optimized script [Was: ARM defconfig files]

optimized script [Was: ARM defconfig files]

[Uwe Kleine-König]

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Hello,

On Tue, Jul 13, 2010 at 09:07:41AM +0200, Uwe Kleine-König wrote:
> Hi
> 
> On Mon, Jul 12, 2010 at 01:50:47PM -0600, Grant Likely wrote:
> > On Mon, Jul 12, 2010 at 1:34 PM, Linus Torvalds
> > <torvalds@linux-foundation.org> wrote:
> > > On Mon, Jul 12, 2010 at 12:17 PM, Nicolas Pitre <nico@fluxnic.net> wrote:
> > >> I think Uwe could provide his script and add it to the kernel tree.
> > >> Then all architectures could benefit from it.  Having the defconfig
> > >> files contain only those options which are different from the defaults
> > >> is certainly more readable, even on x86.
> > >
> > > Quite possible. But maintainers would need to be on the lookout of
> > > people actually using the script, and refusing to apply patches that
> > > re-introduce the whole big thing.
> > 
> > I can (partially) speak for powerpc.  If ARM uses this approach, then
> > I think we can do the same.  After the defconfigs are trimmed, I
> > certainly won't pick up any more full defconfigs.
> I just restarted my script on the powerpc defconfigs basing on rc5, I
> assume they complete in a few days time.
So Stephen was faster than me.  I don't know yet how he optimised my
script, meanwhile I put some efforts into it, too by just checking lines
that match "^(# )?CONFIG_".

Find it attached.

I will start to reduce the remaining configs (i.e. all but arm and
powerpc).

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

[-- Attachment #2: reduce_defconfig --]
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#! /usr/bin/env python
# vim: set fileencoding=utf-8 :
# Copyright (C) 2010 by Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

import getopt
import re
import os
import subprocess
import sys

# This prevents including a timestamp in the .config which makes comparing a
# bit easier.
os.environ['KCONFIG_NOTIMESTAMP'] = 'Yes, please'

re_interesting = re.compile(r'^(# )?CONFIG_')

opts, args = getopt.getopt(sys.argv[1:], '', ['arch=', 'src='])

src = ''
arch = 'arm'

for o, a in opts:
    if o == '--arch':
        arch = a
    elif o == '--src':
        src = a

configdir = os.path.join(src, 'arch', arch, 'configs')

def all_defconfigs():
    lc = len(configdir)
    for root, dirs, files in os.walk(configdir):
        root = root[lc + 1:]
        for f in filter(lambda s: s.endswith('_defconfig'), files):
            yield os.path.join(root, f)

if not args:
    args = all_defconfigs()

for target in args:
    defconfig_src = os.path.join(configdir, target)

    subprocess.check_call(['make', '-s', 'ARCH=%s' % arch, target])
    origconfig = list(open('.config'))
    config = list(origconfig)
    config_size = os.stat('.config').st_size

    i = 0

    while i < len(config):
        mo = re_interesting.match(config[i])
        if mo:
            defconfig = open(defconfig_src, 'w')
            defconfig.writelines(config[:i])
            defconfig.writelines(config[i + 1:])
            defconfig.close()
            subprocess.check_call(['make', '-s', 'ARCH=%s' % arch, target])
            if os.stat('.config').st_size == config_size and list(open('.config')) == origconfig:
                print '-%s' % config[i][:-1]
                del config[i]
            else:
                print ' %s' % config[i][:-1]
                i += 1
        else:
            del config[i]

    defconfig = open(defconfig_src, 'w')
    defconfig.writelines(config)
    defconfig.close()

Re: optimized script [Was: ARM defconfig files]

[Olof Johansson]

On Tue, Jul 13, 2010 at 10:07:05AM +0200, Uwe Kleine-König wrote:
> Hello,
> 
> On Tue, Jul 13, 2010 at 09:07:41AM +0200, Uwe Kleine-König wrote:
> > Hi
> > 
> > On Mon, Jul 12, 2010 at 01:50:47PM -0600, Grant Likely wrote:
> > > On Mon, Jul 12, 2010 at 1:34 PM, Linus Torvalds
> > > <torvalds@linux-foundation.org> wrote:
> > > > On Mon, Jul 12, 2010 at 12:17 PM, Nicolas Pitre <nico@fluxnic.net> wrote:
> > > >> I think Uwe could provide his script and add it to the kernel tree.
> > > >> Then all architectures could benefit from it.  Having the defconfig
> > > >> files contain only those options which are different from the defaults
> > > >> is certainly more readable, even on x86.
> > > >
> > > > Quite possible. But maintainers would need to be on the lookout of
> > > > people actually using the script, and refusing to apply patches that
> > > > re-introduce the whole big thing.
> > > 
> > > I can (partially) speak for powerpc.  If ARM uses this approach, then
> > > I think we can do the same.  After the defconfigs are trimmed, I
> > > certainly won't pick up any more full defconfigs.
> > I just restarted my script on the powerpc defconfigs basing on rc5, I
> > assume they complete in a few days time.
> So Stephen was faster than me.  I don't know yet how he optimised my
> script, meanwhile I put some efforts into it, too by just checking lines
> that match "^(# )?CONFIG_".
> 
> Find it attached.
> 
> I will start to reduce the remaining configs (i.e. all but arm and
> powerpc).

I added just a simple heuristic: If I could remove a line, I attempted
to remove twice the amount next time around (and fall back to 1 if it failed).

I.e. main loop:

i = 0
lines = 1

while i < len(config):
    print 'test for %r + %d' % (config[i], lines)
    defconfig = open(defconfig_src, 'w')
    defconfig.writelines(config[:i])
    defconfig.writelines(config[i + lines:])
    defconfig.close()
    subprocess.check_call(['make', '-s', 'ARCH=%s' % arch, target])
    if os.stat('.config').st_size == config_size and list(open('.config')) == origconfig:
        del config[i:i+lines]
        lines *= 2
    else:
        if lines > 1:
            lines = 1
        else:
            i += 1


I didn't measure what the actual improvement was, but I saw a fair amount
of 2/4/8-attempts passing, so I let it run. Stephen beat me to posting
the resulting patch though. :P

While this script is great, it is somewhat painful to run given that it
attempts one config per line. Even on a fast machine that tends to take
a while.


-Olof

Re: optimized script [Was: ARM defconfig files]

[Nicolas Pitre]

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On Tue, 13 Jul 2010, Olof Johansson wrote:

> On Tue, Jul 13, 2010 at 10:07:05AM +0200, Uwe Kleine-König wrote:
> > Hello,
> > 
> > On Tue, Jul 13, 2010 at 09:07:41AM +0200, Uwe Kleine-König wrote:
> > > Hi
> > > 
> > > On Mon, Jul 12, 2010 at 01:50:47PM -0600, Grant Likely wrote:
> > > > On Mon, Jul 12, 2010 at 1:34 PM, Linus Torvalds
> > > > <torvalds@linux-foundation.org> wrote:
> > > > > On Mon, Jul 12, 2010 at 12:17 PM, Nicolas Pitre <nico@fluxnic.net> wrote:
> > > > >> I think Uwe could provide his script and add it to the kernel tree.
> > > > >> Then all architectures could benefit from it.  Having the defconfig
> > > > >> files contain only those options which are different from the defaults
> > > > >> is certainly more readable, even on x86.
> > > > >
> > > > > Quite possible. But maintainers would need to be on the lookout of
> > > > > people actually using the script, and refusing to apply patches that
> > > > > re-introduce the whole big thing.
> > > > 
> > > > I can (partially) speak for powerpc.  If ARM uses this approach, then
> > > > I think we can do the same.  After the defconfigs are trimmed, I
> > > > certainly won't pick up any more full defconfigs.
> > > I just restarted my script on the powerpc defconfigs basing on rc5, I
> > > assume they complete in a few days time.
> > So Stephen was faster than me.  I don't know yet how he optimised my
> > script, meanwhile I put some efforts into it, too by just checking lines
> > that match "^(# )?CONFIG_".
> > 
> > Find it attached.
> > 
> > I will start to reduce the remaining configs (i.e. all but arm and
> > powerpc).
> 
> I added just a simple heuristic: If I could remove a line, I attempted
> to remove twice the amount next time around (and fall back to 1 if it failed).
> 
[...]
> 
> While this script is great, it is somewhat painful to run given that it
> attempts one config per line. Even on a fast machine that tends to take
> a while.

The optimal solution is to add that .config reduction ability straight 
into the Kconfig parser (scripts/kconfig/*).  There you can find out 
right away what are the non default state for each config option without 
actually trying them out one by one.


Nicolas