[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Octave-bug-tracker] [bug #37509] `load -z` is very slow
From: |
Elias Pipping |
Subject: |
[Octave-bug-tracker] [bug #37509] `load -z` is very slow |
Date: |
Fri, 05 Oct 2012 16:28:50 +0000 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.10 (KHTML, like Gecko) Chrome/23.0.1262.0 Safari/537.10 |
URL:
<http://savannah.gnu.org/bugs/?37509>
Summary: `load -z` is very slow
Project: GNU Octave
Submitted by: pipping
Submitted on: Fri 05 Oct 2012 04:28:49 PM GMT
Category: None
Severity: 3 - Normal
Priority: 5 - Normal
Item Group: Regression
Status: None
Assigned to: None
Originator Name:
Originator Email:
Open/Closed: Open
Discussion Lock: Any
Release: 3.6.3
Operating System: GNU/Linux
_______________________________________________________
Details:
The following script
<<<<SNIP
function testcase(n)
system("rm -f random.dat random.dat.gz");
A=rand(1,n);
save -z random.dat.gz A;
# Use -z to uncompress
tic;
load random.dat.gz;
fprintf(stderr, "Direct: %en", toc());
# Uncompress manually
tic;
system("gunzip random.dat.gz");
load random.dat;
fprintf(stderr, "Indirect: %en", toc());
<<<<SNAP
creates a random 1xn matrix, and writes it to a gzip-compressed file. Then it
compares how long it takes to
(1) read it using `load -z` and to
(2) uncompress it through a call to gunzip and then `load` it.
While the overhead for the call to gzip dominates at first, with n=10000,
`load -z` is three orders of magnitudes slower than the indirect approach for
me:
% octave --eval 'testcase(1000)' >/dev/null
Direct: 2.528620e-01
Indirect: 1.927996e-02
% octave --eval 'testcase(10000)' >/dev/null
Direct: 2.424446e+01
Indirect: 3.546500e-02
I can reproduce this with octave 3.6.3 on two machines.
Octave 3.2.4, which is installed on one of those machines as well, does not
show this behaviour:
% /usr/bin/octave --eval 'testcase(10000)' >/dev/null
Direct: 1.430511e-02
Indirect: 1.741195e-02
_______________________________________________________
Reply to this item at:
<http://savannah.gnu.org/bugs/?37509>
_______________________________________________
Message sent via/by Savannah
http://savannah.gnu.org/
- [Octave-bug-tracker] [bug #37509] `load -z` is very slow,
Elias Pipping <=
- [Octave-bug-tracker] [bug #37509] `load -z` is very slow, Elias Pipping, 2012/10/05
- [Octave-bug-tracker] [bug #37509] `load -z` is very slow, Elias Pipping, 2012/10/05
- [Octave-bug-tracker] [bug #37509] `load -z` is very slow, Elias Pipping, 2012/10/05
- [Octave-bug-tracker] [bug #37509] `load -z` is very slow, Jordi GutiƩrrez Hermoso, 2012/10/05
- [Octave-bug-tracker] [bug #37509] `load -z` is very slow, Mike Miller, 2012/10/05
- [Octave-bug-tracker] [bug #37509] `load -z` is very slow, Mike Miller, 2012/10/05
- [Octave-bug-tracker] [bug #37509] `load -z` is very slow, Mike Miller, 2012/10/06
- [Octave-bug-tracker] [bug #37509] `load -z` is very slow, Jordi GutiƩrrez Hermoso, 2012/10/07
- [Octave-bug-tracker] [bug #37509] `load -z` is very slow, Mike Miller, 2012/10/07
- [Octave-bug-tracker] [bug #37509] `load -z` is very slow, Rik, 2012/10/11