* [Buildroot] Python running very slow with buildroot 2012.05
@ 2012-09-06 14:04 Vimal Menon
2012-09-06 14:15 ` Thomas Petazzoni
0 siblings, 1 reply; 6+ messages in thread
From: Vimal Menon @ 2012-09-06 14:04 UTC (permalink / raw)
To: buildroot
Dear Team,
I happened to download and install buildroot (default 2012.05), while checking the compiled image, I saw that python runs very slow.
for eg:
On a standard linux, Python 2.7.2 complied with glibc
#time python -c "print 'hello world'"
hello world
real??? 0m0.077s
user??? 0m0.068s
sys???? 0m0.009s
and the same command ran on the same machine with the buildroot compiled image (not via qemu, but with the image booted through grub), python takes a lot more time
#time python -c "print 'hello world'"
hello world
real??? 0m 0.28s
user??? 0m 0.26s
sys???? 0m 0.01s
Why would there be such a huge difference? What might I have done wrong? Has anybody of you come across such a situation?
Thanks,
Vimal
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* [Buildroot] Python running very slow with buildroot 2012.05
2012-09-06 14:04 [Buildroot] Python running very slow with buildroot 2012.05 Vimal Menon
@ 2012-09-06 14:15 ` Thomas Petazzoni
2012-09-06 14:27 ` Vimal Menon
0 siblings, 1 reply; 6+ messages in thread
From: Thomas Petazzoni @ 2012-09-06 14:15 UTC (permalink / raw)
To: buildroot
Le Thu, 6 Sep 2012 07:04:01 -0700 (PDT),
Vimal Menon <vimalmenon@yahoo.com> a ?crit :
> I happened to download and install buildroot (default 2012.05), while
> checking the compiled image, I saw that python runs very slow. for eg:
>
> On a standard linux, Python 2.7.2 complied with glibc
>
> #time python -c "print 'hello world'"
>
> hello world
>
> real??? 0m0.077s
> user??? 0m0.068s
> sys???? 0m0.009s
>
> and the same command ran on the same machine with the buildroot
> compiled image (not via qemu, but with the image booted through
> grub), python takes a lot more time
>
> #time python -c "print 'hello world'"
>
> hello world
> real??? 0m 0.28s
> user??? 0m 0.26s
> sys???? 0m 0.01s
>
> Why would there be such a huge difference? What might I have done
> wrong? Has anybody of you come across such a situation?
You're not running the C library (by default, Buildroot uses uClibc),
and maybe you're not using the same optimization flags as well.
Try to build a Buildroot system based on glibc, and use the appropriate
optimization flags, maybe it will improve the situation.
Best regards,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Buildroot] Python running very slow with buildroot 2012.05
2012-09-06 14:15 ` Thomas Petazzoni
@ 2012-09-06 14:27 ` Vimal Menon
2012-09-06 14:34 ` Thomas Petazzoni
0 siblings, 1 reply; 6+ messages in thread
From: Vimal Menon @ 2012-09-06 14:27 UTC (permalink / raw)
To: buildroot
Dear Thomas,
I checked using default installations in both the environments, can the difference between glibc and uClibc be so huge for python?
Thanks,
Vimal
?
________________________________
From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
To: Vimal Menon <vimalmenon@yahoo.com>
Cc: "buildroot at busybox.net" <buildroot@busybox.net>
Sent: Thursday, September 6, 2012 7:45 PM
Subject: Re: [Buildroot] Python running very slow with buildroot 2012.05
Le Thu, 6 Sep 2012 07:04:01 -0700 (PDT),
Vimal Menon <vimalmenon@yahoo.com> a ?crit :
> I happened to download and install buildroot (default 2012.05), while
> checking the compiled image, I saw that python runs very slow. for eg:
>
> On a standard linux, Python 2.7.2 complied with glibc
>
> #time python -c "print 'hello world'"
>
> hello world
>
> real??? 0m0.077s
> user??? 0m0.068s
> sys???? 0m0.009s
>
> and the same command ran on the same machine with the buildroot
> compiled image (not via qemu, but with the image booted through
> grub), python takes a lot more time
>
> #time python -c "print 'hello world'"
>
> hello world
> real??? 0m 0.28s
> user??? 0m 0.26s
> sys???? 0m 0.01s
>
> Why would there be such a huge difference? What might I have done
> wrong? Has anybody of you come across such a situation?
You're not running the C library (by default, Buildroot uses uClibc),
and maybe you're not using the same optimization flags as well.
Try to build a Buildroot system based on glibc, and use the appropriate
optimization flags, maybe it will improve the situation.
Best regards,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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* [Buildroot] Python running very slow with buildroot 2012.05
2012-09-06 14:27 ` Vimal Menon
@ 2012-09-06 14:34 ` Thomas Petazzoni
2012-09-06 14:40 ` Gustavo Zacarias
0 siblings, 1 reply; 6+ messages in thread
From: Thomas Petazzoni @ 2012-09-06 14:34 UTC (permalink / raw)
To: buildroot
Hello,
Le Thu, 6 Sep 2012 07:27:17 -0700 (PDT),
Vimal Menon <vimalmenon@yahoo.com> a ?crit :
> I checked using default installations in both the environments, can
What do you mean by this? You're comparing the Python that has been
built by your distro with a certain compiler and certain optimization
flags, with the Python that has been built by Buildroot using a
different compiler, with different optimization flags.
> the difference between glibc and uClibc be so huge for python?
I don't know. Maybe the dynamic linker is slower, maybe some other
parts of the C library are slower, but I'm not sure, it needs
investigation.
Is is reproducible even after the first run? Are you running the same
kernel, with the same configuration? Your two environments are really
different, so it's very difficult to make correct comparisons and draw
conclusions from them.
Best regards,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Buildroot] Python running very slow with buildroot 2012.05
2012-09-06 14:34 ` Thomas Petazzoni
@ 2012-09-06 14:40 ` Gustavo Zacarias
2012-09-06 15:11 ` Thomas Petazzoni
0 siblings, 1 reply; 6+ messages in thread
From: Gustavo Zacarias @ 2012-09-06 14:40 UTC (permalink / raw)
To: buildroot
On 09/06/12 11:34, Thomas Petazzoni wrote:
> Is is reproducible even after the first run? Are you running the same
> kernel, with the same configuration? Your two environments are really
> different, so it's very difficult to make correct comparisons and draw
> conclusions from them.
Exactly where i was going to point to.
He's basically measuring startup time, not a benchmark per se.
Also if, say, the main system is already running something with the
exact same glibc it's already preloaded, whereas if it's the first/only
thing uclibc-based it gets all the penalties, even after the first run.
Regards.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Buildroot] Python running very slow with buildroot 2012.05
2012-09-06 14:40 ` Gustavo Zacarias
@ 2012-09-06 15:11 ` Thomas Petazzoni
0 siblings, 0 replies; 6+ messages in thread
From: Thomas Petazzoni @ 2012-09-06 15:11 UTC (permalink / raw)
To: buildroot
Le Thu, 06 Sep 2012 11:40:39 -0300,
Gustavo Zacarias <gustavo@zacarias.com.ar> a ?crit :
> Also if, say, the main system is already running something with the
> exact same glibc it's already preloaded, whereas if it's the
> first/only thing uclibc-based it gets all the penalties, even after
> the first run. Regards.
Aaah, good point. Most likely his Linux distro has gazillions of
programs already running, so most of the glibc code is already in
memory. If not parts of the Python interpreter code itself. While on
the Buildroot system, no Python code has been executed since boot, and
only a minimal set of userspace applications has been executed, so not
much of uClibc code is in memory.
But I would strongly suspect that the Linux distro is already running a
Python app somewhere, so the Python interpreter is in memory already.
Well, to conclude: you're comparing apples to oranges and you really
cannot draw any conclusion from your "benchmark".
Best regards,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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2012-09-06 14:04 [Buildroot] Python running very slow with buildroot 2012.05 Vimal Menon
2012-09-06 14:15 ` Thomas Petazzoni
2012-09-06 14:27 ` Vimal Menon
2012-09-06 14:34 ` Thomas Petazzoni
2012-09-06 14:40 ` Gustavo Zacarias
2012-09-06 15:11 ` Thomas Petazzoni
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