on Ubuntu 14.04, second column shows time on 16.04.1. ../../data/tests/CCMTest/Kirchhoff.d6p Reference New IntegratorErrorTestFails 1026 == 1026 IntegratorFunctionEvals 32474 == 32474 IntegratorLESSetup 3114 == 3114 IntegratorLESSolve 32473 == 32473 IntegratorSteps 25809 == 25809 LESJacEvals 463 == 463 LESRHSEvals 3241 == 3241 LESSetups 3114 == 3114 -- FrameworkTimeWriteOutputs 0.00 ~~ 0.00 IntegratorTimeFunctionEvals 4.96 <> 9.46 IntegratorTimeLESSetup 0.38 ~~ 0.58 IntegratorTimeLESSolve 0.36 ~~ 0.35 LESTimeJacEvals 0.08 ~~ 0.08 LESTimeRHSEvals 0.27 ~~ 0.46 WallClockTime 6.13 <> 10.79 MoistField.d6o RHField.d6o ../../data/tests/EN15026/Kirchhoff.d6p Reference New IntegratorErrorTestFails 2 == 2 IntegratorFunctionEvals 17685 == 17685 IntegratorLESSetup 903 == 903 IntegratorLESSolve 17684 == 17684 IntegratorSteps 17635 == 17635 LESJacEvals 295 == 295 LESRHSEvals 2065 == 2065 LESSetups 903 == 903 -- FrameworkTimeWriteOutputs 0.03 ~~ 0.03 IntegratorTimeFunctionEvals 31.04 <> 58.89 IntegratorTimeLESSetup 2.47 ~~ 3.76 IntegratorTimeLESSolve 3.05 ~~ 2.98 LESTimeJacEvals 0.28 ~~ 0.28 LESTimeRHSEvals 2.02 ~~ 3.30 WallClockTime 40.39 <> 69.39 Particularly affected is the physics part of the code (IntegratorTimeFunctionEvals), which does by far the most memory access and uses pow(), sqrt(), exp() functions. The test code was compiled with GCC 4.8.4 on Ubuntu 14.04 and was run unmodified on 16.04 (after upgrade and on a second machine after a fresh install). When the code is compiled with the new GCC 5.4 on Ubuntu 16.04, the execution times are approximately the same as with GCC 4.8.4 on Ubuntu 16.04. Therefore I would not think it is a GCC bug. I have a test suite archive for download and test execution prepared: http://bauklimatik-dresden.de/downloads/tmp/test_suite.tar.7z Run the test suite on 14.04 and on 16.04 and observe the numbers in the "New" column, they will differ significantly for most test cases. Can you confirm my observation? And if yes, does anyone know how to avoid this performance drop? ** Affects: ubuntu Importance: Undecided Status: New ** Description changed: I noticed that a numerical solver I develop runs much slower on 16.04.1 than on 14.04. See for example this output: The counters (top part of each result section) show that the solver does the same on both variants. The timings (lower part, beginning with FrameworkTimeWriteOutputs) are execution time in seconds. Overall time is in the last row (WallClockTime). First column shows results on Ubuntu 14.04, second column shows time on 16.04.1. <pre> ../../data/tests/CCMTest/Kirchhoff.d6p Reference New IntegratorErrorTestFails 1026 == 1026 IntegratorFunctionEvals 32474 == 32474 IntegratorLESSetup 3114 == 3114 IntegratorLESSolve 32473 == 32473 IntegratorSteps 25809 == 25809 LESJacEvals 463 == 463 LESRHSEvals 3241 == 3241 LESSetups 3114 == 3114 -- FrameworkTimeWriteOutputs 0.00 ~~ 0.00 IntegratorTimeFunctionEvals 4.96 <> 9.46 IntegratorTimeLESSetup 0.38 ~~ 0.58 IntegratorTimeLESSolve 0.36 ~~ 0.35 LESTimeJacEvals 0.08 ~~ 0.08 LESTimeRHSEvals 0.27 ~~ 0.46 WallClockTime 6.13 <> 10.79 - MoistField.d6o RHField.d6o ../../data/tests/EN15026/Kirchhoff.d6p Reference New IntegratorErrorTestFails 2 == 2 IntegratorFunctionEvals 17685 == 17685 IntegratorLESSetup 903 == 903 IntegratorLESSolve 17684 == 17684 IntegratorSteps 17635 == 17635 LESJacEvals 295 == 295 LESRHSEvals 2065 == 2065 LESSetups 903 == 903 -- FrameworkTimeWriteOutputs 0.03 ~~ 0.03 IntegratorTimeFunctionEvals 31.04 <> 58.89 IntegratorTimeLESSetup 2.47 ~~ 3.76 IntegratorTimeLESSolve 3.05 ~~ 2.98 LESTimeJacEvals 0.28 ~~ 0.28 LESTimeRHSEvals 2.02 ~~ 3.30 WallClockTime 40.39 <> 69.39 </pre> Particularly affected is the physics part of the code (IntegratorTimeFunctionEvals), which does by far the most memory access and uses pow(), sqrt(), exp() functions. The test code was compiled with GCC 4.8.4 on Ubuntu 14.04 and was run unmodified on 16.04 (after upgrade and on a second machine after a fresh install). When the code is compiled with the new GCC 5.4 on Ubuntu 16.04, the execution times are approximately the same as with GCC 4.8.4 on Ubuntu 16.04. Therefore I would not think it is a GCC bug. I have a test suite archive for download and test execution prepared: http://bauklimatik-dresden.de/downloads/tmp/test_suite.tar.7z Run the test suite on 14.04 and on 16.04 and observe the numbers in the "New" column, they will differ significantly for most test cases. - - Can you confirm my observation? And if yes, does anyone know how to avoid this performance drop? + Can you confirm my observation? And if yes, does anyone know how to + avoid this performance drop? ** Description changed: I noticed that a numerical solver I develop runs much slower on 16.04.1 than on 14.04. See for example this output: The counters (top part of each result section) show that the solver does the same on both variants. The timings (lower part, beginning with FrameworkTimeWriteOutputs) are execution time in seconds. Overall time is in the last row (WallClockTime). First column shows results on Ubuntu 14.04, second column shows time on 16.04.1. - <pre> ../../data/tests/CCMTest/Kirchhoff.d6p - Reference New - IntegratorErrorTestFails 1026 == 1026 - IntegratorFunctionEvals 32474 == 32474 - IntegratorLESSetup 3114 == 3114 - IntegratorLESSolve 32473 == 32473 - IntegratorSteps 25809 == 25809 - LESJacEvals 463 == 463 - LESRHSEvals 3241 == 3241 - LESSetups 3114 == 3114 - -- - FrameworkTimeWriteOutputs 0.00 ~~ 0.00 - IntegratorTimeFunctionEvals 4.96 <> 9.46 - IntegratorTimeLESSetup 0.38 ~~ 0.58 - IntegratorTimeLESSolve 0.36 ~~ 0.35 - LESTimeJacEvals 0.08 ~~ 0.08 - LESTimeRHSEvals 0.27 ~~ 0.46 - WallClockTime 6.13 <> 10.79 + Reference New + IntegratorErrorTestFails 1026 == 1026 + IntegratorFunctionEvals 32474 == 32474 + IntegratorLESSetup 3114 == 3114 + IntegratorLESSolve 32473 == 32473 + IntegratorSteps 25809 == 25809 + LESJacEvals 463 == 463 + LESRHSEvals 3241 == 3241 + LESSetups 3114 == 3114 + -- + FrameworkTimeWriteOutputs 0.00 ~~ 0.00 + IntegratorTimeFunctionEvals 4.96 <> 9.46 + IntegratorTimeLESSetup 0.38 ~~ 0.58 + IntegratorTimeLESSolve 0.36 ~~ 0.35 + LESTimeJacEvals 0.08 ~~ 0.08 + LESTimeRHSEvals 0.27 ~~ 0.46 + WallClockTime 6.13 <> 10.79 MoistField.d6o RHField.d6o ../../data/tests/EN15026/Kirchhoff.d6p - Reference New - IntegratorErrorTestFails 2 == 2 - IntegratorFunctionEvals 17685 == 17685 - IntegratorLESSetup 903 == 903 - IntegratorLESSolve 17684 == 17684 - IntegratorSteps 17635 == 17635 - LESJacEvals 295 == 295 - LESRHSEvals 2065 == 2065 - LESSetups 903 == 903 - -- - FrameworkTimeWriteOutputs 0.03 ~~ 0.03 - IntegratorTimeFunctionEvals 31.04 <> 58.89 - IntegratorTimeLESSetup 2.47 ~~ 3.76 - IntegratorTimeLESSolve 3.05 ~~ 2.98 - LESTimeJacEvals 0.28 ~~ 0.28 - LESTimeRHSEvals 2.02 ~~ 3.30 - WallClockTime 40.39 <> 69.39 - </pre> + Reference New + IntegratorErrorTestFails 2 == 2 + IntegratorFunctionEvals 17685 == 17685 + IntegratorLESSetup 903 == 903 + IntegratorLESSolve 17684 == 17684 + IntegratorSteps 17635 == 17635 + LESJacEvals 295 == 295 + LESRHSEvals 2065 == 2065 + LESSetups 903 == 903 + -- + FrameworkTimeWriteOutputs 0.03 ~~ 0.03 + IntegratorTimeFunctionEvals 31.04 <> 58.89 + IntegratorTimeLESSetup 2.47 ~~ 3.76 + IntegratorTimeLESSolve 3.05 ~~ 2.98 + LESTimeJacEvals 0.28 ~~ 0.28 + LESTimeRHSEvals 2.02 ~~ 3.30 + WallClockTime 40.39 <> 69.39 - Particularly affected is the physics part of the code - (IntegratorTimeFunctionEvals), which does by far the most memory access - and uses pow(), sqrt(), exp() functions. + + Particularly affected is the physics part of the code (IntegratorTimeFunctionEvals), which does by far the most memory access and uses pow(), sqrt(), exp() functions. The test code was compiled with GCC 4.8.4 on Ubuntu 14.04 and was run unmodified on 16.04 (after upgrade and on a second machine after a fresh install). When the code is compiled with the new GCC 5.4 on Ubuntu 16.04, the execution times are approximately the same as with GCC 4.8.4 on Ubuntu 16.04. Therefore I would not think it is a GCC bug. I have a test suite archive for download and test execution prepared: http://bauklimatik-dresden.de/downloads/tmp/test_suite.tar.7z Run the test suite on 14.04 and on 16.04 and observe the numbers in the "New" column, they will differ significantly for most test cases. Can you confirm my observation? And if yes, does anyone know how to avoid this performance drop? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1613996 Title: 30% slowdown in numerical solver exection on 16.04.1 vs. 14.04 with same solver binary To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1613996/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
