April 2011 - gsll-devel - mailman3.common-lisp.net

[GSLL-devel] [GSD] Time making large foreign-arrays vs large arrays
by Sumant Oemrawsingh 03 May '11

03 May '11

Hi, I ran into a problem making foreign arrays. I have a two lists of lists of floats called *data-50* and *data-1024*, which are to be used as the initial contents of a matrix (first is 50x50, second 1024x1024). I do the following: CL-USER> (time (type-of (make-grid '((array) single-float) :initial-contents *data-50*))) Evaluation took: 0.000 seconds of real time 0.000000 seconds of total run time (0.000000 user, 0.000000 system) 100.00% CPU 228,096 processor cycles 27,744 bytes consed (SIMPLE-ARRAY SINGLE-FLOAT (50 50)) CL-USER> (time (type-of (make-grid '((foreign-array) single-float) :initial-contents *data-50*))) Evaluation took: 0.036 seconds of real time 0.026995 seconds of total run time (0.026995 user, 0.000000 system) 75.00% CPU 79,104,003 processor cycles 294,688 bytes consed MATRIX-SINGLE-FLOAT With a 50x50 array, everything works out fine. However, when moving to the 1024x1024 data: CL-USER> (time (type-of (make-grid '((array) single-float) :initial-contents *data-1024*))) Evaluation took: 0.036 seconds of real time 0.035995 seconds of total run time (0.034995 user, 0.001000 system) 100.00% CPU 80,301,650 processor cycles 4,194,320 bytes consed (SIMPLE-ARRAY SINGLE-FLOAT (1024 1024)) CL-USER> (time (type-of (make-grid '((foreign-array) single-float) :initial-contents *data-1024*))) Evaluation took: 686.167 seconds of real time 683.878034 seconds of total run time (683.608075 user, 0.269959 system) [ Run times consist of 0.196 seconds GC time, and 683.683 seconds non-GC time. ] 99.67% CPU 3 forms interpreted 1,502,208,488,440 processor cycles 59,838,352 bytes consed before it was aborted by a non-local transfer of control. ; Evaluation aborted on NIL. After over 10 minutes of intensive work, I gave up and aborted. When using make-foreign-array directly, instead of make-grid, I get the same problem. I would understand that foreign arrays take a bit more time to make; in the *data-50* example, about an order of magnitude more bytes were consed to make the foreign array (and needing more processor cycles). While this is not very thorough, I would expect there to be some linear relation between the array size and the time it takes. E.g. 50x50 foreign array takes less than a 0.1 second, so I would expect 1024x1024 to take less than 42.0 seconds. While that is still a long time for a normal-sized array, clearly, this is not the case. I can run some more tests later to find out where the problem lies. Or is this a known bug or limitation for foreign arrays and sbcl? Or am I just doing something wrong here? Thanks, Sumant -- Sumant Oemrawsingh

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[GSLL-devel] [PATCH] ode-system: 'next-step' should be exported
by Fedor Bezrukov 08 Apr '11

08 Apr '11

I guess next-step should be exported --- ordinary-differential-equations/ode-system.lisp | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/ordinary-differential-equations/ode-system.lisp b/ordinary-differential-equations/ode-system.lisp index 2e0490f..851b5ac 100644 --- a/ordinary-differential-equations/ode-system.lisp +++ b/ordinary-differential-equations/ode-system.lisp @@ -20,7 +20,7 @@ (in-package :gsl) -(export '(with-ode-integration)) +(export '(with-ode-integration next-step)) (defmacro with-ode-integration ((function time step-size max-time dependent dimensions -- 1.7.4.2

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[GSLL-devel] FFT speed, tests
by Sumant Oemrawsingh 04 Apr '11

04 Apr '11

Hi Liam, Today, I had some time to take a look at the (slow) speed of the FFT tests. I found that having the tests as is and adding declarations only gives a speed-up of (barely) 10%. I think I'll need to thoroughly rewrite the tests to find/solve the problem. I need to do this anyway, since a small number of tests still keeps on failing and I haven't been able to track down _that_ problem yet. As such, I'll begin "from scratch", rewriting each test. This might take some time, and due to a shortage of that due to work-related things, this might take even longer than anticipated. This situation is quite annoying since, naturally, the FFT tests should be enabled in the gsll-tests package, and not only for completeness. I'll do my best allocating time to this. Regards, Sumant -- Sumant Oemrawsingh Sikander on #lisp

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